smile design
TRANSCRIPT
Smile designTABLE OF CONTENTS
INTRODUCTION
DEFINITIONS
PHYSICAL ATTRIBUTES OF THE ELEMENTS OF THE DENTO-FACIAL
COMPOSITION
PERCEPTUAL ASPECTS – THE ART OF ILLUSION
ESTHETIC DIAGNOSIS AND TREATMENT PLANNING
ROLE OF TECHNOLOGY IN CHANGING SMILE
ESTHETIC TREATMENT PLANNING AND SEQUENCING
COLOR
DENTAL BLEACHING
ESTHETICS WITH COMPOSITES
ESTHETICS WITH CERAMICS
IMPLANT – ESTHETICS
PERIO – ESTHETICS
ORTHO – ESTHETICS
REVIEW OF LITERATURE
CONCLUSION
REFERANCES
Smile design
INTRODUCTION
In our modern competitive society, a pleasing appearance often means the difference between
success and failure in both our personal and professional lives. Scottish physiologist Charles bell
(1774-1842) was quoted as remarking that the thought is to the word that the feeling is to the
facial expression. He pointed out in 1806 that a smile could convey a thousand different
meanings, yet it is the most easily recognized expression. And because the mouth is one of the
focal points of the face , it should come as no surprise that the smile plays a major role in how
we perceive ourselves, as well as in the impressions we make on the people around us.
A charming smile can open doors and knock down barriers that stand between you and a
fuller, richer life. An attractive or pleasing smile clearly enhances the acceptance of the
individual in the society where he belongs and the character of the smile influences the
attractiveness and the personality of the individual.
CLASSIFICATION OF SMILE(Solomon E.G.R.)
1) Depending on the nature of labial mucous membrane
a) Papilla smile
b) Gingival smile
c) Mucosa smile
2) Dependant on the lip component
a) Straight smile
b) Convex smile
c) Concave smile
Smile design
DEFINITIONS:
Glossary of Prosthodontic terms January 1999.
Esthetics
1. Pertaining to the study of beauty and the sense of beautiful. Descriptive of a specific
creation that results from such study; objectifies beauty and attractiveness and elicit
pleasure.
2.
Pertaining to sensation
Esthetic reshaping
Modification of the surfaces of teeth to improve appearance
Esthetics (adj. 1798)
1. The branch of philosophy dealing with beauty.
In dentistry, the theory and philosophy that deal with beauty and beautiful, esp. with respect to
the appearance of a dental restorations, as achieved by its contour and color.
Those subjective and objective elements and principles underlying the beauty and attractiveness
of an object, design or principle
Dental Esthetics
Smile designThe application of the principles of esthetics to the natural or artificial teeth and restorations
(GPT 1999)
Esthetic Dentistry
Can be defined as the art and science of dentistry applied to create or enhance beauty of an
individual within functional and physiological limits. (Ratnadeep Patil)
Cosmetic dentistry: is application of the principles of esthetics and certain illusionary
principles, performed to signify or enhance beauty of an individual to suit the role he has to play
in his day-to-day life or otherwise. (Ratnadeep Patil)
Smile designing
Is a process whereby the complete oral hard and soft tissues are studied and evaluated and
certain changes are made which will have a positive influence on the overall esthetics of the face.
These changes are governed by the principles of esthetic dentistry. Hence, a good smile design
Would naturally and effortlessly blend with the rest of the face to provide an esthetic and
functional complex .
“A well designed smile is a product of consolidated efforts accomplished by accurate
diagnosis, methodical treatment planning, use of advanced materials and contemporary
techniques rendered by the skilled dentist”.
PHYSICAL ATTRIBUTES OF THE ELEMENTS OF THE DENTO-FACIAL
COMPOSITION
The artistic parameters to be considered for essential beauty and those which are subtly present
in natural beauty form the fundamental principles of esthetics. Understanding these artistic
parameters of beauty and co-relaing them to the dento-facial complex will enable the dentist to
appropriately scale esthetics in any dento-facial composition.
Smile design
Composition means the act of combining elements or parts to form a whole. There are various
physical attributes of the elements of a composition that impart the esthetic value. The various
physical attributes of the elements of a composition are:
Contrast:
It is that factor which makes the various elements of a composition visible. The eye can
differentiate the parts of an object due contrast of colors,lines, patterns, textures, etc. The
relationship between the different parts of the face (facial), the teeth and the gums (dental) made
visible by contrast constitutes the dento-facial composition.
Unity or oneness : “It gives different elements of the composition the effect of a whole”. Unity
can either be static, when repeated shapes or designs are seen as in inanimate things, like the
composition of crystals; or dynamic and changing as in living beings. Unity between different
parts of the face, and teeth is essential to give the effect of oneness to the dento-facial
composition.
Cohesive and segregate forces :
Any element which tends to unify a composition is a cohesive force. Segregative forces are those
elements which break the monotony of the composition. Naturalness has combination of
cohesive and segregative forces. A proper mix of segregative and cohesive forces makes dento
facial composition dynamic.
Smile design
Symmetry: It is the mirror image of one side of face to the other side of face.
It can be
horiregularity of arrangement of forms either from left to right as in horizontal symmetry, or
from a central point to either side like a mirror image as in radiating symmetry. The horizontal
symmetry looks repetitive and uninteresting while the radiating symmetry looks dynamic and
interesting. In a dento-facial composition radiating symmetry of the teeth is more esthetically
appealing and is associated with youthfulness while horizontal symmetry is less appealing and is
associated with aging.
Proportion : To be able to give a certain mathematical representation of beauty for numerically
expressing the relationship of the various units that combine to make a composition, the term
proportion is used.
The relationship of the various units which are different from each other in a composition but are
associated with each other through a certain repetitive mathematical factor is the repeated ratio.
The proportion between the various elements of a harmonious composition, in which the
cohesive and segregative forces are equally balanced,and whichhas its various units in an
esthetically appealing respective proportion to each other is the golden proportion
Smile designDominance: It exists when a strong centralized structure is surrounded by well-demarcated,
characterized structures. In a dento-facial composition it creates immaculate unity leading to a
harmonious compaosition. The absence of dominance makes the composition weak. Color, shape
and size are the factors which can control dominance.
Balance: It is achieved when there is an exact equilibrium between the forces present on either
side of the fulcrum in a composition. In dentistry this implies the balance of the elements in
relation to the midline. If any elements are imbalance on one side then, to create a visual balance
either these elements are moved towards the midline or are counter-balanced with opposite
elements to regain the balance. In balance the weight of the elements far away from the fulcrum
grows in importance.
Smile design
Visual tension is the tension brought about by the presence of certain elements that cause an
imbalance in the given composition. If the presence of these factors is closer to the fulcrum, the
effect of the tension into the fulcrum,the effective the tension induced is more magnified as
against their presence further from the fulcrum. A distally inclined lateral incisor on one side is
compensated by a more mesial inclination of the first premolar on the opposite side to reduce the
effective visual tension. These variations are naturally found in dentitions explaining the reason
why sometimes irregularities in inclinations still produce pleasant smiles.
The esthetic orientation of the dental composition with the entire facial composition can be
achieved by taking into consideration the references, smile elements, proportions and symmetry.
These are the factors of esthetic compositions and they help the dentist in determining tooth
display, size, arrangement and alignment during the diagnosis and treatment phase.
The dento-facial frame constitutes the teeth and gingiva related to the lips and then to the entire
face. The oral frame is determined by the anatomy and mobility of the tissues when in function
surrounding the teeth and gingiva .The exposed portion of the oral elements i.e. teeth and gums
within the oral frame during a smile is called the smile window.
The anatomical elements of the face and the biological elements that include the functional and
phonetic elements, provide the reference frames, guidelines and points. These elements help the
dentist to achieve a general sense of orientation and diagnosis.
Smile designReferences can be classified as horizontal references, vertical references, sagital references and
phonetic references.
Horizontal references: The horizontal perspective of the face is provided by the interpupillary
line the commissural line.
The inter-pupillary line helps to evaluate the orientation of the incisal plane, the gingival
margins and the maxilla. An imaginary horizontal line through the incisal plane and the gingival
margins should be visibly parallel to the inter-pupillary line. This helps to diagnose any
asymmetry in the tooth position or gingival location. When an imaginary line is drawn across the
gingival margins, it may not be parallel to the inter-pupillary line indicating a certain degree of
canting of the maxilla.
Certain amount of canting of maxilla is considered normal and in such cases mild correction of
the gingival margins can achieve a pleasing symmetry Severe canting may require an inter-
disciplinary approach involving surgical repositioning of the maxilla.
Vertical references: The facial midline serves to evaluate the location and axis of the dental
midline and the medio-lateral discrepancies in tooth position.The inter-pupillary line and the
facial midline emphasize the ‘T’ effect in a pleasing face. The dental midline, if perpendicular to
the inter-pupillary line and coinciding with the bridge of the nose and the philtrum, produces an
attractive orientation of the smile.
Axial inclination is the direction of the anterior teeth in relation to the central midline and
becomes progressively more pronounced from the central incisor to the canine. There is a
definite mesial inclination to all the anterior teeth related to the midline. The axes of the
Smile designpremolars and the first molar on either side also show mesial inclination in relation to the
midline.
The perception of tooth inclination can be viewed from the frontal aspect around the central
vertical midline, which acts like a fulcrum around which axial inclination of teeth on either side
exhibit a phenomenon of balance of lines Natural smiles show a deviation from these standard
axial inclination. Deviations in axial inclination cause a visual tension when beyond the point of
equilibrium
Sagittal references: Soft tissue analysis at a standardized position helps in studying the profile of
an individual. The contours of the upper and lower lip support is determined by the position of
the anterior teeth and can be used as a guide for the placement of teeth when planning
restorations. The lip protrusion, the amount of prominence of chin, recession or prominence of
the nose and its degree, all help in profile analysis for diagnosis and treatment planing.
The E-line or esthetic line is an imaginary line connecting the tip of the nose to the most
prominent portion of the chin on the profile, ideally the upper lip is 1-2 mm behind and the lower
lip 2-3mm behind the E-line. Any change in the position of the E-line indicates the abnormality
in the upper or lower lip position.
Smile designThe main support of the upper lip is contributed by the gingival two thirds of the maxillary
central incisors rather than the incisal one third According to studies by Maritato and Douglas
the lip support is a better guide of tooth position than of incisal edge position.
The relationship of the maxillary incisl edges to the lower lip is a guide for the placement of the
incisal edge position and length. The pronunciation of the ‘F’ and ‘V’consonants helps determine
the position of the incisal edges. On pronouncing ‘F’ and ‘V’ the incisal edges should make a
definite contact at the inner vermilion border of the lower lip Thus the position of the incisal
third of the maxillary central incisor can be determind.
Phonetic references: Phonetics play a part in determining maxillary central incisor design and
position. ‘F’ and ‘V’ sounds are used to determine the tilt of the incisal third of the maxillary
central incisors and their length. The ‘M’ sound is used to achieve relaxed rest position and
repeated at slow intervals can help evaluate the incisal display at rest position ‘S’ or ‘Z’ sounds
determine the vertical dimension of speech.. Its pronunciation makes the maxillary and the
mandibular anterior teeth come in near contact and determine the anterior speaking space The
amount of posterior speaking space varies with the amount of mandibular protrusion necessary to
bring the anterior teeth in near contact for the ‘S’ sound.
Smile elements: The extent of the smile is outlined by the curvature of the upper and lower lip
and the position of the angle of the mouth, and it determines the degree of exposure, both in the
anterior and posterior teeth, gingiva as well as the width of the buccal corridor
Smiles can be classified as passive, active (moderate) and laugh. In a passive smile the lips are
parted slightly away from the rest position expressing content, passion, desire, surprise, etc. In an
active smile the lips move to a significant extent away from the rest position displaying more
Smile designteeth and even gums, expressing joy, welcome, happiness, etc. Laugh is an instant fluctuation
from an active smile position where the facial muscles instantly act leading to maximum
exposure of the teeth and gums. Humorous and funny situations usually lead to such an
expression.
Lip and lip lines: The length, the curvature and the shape of the lips significantly influence the
amount of tooth exposure during rest and in function.
A prominent tooth display is associated with a youthful smile and most patients would like to
seek the benefit of the same. Some researchers demonstrated that the average maxillary incisor
display with the lips at rest is 1.91mm in men and 3.40 mm in Women Patient’s with short upper
lips and younger patients generally display more maxillary tooth structure which may be up to
3.65mm.
Upper lip line helps to evaluate the length of the maxillary incisor exposed at rest and during
smile and the vertical position of the gingival margins during smile.
The upper lip line can be classified as low, medium or high depending upon the amount of tooth
or gingival display that is available at rest of during a moderate smile. The gingival margins may
be displayed in high lip line cases. The most apical position of the gingiva over the facial aspect
of the maxillary central incisor and canine is slightly distal to the long axis of the tooth while in
the maxillary lateral incisor it is at the long axis of the tooth. This is called the gingival zenith.
Whenever a patient displays the gingival margins easily on smiling or speaking, a definite
pattern of the gingival display can be recorded. This pattern can be either esthetic or unesthetic A
smile can be termed “toothy” if more than 6mm of incisal display is seen at rest position or
“gummy” if more than 3mm of gingival tissues are displayed in moderate smile.
Smile designLower lip line helps to evaluate the buccolingual position of the incisal edge of the maxillary
incisors and the curvature of the incisal plane
Smile line: It is an imaginary line passing through the incisal edges of the upper anterior teeth.
The smile line usually coincides or runs parallel to the inner vermilion border of the lower lip. In
a youthful smile the incisal edges of the central incisors and canines are aligned on a convexity
and are linger than the lateral incisors, incisal embrasures gradually deepen from central incisor
to the canine, giving the appearance of the wings of a gull. Thus the incisal plane is said to have
a gull-wing apperance when the incisal edges of the central incisors and canines are aligned on a
convexity the incisal plane is convex. Reduced incisal embrsures and leveling of the gull-wing
effect as in a straight smile line is associated with aging.
Negative space: Negative space is a dark space appearing between the jaws and the mouth
opening either at the corner of the mouth of around the buccal aspect of the posterior teeth during
active smile and laugh.The lateral negative space exists between the labial surface of maxillary
teeth and the corner of the mouth while the buccal negative spaces appear in the buccal vestibule
on either side of the buccal aspect of posterior teeth.
Obliteration of these essential spaces by dental elements like bulky canines, wide arches or over-
contoured restorations can lead to an unattractive smile.
Smile designExcessive negative space seen in cases of missing premolars orA palatally placed posteriors and
a constricted arch also appear unesthetic.
Progressive abating in a dental composition : When similar structures are aligned in an arch
form one after the other, they appear to progressively abate in size from the nearest to the
farthest. This gives an illusion of depth.
The essential requirement of the front to back progression in dental composition is the
alignment of the contour of the labial and surface at the incisal third, middle third and the
gingival third of successive teeth in the arch. The incisal mesio-buccal inclines should be well
aligned to give a smooth progression from tooth to tooth. The buccal and lateral negative space
progressively reduces the illumination on teeth to enhance the front to back abating effect. The
presence of poorly shaped teeth, differences in axial inclinations, tooth length discrepancies,
discolorations, gingival disharmonies etc. can lead to a visual tension resulting in a disruption of
the front to back progression.
Proportion
When mathematics is applied to the study of ideal tooth form, a numerical relationship is
established within a single tooth form (ideal proportion) and also between a series of teeth in the
arch (relative proportion). The position of the tooth in the arch, the relationship between the
width, the length and the face of the tooth can also be numerically established in relation with
certain anatomic landmarks.
Smile designGold Proportion is expressed in numerical form and applied by classical mathematicians such as
Euclid and Pythagoras in pursuit of universal divine harmony and balance. It has been applied to
a lot of ancient Greek and Egyptian architecture and may be expressed as the ratio 1.618:1.
If the ratio is applied to the smile made up of the central, lateral incisor and the mesial
half of the canine, it shows that the central incisor is 62% wider than the lateral incisor which in
turn is 62% wider than the visible portion of the canine which is the mesial half, when viewed
from the front.
Application of sizing the central incisors from certain facial measurements is known as the 1 to
16 theory, whereby the height of an ideal maxillary central incisor from the incisal edge to the
gingival crest is 1/16th of the distance from the inferior border of the chin to the inter papillary
line. The same tooth width can be measured from the mesial to distal contact areas and is 1/16th
of the distance measured from either zygomatic prominence through an imaginary facial midline.
Once the size for the central incisor is determined it is essential to design its outline form. The
facial harmony method can be applied to relate the tooth form to the facial form. Various facial
shapes are identified and descriptions such as avoid, square, tapered and combinations of these
are used The same shape when inverted can be applied to the central incisor design. This shape
acts as guideline for the outline forms of other maxillary teeth.
In an attempt to determine the original anterior tooth placement on the ridge, the position of the
incisive papilla is considered as an important land mark as it position does not alter even after
bone resportion of the anterior ridge. The distance between the posterior border of the papilla to
the outer labial surface of the central incisor averages to about 12.5mm with a variation of
approximately 3.8mm. The end of the first palatal ruga is located 1.5 mm to 2mmm from the
lingual surface of the canine. Many dentists have also recorded the averages distance between
the base of the sulcus and the tip of the maxillary incisor. This distance is measured 22mm.
This helps the dentist to determine the tooth position in the vertical plane.
Smile design
Symmetry
For harmony, certain symmetries are essential while certain asymmetries are acceptable.
Harmonious facial features should be more symmetrical close to the facial mid line and can be
more asymmetrical away from the facial midline.
Pleasing Smile
A naturally attractive smile that evokes a feeling of beauty or harmony and complements
the personality of the bearer is termed as a pleasing smile.
The natural pleasing smile may not necessarily comply with all rules of sy
mmetry or golden proportion or may not exhibit perfect balance without irregularity of shape.
However, the composition is esthetically appealing with unity within its various elements.
Smile Dominance: Different facial features stand out differently in the eyes of every beholder. In
certain cases, the most predominantly striking features of a face are the smile; these are the
“Dominant Smiles”.
The distinguishing characteristics observed in people with pleasant smile dominance that
can be used as a guideline for creating the same are:
The maxillary central incisors exhibit a strong presence by their size and form reflecting
the personality of the individual.
The maxillary lateral incisors and the canines complement the cement incisor in terms of
proper shape and form.
Smile design Although numerically all proportions of the anterior teeth do not follow the rule of golden
proportion, the teeth are so placed that they appear in suitable proportions with each other.
Smile recurring ratios are observed in the teeth from the central incisor to the premolar.
Well co-ordinated movements of the lips with the other peri-oral musculature and
corresponding harmonious facial expressions, contribute to the pleasant face during smile.
The complexion and texture on the face contrast with the lip color, gingival and the teeth
leading to a distinct demarcation between the oral and the facial frame.
PERCEPTUAL ASPECTS – THE ART OF ILLUSION
Illusion is a figment of imagination where a perception of an object is created.
Fundamentals and Principles
The art of creating illusions consists of changing perception, to cause an object to appear
different from what it actually is. Teeth can be made to appear smaller, larger, wider, narrower,
shorter, longer, younger, older, masculine or feminine.
One is subjected to light the most fundamental objects exhibits two dimensions, that is,
length and width. True natural light is multi-directional and on striking the surface of the object,
also reveals texture and shadows, this adds the third life like dimension of depth.
Illusion works on two basic principles which are the principle of illumination and the principle of
light. The most important of these is the perception that light approaches and dark recedes. This
is termed as the ‘Principle of Illumination”. The second artistic predilection of great
importance in dentistry is the use of horizontal and vertical lines and ridges. Horizontal lines
Smile designmake the object appear wider and vertical lines make the object appear longer. This is termed as
the “Principle of Line”.
The artistic predilection exhibited in the principle of illumination can be maintained to change
the size, shape and the overall form of the tooth through illusions.
Law of the face. The face of a tooth is that area on the facial surface on both anterior and
posterior teeth that is bound by the transitional line angles as viewed from the facial i.e. labial or
buccal aspect. These transitional line angles mark the transition from the facial surface to the
mesial, distal, and cervical and incisal surfaces. The tooth surface slopes lingually in the mesial
and distal region while it slopes cervically from the line angles towards the root surface.
Whenever there is no transitional line angle demarcating the incisal portion of the facial surface,
the face is bound by the incisal edge or the occlusal tip.
Shadows created as light strikes the facial surface of the tooth begin at the transitional line
angles, these shadows delineate the boundaries of the facial form. Thus the apparent face is that
portion of the face that is visible to the observer from any single view. When maxillary anterior
teeth are viewed from the front only the mesial half of the canine is visible however the entire
incisor face is visible.
The law of the face implies making dissimilar teeth appear similar by making the apparent faces
equal. The apparent face should be manipulated, not the actual face. This is more important in
the canines and the posteriors as the ‘apparent face’. The transitional line angles are relocated so
that the apparent faces look equal, however this results in dissimilar areas outside the transitional
line angles.
Similar faces produced attract light and appear high lighted while the dissimilar areas that
are in a shadow appear to recede.
Smile designWhen the transitional line angles cannot be repositioned on a restoration, then the portion
of the tooth can be stained darker to create an illusion that the transition line angle has been
moved.
Cosmetic contouring
Cosmetic contouring by definition is the reshaping of natural teeth to make them
esthetically pleasing.
In natural dentitions, variations seen in tooth shape and size some times violate the
acceptable width to length ratios as well as the golden proportion. Minor adjustments in
contours to change the perception of these proportions increases the esthetic acceptability to a
great extent. It is indicated for giving a pleasing appearance to fractured, chipped, extruded,
malformed or over lapped teeth .
The procedure is contra indicated in hypersensitive teeth, teeth with thin or defective enamel
formation or large pulp chambers.
The upper lip line should be used as a reference to see how much tooth is visible when
the patient smiles. The lower lip line will help to create a pleasing smile line. Tooth visibility
with lips at rest, when the patient talks or smiles should also be assessed. The dentist should view
the patient in sitting and standing positions.
Procedure
The procedure involves minimum tooth reduction confined to enamel. Changes on the
tooth surface of the related tooth are carried out by working on the transitional line angels, height
of contour, incisal and facial embrasures and adjusting incisal edge and angels. Finishing disks
are used to open incisal embrasures and the reshaped teeth are then thoroughly polished with a
Smile designfine grit diamond paste and application of fluoride gel or foam is recommended to minimize any
chances of postoperative sensitivity.
ESTHETIC DIAGNOSIS AND TREATMENT PLANNING
Total Smile Analysis
Total smile analysis is a cumulative inference analysis, drawn by interpreting and integrating
various analysis like a visual, space profile and computer analysis after performing the
preliminary analysis.
Space Analysis
It helps the dentist to gauge the amount of space available during the treatment planning
stage. The concept is to measure the widths of all the
teeth and to compare it with space present in the arch. This determines whether the space
available for restorations and natural teeth is less or more than required.
Disproportionate spaces may be due to discrepancies in jaw and tooth size, malformed
teeth, missing teeth, mal-aligned teeth etc. The space analysis will provide a guideline or a
frame work within which the esthetic dentist has to plan each restoration.
Corrections of labio-lingual inclinations and rotations of the teeth by restorative procedures will
result in a change in the width space ratio due to the change of angulation involved.
It may not be possible to match all teeth on either side of the midline due to space or
morphological constraints, but in order to preference they should be matched as far as possible
Smile designstarting from the midline and proceeding towards the canines. Symmetry and dominance of the
central incisors being an important element of the pleasing smile should not be compromised as
far as possible.
For any changes proposed that may involve alterations in the width of the anterior teeth,
the law of golden proportion should be closed followed. This enables the esthetic dentist to plan
any space manipulations for the restorations in terms of illusions, actual tooth positional changes
such as rotations overlaps, spacing etc.
. Profile analysis
While examining the patients profile, the normal profile is referred to as straight
orthognathic. Any deviation from this should be recorded and considered in treatment planning.
Examination of the profile could be in the antero-posterior plane or in the vertical plane.
Computer Analysis
Radiographs and photographic images have been used as an essential aid in diagnosis,
record keeping, communications and treatment planning. Computer aided technology has
broadened the scope of applicatiosn as well as enhanced the utility of radiographs and
photographs in the dental field. The new intra-oral cameras with digital support and the radio-
visiographs are indispensable tools at the esthetic dental office.
They give enlarged images of the photographic and radiographic outputs on the screen, without
the involvement of any hard copies of photographs or radiographs, with multiple magnifications,
and at various angles, for the dentist as well as the patient to assess and view the intra oral
condition in a different perspective. the proposed treatment modalities may bring about without
actually carrying out the treatment.
In a particular case, esthetic enhancement with a change of arrangement, form, shape or color
can be demonstrated quickly. Thus computer analysis can be used as a quick reference which
Smile designcan guide the future artistic creations that the dentist may consider, however, the occlusal
parameters cannot be addressed without appropriate devices and hence the actual three
dimensional aspect of the change cannot be applied without error. Promising the patient results
close to what are seen through a computer analysis could lead to dis-satistication and hence the
dentist should consider other diagnostic means before designing definitive treatment plans.
ROLE OF TECHNOLOGY IN CHANGING SMILE
New technology helps us to preview the end results.The following high tech tools can be
incorporated:
1) Extra oral video camera :
It allows to have a detailed record of the patient's face while moving and talking- a
much more helpful tool than a still photograph. It can record the patient in various moods and
gestures and give us the minute details the patient may be unaware of. This can be shown to the
patient with the help of computer imaging . Different smiles and profiles can be applied to the
patient's face and the patient can be given the opportunity to choose the best smile design .
2) Intraoral video camera :
It is an easy to use unit designed with reliability, performance and image quality. Intra
oral examination from every angle with the smallest details can be viewed as close as 2mm. fron
the tooth. With it we can explain certain conditions and treatment options much more accurately
than with sketches, mirrors and X- rays. Introral cameras can be integrated with a computer
imaging system to capture the detailed images of the patient's oral cavity. These images can be
modified according to the proposed treatment options and shown to the patient. At the click of
the mouse a particular tooth can be elongated or widened , the effect of which can be shown to
the patient for his approval.
Smile design3) T- Scan and Digital Radiography
By using this scan , buccolingual width of the jaws as well as the location of anatomic
features such as the mandibular canal and the maxillary sinus can be determined which is useful
while placing an implant in the esthetic position.
Now-a-days manufacturers promote digital radiography system and video camera in one
unit i.e. single hand piece which will be concenient for use.
4) CAD/CAM
With CAD/CAM ( Computer assisted design/ Conputer assisted manufacture) technology
we can design veneers and crowns to enhance smile while the patient waits. The so called
"mock- up" of a planned cosmetic teatment also has been shown to be quite useful. It also allows
clinician to visualise the desired results and solve potential problems before providing treatment
to the patient.
5) Lasers
The dental lasre uses a beam of light in place of scalpel to perform delicate gum surgery
and crown lengthening/ gingivectomy and gingivoplasty.
The advantages of this procedure are-
1) Controlled bleeding which provides dry operating field and hence excellent
visibility.
1) Reduced operating time and reduced post operative swelling, pain and scarring.
6) Computer Imaging
It improves communication between the patient and the dentist by allowing both to visualize
, evaluate and agree on treatment. It allows to " see" various looks before deciding upon
treatment.
7) Abrasive Technology
Smile design In this technique , a jet air stream with micro abrasive particles is used to remove the stained
areas. It is painless, faster and does not require the use of anesthesia. It can be used in any
quadrant for any depth of decay without damaging the healthy tooth structure. After the removal
of the stained areas , the tooth structure can be built up with composite.
It is also useful during repairs to existing composite or porcelain restorations because it
roughens these surfaces allowing the reparative materials to bond them more rapidly .
Occlusal considerations
The esthetic dentist has a major challenge in dealing with restorative situations in the
mouth where occlusal considerations are critical. Natural and restored maxillary and mandibular
teeth should have optimal functional contact relationship resulting in the even distribution of
load in static and dynamic positions leading to minimal trauma of the teeth and supporting
structures. This requires a thorough understanding of the stomatognathic system which
comprises of the temporomandibular joint, the ligaments, related musculature and the dentition
and their coordinated three dimensional movements.
Concept of occlusion
A thorough knowledge of the various concepts of articulation accompanied with
application of the same is mandatory for successful restorative rehabilitation.
The various concepts of occlusion are
Bilateral balanced occlusion
Group function or unilateral balanced occlusion
Mutually protected occlusion
Smile designIn large or complex rehabilitation’s with fixed prosthesis, a sequential and correct method of
recording the jaw relations should be followed since any error would be magnified in the final
outcome. This would be detrimental to the survival of the surrounding tissues and the restoration.
The hinge axis of the mandible should recorded with a kinematic face bow and transferred to an
adjustable. Arbitrary hinge axis face bow is useful for routine work and gives a fairly accurate
relationship (error of 5mm). Correct centric relationship and protrusive and lateral inter occlusal
records are made in rigid materials and the articulators are adjusted accordingly. Correct incisal
guidance is computed and adjusted. This logical and systematic approach ensures minimum
error.
Forces on the dentition
On the dentition it is influenced by several factors like position of the teeth in the arch,
masticatory dynamics, relationship with the opposing arch, crown-root ratio, direction, duration,
frequency and character of the forces during functional mandibular movements and
parafunctional habits. The peri-oral musculature and the tongue exert a constant force on the
teeth. These forces are lighter and in a horizontal direction. Swallowing also exerts forces on a
continuous basis throughout the day. The peri-oral musculature and the tongue exert a constant
force on the teeth. These forces are lighter and in a horizontal direction. Swallowing also exerts
forces on a continuous basis throughout the day. The heavier natural forces exerted on the teeth
are during mastication and are primarily directed perpendicular to the occlusal plane in the
posterior region. They are exerted infrequently and for a short duration during the day.
In mutually protected occlusion, where there are no posterior contacts in eccentric movements,
fewer fibers of the temporalis and masseter muscles and stimulated resulting in reduction of the
forces applied on anterior teeth by two thirds.
Smile designResearch on implant prosthesis and crowns with cast cores on maxillary incisors have
shown permissible angle of up to 25° between the crown and root for maintenance of adequate
periodontal health.
Parafunctional movements: Are identified as a cause for occlusal wear and excessive forces.
Parafunction can be related to local factors like malocclusion or to systematic factors like
cerebral palsy, epilepsy and can also be stress or occupation related. Bruxism, clenching and
parafunctional tongue thrust are the important parafunctions which the dentist should consider in
the treatment planning stage.
Bruxism: Rehabilitation of these cases not only involves elimination of the causative factors but
establishment of correct anterior incisal guidance to eliminate all posterior contacts during
mandibular excursions.
Clenching: Is the force exerted from one occlusal surface to other without movement. These
forces are directed more vertically to the plane of occlusion in the posterior region of the mouth.
Fremitus is often found in the clenching patient. This is vibratory type of a force felt with a
finger kept in contact with the facial aspect of a tooth while the patients taps the teeth together.
It is noticed clinically on many cervically eroded teeth, and if the occlusion is carefully
evaluated, it shows signs of excessive forces. This cervical defect is called cervical abfraction.
During the management of these cervical defects occlusal adjustments need to be considered
along with adhesive restorative methods for a long term success.
Parafunctional tongue thrust: Is an unnatural tongue force which can exert an abnormal
horizontal force on the anterior teeth.
Smile design
Esthetic treatment planning and sequencing
Treatment sequencing is an integral part of treatment planning. It is a phase wise
distribution of treatment procedures which will be programmed or charted considering periods of
healing, patient convenience, inter disciplinary treatment modalities and is the fundamental
feature of a meticulous treatment execution .
Although some basic periodontal, pulpal and temporomandibular problems would be addressed
at the initial therapy stage, more definitive periodontal or pulpal treatment may be necessary
during the definitive therapy stage. Certain cases involving endodontic posts or implants etc in
the esthetic zone may pose a challenge to the dentist in term of giving suitable interim
restorations that will not interfere with the healing process.
Mock up
Mock ups are made for diagnostic reasons during the treatment planning phase as well as
for reference purposes during the treatment phase. For the cases requiring major esthetic
correction involving many anterior teeth the dentist can work on the space availability and
allotment for every tooth on the mock up even before proceeding for the tooth preparations.
A cosmetic preview with the help of composite resins is the easiest and fastest procedure to help
the dentist in diagnosis, treatment planning as well as creating references during treatment
execution
Composites can be put on the facial tooth surfaces including spaces or even the gingiva to
determine the change of position of teeth desired at the final restorative phase. The dentist can
show this preview of the patient and get his opinion regarding tooth position, shade, shape etc.
The occlusion usually will restrict the restorative ease in many cases. The lower incisors
should be thoroughly examined and the contacts of the palatal aspect of the upper teeth marked.
Smile designThe functional movements in the mouth can also be checked at this time to determine any
potential occlusion
Obstructions or difficulties that may arise at the time of treatment. Some adjustment in the
incisal edges of the mandibular incisors might be mandatory before proceeding with esthetic
correction for the maxillary anteriors.
In cases requiring reduction of tooth structure like in overlapping teeth, a diagnostic wax-
up would be more beneficial as the required reduction of the teeth can be done on the study casts
and suitable colored wax-up can be used to visualize the end result and preparation design.
In cases requiring closure of spaces and where crown lengthening could be required to improve
the width to length ratio of the final restorations, a composite preview could be easily used.
Before crown lengthening procedures the extent of gingivectomy and the exact contour to be
established on the facial aspect contour to be established on the facial aspect is determined by the
location of the gingival zenith after the placement of the final restoration. Hence a composite
preview is used to determine the gingival contour and the gingivectomy is performed according
to this reference. Once crown lengthening is achieved and after sufficient healing period elapses,
composite or ceramic veneer is placed to give the final desired result
COLOR
Dimensions of color
Color cannot be perceived without light, which is a form of electoro-magnetic energy
visible to the human eye. The visible spectrum of light lies in a narrow band of 380nm to
760nm. It has the ability to stimulate the cells in the retina which is interpreted by the brain,
discerning the sense of color.
Smile design
Clark stated that “Color, like form, has three dimensions”. Hue, which is the name of the radiant
energy, Chroma, which is the saturation of the hue and value, which is the relative lightness or
darkness of the color. Since clinical color matching depends upon the ability of the dentist to
perceive the difference in the tooth shade guide comparison; complete understanding of the color
dimensions in critical.
The Munsell color order system best serves the needs of the dental profession in its tempt
to visualize and organize color.
Hue: In Munsell’s words, “It is that quality by which will distinguish one color family from
anther”.
Generally there are six hue families. Violet, blue, green, yellow, orange and red. For
example, in the Vita shade guide there are four hues A, B, C and denoting reddish brown,
reddish yellow, grayish and reddish grey respectively.
Chroma: In Munsell’s words, “it is the quality by which we distinguish a strong color from a
weak one. “Human teeth fall into the yellow to yellow red area of the Munsell color order
system. Pale colors have a low chroma whereas intense colors have high chroma
Value: Value or brilliance is the relative blackness or whiteness of color. On a scale of black to
white, white has “high value”, black a “Low value” and Midway between black and white is the
medium grey. Value is the only dimension of color that can exist by itself.
Opacity and Translucency: As light strikes a surface, it is either totally reflected, totally
absorbed or a combination of both. Opaque objects reflect all or most of the light that is incident
on them whereas transparent objects transmit all of the light that is incident on them.
Smile designWhen part of the light incident on an object is transmitted, while the rest is scattered, the
property of the object is known as translucency. It decreases with increasing scattering within
the materials.
Translucency, in effect, is the three dimensional spatial relationship or representation of value.
Highly translucent teeth tend to be lower in value, since they allow light to transmit through the
teeth, while opaque teeth have higher value.
There might be inter tooth as well as intra tooth differences in the translucency. Its extent
can vary according to the age of the patient due to the degenerative and reparative changes in the
enamel and dentin. To mimic natural teeth the effective use of restorative materials should
largely depend upon this translucent effect.
Metamerism
The change in color perception of two objects under different light sources is called
metamerism. For example, a shade guide tooth matches the natural tooth under incandescent
light but not under fluorescent light. This can be attributed to the difference in the radiant energy
of two different wavelengths of light.
The standardization of lighting condition during hade matching diminishes the effect of
metamerism.
Fluorescence
The emission of light by an object at a different wavelength from that of the incident light
is called fluorescence. The emission stops immediately on removal of incident light. Teeth
fluoresce with a stimulus in the range of 340nm to 410nm. This spectrum is in the blue range.
Smile designThus, according to the principles of additive color, the emitted blue light acts with the
yellowness of the tooth to produce a whiter tooth. Fluorescing pigments incorporated in the
ceramic restorations by the ceramist and in the composite restorations by the manufactures may
thus be advantageously used in altering the perception of the final result.
Gloss: Gloss is an optical property associated with a smooth surface that produces lustrous
surface appearance and thus reduces the effect of color differences. Increase the brilliance
(value0 of the final result.) In dentistry, unlike spectral colors, the restorative materials have
pigment colors incorporated in them.
Perception of color.
The perception of color involves many physiological , physiological and physiological
aspects
The light source.
The light source has the color of the emitted light and is described in color temperature
(Kelvin.). The lighting environment makes significant differences in the perception of color.
The teeth and the shade guide should be sufficiently illuminated. The light reflected from a
glossy surface obscures the viewer’s perception of light. Shadows should be eliminated as they
reduce the available light and hide details.
The dental operator maybe illuminated by combination of natural sunlight and artificial light, the
artificial light may be incandescent (predominantly) blue. Also the ratio between the task light
Smile design(which falls directly on the working area) and the ambient light (derived from the surroundings),
known as the contrast ratio, should be higher than 3:1, but lower than 10:1. This can be attained
by regularly measuring the intensity of light, cleaning the diffusers and the light sources any by
replacing them when their effective life is over.
The observer
The stimulus of light travels through cornea, lens, aqueous and vitreous humors and
reaches the cones and rods of the eye. The cones function for day light vision and color
perception whereas rods are sensitive to the quantity of light perceived. These stimuli are then
sent to the brain, where they are computed and interpreted as color. This complexity of color is
further modified by the embryonic development of the brain, aging process, aberrations of color
vision like color blindness, dichromatism, mental fatigue and drug intake.
The object
The quality of the color of an object (the tooth) depends on its ability to absorb, reflect,
transmit or refract the light energy falling on it. The surrounding environment greatly influences
the color. The ceiling and the walls reflect light and should not be pained in bright colors.
Neutral colors like grey or white should be selected.
Contrast effects
Smile designThe background considerably affects the perception of color. Different contrasts effects
that alter the color vision should be understood.
Simultaneous contrast
Is visualized when two objects are viewed at the same time. The light or dark contrast
can be correlated to the surrounding environment like skin tone, hair color and brightness of
adjacent soft tissues and teeth. Hence, brighter shades should be chosen for light toned patients
and darker shades for pigment toned patients
.
Actual contrast
Is influenced by the size and the chroma of the tooth. A brighter tooth looks larger while
a darker tooth of the same dimension look smaller.
Shade selection
Shade selection is a complex procedure due to the variations and differences in the
optical properties of the new generation of cosmetic restoration materials. It can be well
accomplished by understanding the fundamentals of color and adopting a proper methodology of
matching shades. The effective communication with the laboratory and precise fabrication and
meticulous finishing of the restoration will affect the color of the final restoration.
Shade selection sequence
Any color modification procedures like bleaching or microabrasion should precede color
selection after ensuring color stabilization.
Smile design Make the shade selection at the beginning of the procedure as well as over different
appointments (diagnosis, prophylaxis etc.)and cross check these observations.
View the patients at eye-level. The operator should stand between the light source and the
patient.
In a contrasting environment, colors look more intense and brighter. Hence it is wise to
ask the patient’s to remove artificial lip color.
Place the tabs as close as possible to the area that is being checked.
Moisten the tab and eliminate the worst match.
Evaluate the value (upper to lower). Value is the most important factor in shade
matching. If the value blends, small variation in hue and chroma will not be noticeable. The
value is to be matched with eyes half closed.
After value, mark the translucency
Match the chroma (more or less saturated) and finally, hue in that order.
To avoid hue sensitivity, rapid observation is made for 5 seconds (not more than 20 seconds).
Look away; ideally stare at a blue surface, which will readapt the vision to the orange yellow
portion of the spectrum.
Match prior to tooth preparation, since preparation dehydrates and changes color due to the
debris of preparation.
Match the tab with the opposing tooth also.
Metamerism complicates color matching, as the tabs look different under different light sources.
The best approach is to use three light sources; cool white fluorescent light, incandescent
operatory lamp and day light if possible.
When in doubt, always select higher value and lower chroma, since it is easy to lower value and
increase chroma
Smile design Shade tabs of different batches don’t always match; hence it is wise to send the actual
selected shade tab to the technician.
Make a decision regarding relative translucency, area of hypo calcification, increase
saturation, crack lines surface texture and other characterization. Make a drawing of the facial
surface and record all patient information graphically.
DENTAL BLEACHING
Bleaching is one of the most commonly sought elective dental procedures to brighten a smile. It
is a simple, fast and effective treatment to change darker tooth shades into lighter ones.
Chemistry of bleaching
Bleaching process is based on the oxidation of bleaching agent. Oxidation is the
chemical process by which organic materials are converted into carbon dioxide and water. The
oxidation reduction reaction that takes place in the bleaching process is called the redox reaction.
Bleaching slowly transforms the organic substance in the stained tooth into chemical
intermediates that are lighter in color than the original tooth shade. In a redox reaction the
perioxide (oxidizing agent) has free radicals with unpaired electrons, which it gives up,
becoming reduced. The stained tooth structures accept these electrons and becomes and
oxidized, thereby reducing the organic colorants. The free radicals produced by the peroxides
are perhydroxyl and nascent oxygen. Of these, the perhydroxyl is a more potent free radical
which is responsible for a better bleaching action.
In order to promote the formation of perhydroxyl radicals, the peroxide is buffered to a pH range
of 9.5 to 10.8. The buffering provides a greater amount of perhydroxl radicals, which results in a
better bleaching effect.
Smile designThe most common bleaching materials used are hydrogen and carbamide peroxide.
Carbamide peroxide first breaks down into hydrogen peroxide which then further liberates the
above mentioned free radicals. Unlike the hydrogen peroxide, the carbamide peroxide bleaching
agent must remain in contact with the teeth for a longer period of time to obtain complete
efficiency of the reaction. Carbamide peroixde is less irritating to the gingival tissues thus better
tolerated by the patients when used as a home bleaching agent.
Mechanism of bleaching
In the presence of moisture as well as surface debris on the tooth, the ionization by
hydrogen peroxide occurs by decomposition into water and nascent oxygen which is a weak
radical making the peroxide which is a weak radical making the peroxide inefficient as a
bleaching agent. Hence, it is important to have teeth dry and free of surface.
Increase in the temperature, higher peroxide concentration and the duration of exposure
of the tooth structure to the peroxide within the oxidation process leading to a greater degree of
color change.
Saturation Point
Prolonged used of a bleaching agent causes the whitening action to slowdown beyond a
point during the treatment. This is the saturation point. The bleaching if allowed to continue,
begins to break the inorganic structure from the enamel becomes rapid. Bleaching should thus
be stopped at or before the saturation point.
If bleaching is done beyond the saturation point, it clinically manifests an increase in
porosity on the tooth surface. A fluoride application is recommended and no bleaching agents
should be applied allowing the enamel to remineralise.
Smile design
Procedure for bleaching
Use of concentrated heroine or carbamide peroxide solution available in standard 35%
concentrations. In a technique described as ‘assisted office technique’, 35% carbamide peroxide
is tray loaded for 45 minutes, after following required protocols. Some bleaching materials are
available in a combination of a hydrogen peroxide and carbamide peroxide in 20% and 16%
concentrations respectively.
Preparation of trays
The bleaching procedure is recommended for the number of teeth seen in the patients
active smile. 1 millimeter reservoir for the bleaching gel. On the modified cast soft and clear
vacuuform matrix of 0.035”thickness is made. The matrix, carefully trimmed to cover only the
clinical crowns. Contact of the bleaching gel with marginal gingiva may result in tissue irritation
hence vacuuform trays should have a marginal seal to eliminate contact of the caustic bleaching
gel with the gingiva.
Isolation of teeth
Proper isolation of area with cotton rolls or rubber dam is mandatory. The gingival
surface is wiped and dried sufficiently.
Smile design
Etching of tooth surface
Each tooth is etched on labial surface for 10 to 20 seconds using 32% - 37%
orthophosphoric acid. This step removes any superficial surface stains and enhances the
penetration of the bleaching solution into the tooth surface producing a greater stain reduction.
Excessive etching causes the demineralization of the enamel matrix, leading to surface
irregularities and causing sensitivity.
Application of bleaching material
The bleaching materials is slowly loaded in to the vacuufrom trays so that it spreads all
over the labial surface of the teeth to be bleached. The trays are kept in place for an average
duration of 30 minutes depending on the type of material used and the manufactures
recommendations.
Micro-finishing and polishing
Following bleaching, the teeth are micro-finished using fine abrasive disks. Final
polishing is done with aluminum oxide or fine grit diamond.
Office bleaching of non vital teeth
The two most commonly used agents for bleaching of non-vital teeth are hydrogen
peroxide and sodium perborate.
Home bleaching
Smile designBleaching may be carried out at home by the patient. The home bleach technique
involves the application of bleaching agent through the use of vacuuform trays. The frequently
used bleaching agent is 10% - 15% carbamide peroxide.
Bleaching in relation to bonded restorations
It was determined in clinical studies that the bond strength of composite to enamel is
reduced when the tooth is bleached. The primary cause for the reduced bond strength is the
presence of the residual peroxide or oxygen, which interferes with the polymerization of resin
bonding systems and restorative materials. Any bonded restorations in the bleached teeth need
to be done after a period of two weeks.
Enamel microabrasion
Hydrochloric acid *18%) pumice abrasion can remove white enamel opacifiers, multicolored
defects and many brown, orange, yellow enamel spots and streaks, regardless of etiology. These
stains can be eliminated with insignificant enamel loss if the stain is limited to a thin layer of
tooth surface (approx. 0.5mm). This procedure can be used independently or prior to bleaching
to give optimal results.
Management of Fluorosis stained teeth
A solution of anaesthetic ether, hydrochloric acid and hydrogen peroxide may also be
used for bleaching teeth with fluorosis stains. The anaesthetic ether removes surfaces debris, the
hydrochloric acid etches enamel and hydrogen peroxide bleaches it.
ESTHETICS WITH COMPOSITES
Smile design
Considerations in preparation design for anterior teeth.
The preparation design for anterior composite restorations should encompass elimination
of decay, function and longevity, and esthetic predictability.
Function and longevity
A pre-operative analysis of the occlusion is crucial to determine the palatal extensions
and the acceptable length in upper anterior restorations.
Checking the lateral and protrusive excursions will give an idea as to how far palatally the final
restoration can be placed. Researchers have found that a minimum of 1.5mm – 2mm of the
composite thickness is essential to give sufficient strength to the material. A conscious effort has
to be made to leave at least 2 mm of composite thickness at the margins for good marginal
adaptation and retention in larger restorations.
Esthetic predictability
After elimination of the decay and determining the extent of preparation required for
function and longevity, the preparations are evaluated and if required redefined. The preparation
design is extended to allow a smooth transition of shade from the composite restoration to the
rest of the tooth. This enables the restorations to achieve esthetic excellence.
To create proper tooth from, shape, shade and texture, and to optimize function, all cavity
preparations designs should have extension for function and esthetics (EFE).
The EFE ensures that the margin of the restoration overlays the defects. The esthetic advantages
are :
Successful masking of the defect
Better marginal adaptation
Smile design Natural transition of shade between composite and tooth
Ease of finishing and texturing
EFE and placement of composite for malaligned teeth
The preparation in mal aligned teeth is a typical and depends upon the degree of rotation
and angulation exhibited by the teeth and hence a uniform layer of composite cannot be placed to
treat such teeth. The effective use of opaque composites in areas having no tooth or thin palatal
structure, improves the blending of the restoration. Creating surface characteristics and
effectively placing the transitional angles on the facial surface can help to over come deficiency
in tooth reduction.
EFE and placement of composite for closing spaces
Diastema may be manifested to due to microdontia, discrepancy between tooth size and
the available ridge and also due to variation in the tooth morphology. Although some natural
spaces may be esthetically and phonetically acceptable, others are not and need corrective
restorative procedures. However, in cases where the size of the teeth is normal and a diastema
still exists, restorative creations using principles of illusion is recommended.
When a diastema is small up to 2mm, no tooth preparations is required. The minimal thickness
of composite can be adequately shaped especially at the cervical region to allow good
maintenance. However, in cases of a moderate diastema between 2-4mm the EFE should be
given on the proximal curvature of the labial surface of the tooth. The extension preparation is
close to the gingival margin and follows the contour of the inter dental papilla to end on the
palato-proximal line angle. The preparation is in the form of a depression, which provides a
definite stop and is done with a chamfer bur.
Smile designThe preparation design ensures adaptation of sufficient bulk of the composite at the gingival
margin creating contours favorable for gingival health. The labial extension allows smooth
blending at the composite tooth interface while the palatal extension provides stability and
retention. In cases with diastema larger than 4mm a similar preparation coupled with
recontouring of the other proximal surface of the tooth to maintain tooth proportions and form
may be required.
Diastemata are filed in one tooth at a time. A celluloid matrix is effectively used to get the
desired contour
EFE and placement of composites in cervical defects
Cervical defects are caused due to caries, abrasion, erosion or abfraction and a
combination thereof. Although management of these defects involves similar procedures, their
proximity to the gingiva makes it difficult to restore. Before any preparation, a gingival cord is
placed in the sulcus to allow a proper access to the defect and to keep away sulcular fluid or
blood from the cavity margins. Since bond strengths with the cementum are weak, no additional
bevel is recommended at the cervical region in cases where the base is in the cementum.
Smile designA round bur is used to roughen the surface of the cavity and a long bevel is placed on the
occlusal edge of the cavity. After etching, the cord ischanged and bonding adhesive is applied
followed by flowable composite which is used as an intermediate layer. The gingival cord is
removed after completion of the filling to facilitate finishing and polishing. The occlusion is
adjusted, especially eccentric contracts, to take care of primary or secondary abfractions. Fine
diamonds or carbides are used to finish the margins.
Tissue management
Success of composite restorations depends not only on preparation design, bonding
procedures, and quality of restorative material and skill of the dentist but it also largely
dependent on the thoroughness of the isolation. The greatest challenge involved in creating
predictable composite restorations near the gingival margins is to achieve hemostasis and control
of sulcular fluid. Therefore, tissue management becomes an integral element of these
procedures.
In case of contamination of composite by blood, blood pigments containing iron or ferric
sulphate migrate between the composite and tooth surface or between different layers of
composite. These pigments turn dark and are visible as a black-brown discoloration in the
restorations. Salivary contamination as well as crevicular fluid ingress in the preparation can
cause bonding failure
s at these areas leading to the failure of the restoration.
Retraction cords displace the gingiva and keep blood and suclurlar fluid away allowing proper
access with contamination during placement and finishing of composites. In cases where the
cavity design is close to the gingival margin, double retraction technique can be effectively used.
Smile designAstringent impregnated cords should be used with caution as nay residual astringent can
potentially contaminate the tooth s to be bonded causing a bonding failure.
Shade matching
Shade selection is done following standard protocol with references to the incisal third,
middle third and the cervical third of the tooth. The uniqueness of composites permits pilot
shade test to reconfirm shade attributes before final restorations. The pilot shade test is carried
out using a selected shade in a bulk of 1.5mm- 2mmon the involved tooth and a contra lateral or
guide tooth. The composite is then cured and finished and the accuracy of the shade match is
confirmed. Any changes in the value, transluency and chroma are recorded and the shade is
changed if required.
Three procedural steps for finishing and polishing
Gross reduction, contouring, defining the margins. Fine grit diamond abrasive or tungsten
carbide finishing bur can be used for the these purposes (100µm size abrasives)
Intermediate finishing is used to reduce scratches left by gross reduction and to blend all
surfaces with each another keeping the orientation of various facial planes intact (less than
100µm but morethan 15-20 µm particle size).
Final abrasive polishing imparts enamel like effect on the restorations. Loose abrasive
devices, disks, pastes with particle size less than 20µm is used.
ESTHETICS WITH CERAMICS
Ceramics laminate veneers
Smile designIn 1930 Charles Pincus used a unique procedure to improve the smiles of certain Holly
wood actors. This technique was non-invasive and gave good esthetic results with resin and air
fired ceramics. But the veneer coping made then lacked permanent retention and later this
technique was discontinued.
Considerations in tooth preparations for ceramic laminates
Tooth preparation design will depend upon the existing color of the teeth, whether change
in alignment or an increase in height of the final restoration is sought. When a mild to
moderate discoloration has to be masked the preparation can be minimal from 0.3mm cervicaly
to 0.5mm at the incisal edge. Whenever a severe discoloration has to be masked the preparation
has to be deeper to allow more die spacer to be applied on the model. His excessive space allows
use of resin curing cement to mask the severe discoloration. Adding more opaque ceramic in the
veneer will mask undesirable tooth color but will limit the display of vitality.
A more translucent ceramic will allow more light transmission and reflection internally making
the restoration more vital. If change in alignment is indicated then more preparation will be
required in certain areas. When length of the veneer has to be increased a palatal extension is
recommended.
Preparation of maxillary teeth for ceramic laminates
Mock preparation on the pre-operative casts and diagnostic wax up gives valuable
information about he amount of tooth preparation and helps to visualize the end result.
Local anesthesia may be required when the preparations reaches the dentin and to
facilitate easy gingival retraction procedures.
Self-limiting three-tiered depth cutting burs of known dimensions (0.3mm and 0.5mm)
facilitate repaid, adequate and conservative tooth reduction. The depth roves are made by
Smile designmoving them on the facial surface from the mesial to the distal and by changing the angle of the
bur to facilitate their orientation in two planes (Fig. 8-1a). Then the facial reduction is achieved
following the labial contour of the tooth till the depth grooves. Besides, the contra-lateral tooth
can be used as a reference to check adequate tooth preparation. Selective labial tooth preparation
is required to create a favorable arch form.
A modified chamfer margin is preferred to allow distinguishable finish line in the
impression, definite seat and adequate bulk for laminates. The margin is usually supra-gingival
or equip-gingival. The margin is taken intra-crevicularly in certain cases to mask the underlying
discolored tooth and cover cervical lesions.
The proximal finish line is placed into the embrasure area to ensure that the margin
between the laminate and the unprepared tooth structure is well hidden. Deficient preparation
reveals unaesthetic margins proximally.
Incisal preparation depends on whether an increase in tooth height is required or not. In
case where the increase in not sought, the incisal preparation ends midway between the labio-
lingual width of the incisal edge. In case when the length of incisor is to be increased, the incisal
table is flattened with a bevel of 45o palatally. The palatal preparation is a wrap-around design
with the margin placed inferior or superior but never at the contact of the mandibular incisor in
centric occlusion
Similarly, window preparations are advocated for canines and premolars when increase in
height in not required.
When the length has to be increased, the anterior and lateral guidance has to be considered
and appropriate tooth preparations has to be carried out to allow for adequate thickness of the
laminate at the incisal or occlusal area.
Smile designTry in
Chair side try-in is done to check individuals veneer fit, collective fit of veneers and the
shade of the composite luting cement that should be used to get the desired final result.
Individual veneer is tried for marginal fit, adaptation and retention. Any premature
contacts are relieved at this stage. The veneers should fit in passively with good contacts and not
actively as it may lead to displacement of some veneers.
After Cementation
The patient is viewed periodically for the gingival response and maintenance regimen.
Usually a 3month check up followed by a 6 monthly check up is recommended.
Metal ceramic and all-ceramic restorations
Metal ceramic and all ceramic restorations have excellent esthetic potential.The metal
ceramic restorations owe their popularity to the simplicity of bridge construction, durability,
strength, marginal adaptation and versatility of use.
Can be used successfully for various complex clinical situations like long span bridges, full
mouth rehabilitation as also a number of semi-fixed type of appliances.
All ceramic restorations are characterized with a dentin like core which makes it possible
to mimic the translucency of natural teeth. They are bio-compatible with the gingival tissues
and exhibit excellent marginal fit. All ceramic restorations are indicated for crowns, veneers,
inlays, onlays and three unit bridges with the premolar as the distal most abutment.
Although all anterior teeth were esthetics is a prime concern can be indicated for all ceramic
restorations, caution has to be taken when a para-function, exists, when tooth structure is
insufficient to support the ceramic, in short clinical crowns and when the lingual preparations is
Smile designthinner than 0.8mm. In such cases a metal ceramic restorations is functionally stable and
indicated.
Imperatives of tooth preparations
Length and taper of the preparation for retention and resistance.
Enough reduction to allow thickness of the ceramic for excellent esthetics.
Occlusal clearance for occlusal function and anterior guidance.
Tooth preparations for metal ceramic crowns.
The incisal edge reduction of 1.5mm – 1.8mm and the occlusal reduction of 1.5mm –
1.7mm with functional bevel is recommended . Reduction is achieved by using a wheel diamond
on the incisal edge or a round diamond of known diameter in the occlusal grooves. The incisal
edge reduction is followed by the labial reduction. When reducing the labial surface of the tooth,
the exact contour must be emulated. This helps to prevent excess removal of tooth structure
which may lead to deficient lingual wall preparation especially at the incisal aspect. The labial
reduction is achieved in two planes with a round-ended tapered bur, the first orientation involves
the incisal two thirds of the tooth.
The palatal reduction is carried out allowing sufficient space for the crown and to re-
establish normal occlusal and protrusive relationships. A pear shaped or rugby diamond is used
to reduce the lingual concavity while the rest of the cingulum surface is reduced with a round
ended tapered diamond bur.
The proximal reduction involves smooth movements from the labial surface to the palatal
allowing is finished margin on the proximal surface. Long tapered fissures can be initially used
followed by round ended fissure burs to achieve desired reduction. Preparations must include
Smile design1mmm peripheral shoulder or chamfer with bevel for ceramometal crowns. The objectives are to
achieve a convergence angle of the axial walls in the range of 6 to 10 degrees.
A shoulder with a 90 degrees cavo-surface angle or a stopping shoulder of 120 degrees is
recommended for a adequate support of porcelain. When the metal margin is shortened for
esthetic reasons, shoulder porcelain requires 1.2mm of tooth reduction at the margin. The
shoulder with a long bevel is advocated for improved marginal fit but it cannot be
accommodated in shallow gingival sulcus. Hence short bevel of 0.5mm with a cavo-surface
angle of 135 degrees is preferred.
Chamfer (0.5mm) is the finish line of choice for metal backing. For porcelain fused to
metal backing, a metal collar on a modified chamfer is preferred. The palatal chamfer is blended
smoothly with the labial shoulder lingual to the contact area for good esthetic results. All sharp
line angles within the preparation should be rounded to reduced stress concentration.
Tooth Preparation for all ceramic crowns.
Although the preparation sequence for all ceramic restorations is similar to the metal
ceramic one, the main concern for the dentist in the preparation for the all ceramic crowns should
be to minimize the stresses that could be incorporated on the ceramic in function.
The length of the preparations is important as load applied from a lingual direction on
short preparations can lead to severe compression of the labial shoulder leading to a fracture.
The incisal edge is reduced to get flat area however a reduction in excess of 3mm is avoided. In
some cases a reduction of up to one third of the crown height may be required to get rid of the
thin incisal edge. The facial reduction is achieved in two planes at a depth of 1mm to 1.5mm.
The lingual aspect should be shaped to remove any uneven surface or sharp line angles and
should incorporeated or sharp line angles and should incorporate a definite lingual concavity
Smile designwith a high lingual axial wall whenever the cingulum prominence and occlusion is favorable.
Lingual depth should be 1mm – 1.5mm and should not be less than 0.8 mm. The proximal
preparation is completed with a taper of 6o-8o and will help in one path insertion. Excessive
taper will cause inadvertent forces on the ceramic and leads to reduction in flexural strength.
The facial reduction, lingual reduction and the proximal reduction should end into a well defined
shoulder.The shoulder should not create any undercuts for the restorations and hence any angle
in excess of 90o should be avoided. The shoulder should not necessarily be uniform labially,
proximally and lingually, as excessive reduction may be required to do so, compromising on the
resistance and retention form of the preparation. The shoulder is usually 0.8mm – 1.0mm wide
in the labial and lingual and 0.5mm – 0.6mm in the proximal aspect where the ceramic flares to
give sufficient strength. The smooth finish line should not be steep inter proximally but have a
smother gradient to avoid potential stress area during function.
As compared to the preparation for metal ceramic restorations, the finish line for all ceramic
restorations should be a shoulder which is at right angles to the direction of stress thus increasing
the fracture resistance. In the final preparation all sharp line angles and undercuts are avoided
providing maximum strength and resistance. Adequate length of the preparation is required in
order to counter the tipping forces and increase the surface area for additional retention.
The depth of the facial and lingual shoulder should be 1.0mm (with a minimum of 0.8
mm) and interproximally the shoulder can be 0.5mm as the restoration flares interproximally. A
taper of 5o - 10o is advisable for conservity and increased support to the restoration. Increased
taper leads to stress concentration in areas where the support is lacking.
Try-in
All metal castings are evaluated for margin integrity, internal fit, stability and adequate
space for ceramic material. Intra occlusal relationship record is needed in extensive rehabilitation
cases. Bisque trials for ceramic restorations are assessed for location, site and tightness of
Smile designproximal contacts, marginal adaptation and favorable centric and eccentric occlusal contact
without interferences. Besides the shape, contours and color; adequate surface characterization is
checked and incorporated.
The trial for all ceramic restorations are assessed for a passive fit, margins, proximal
contacts, stability, shade, form, characterization and occlusion.
IMPLANT – ESTHETICS
Pre-implant esthetic consideration
In cases of anterior implants in the esthetic zone, certain specific esthetics criteria have to
be considered. When esthetics is the prime reason for seeking implant prosthetic treatment, the
patient’s upper lip line will be of extreme importance for the planning of the definitive
superstructure. In patients with a high lip line or requiring upper lip support from the prosthesis
a removable over denture will more likely fulfill the demands of function and esthetics than an
implant borne bridge construction.
The single tooth anterior implant situations are of great concern as the esthetic requirements and
expectations have to be properly balanced keeping in mind anticipated post-surgical results. The
dentist should analyze anterior single tooth implant situations considering the adjacent teeth,
contra-lateral tooth, probable emergence profile and presence or absence of inter dental papilla
when ever the active smile exposes enough of gingival tissues.
There are many limitations and contra indications specific to the maxillary single tooth implant
apart from the routine contra indications associated with implant therapy. The common causes of
a missing maxillary tooth are traumatic loss, root fracture, agenesis and periodontal disease. All
these leave some deficiency in the facial bone over the root of the missing tooth. Majority of the
cases of maxillary single tooth implant in patients with high upper lip line require bone grafting
Smile designfor ideal esthetics while in some cases bone grafting would be necessary to provide adequate
healthy peri-implant soft tissue to maintain optimal hygiene in the cervical region.
Apart from the inadvertent deficiencies in the facial bone associated with various clinical
situations, the soft tissue form also plays a major role in the esthetic outcome of single tooth
implants.
In 1989, Misch reported 5 prosthetic options available in implant dentistry. The first
three options are fixed prosthesis (FP). The next two options are removable prostheses (RP).
Prosthodontic classification
FP – 1 Fixed Prostheses, replaces only the crown, looks like a natural tooth.
FP – 2 Fixed Prostheses, replaces the crown and a portion of the root; crown contour appears
normal in the occlusal half but is elongated or hyper contoured in the gingival half.
FP – 3Fixed Prostheses; replaces missing crowns and gingival color and portion of the
edentulous site; prostheses. Most often uses denture teeth and acrylic gingiva, but may be
porcelain to metal.
RP – 4 Removable prostheses; over denture supported completely by implant.
RP – 5 Removable Prostheses; over denture supported by both soft tissue and implant.
Fixed Prostheses
Smile designFP-1 is a fixed restoration and appears to the patient to replace only the anatomic crowns of the
missing natural teeth. There usually has been minimal loss of hard and soft tissues. The final
restorations appears very similar in size and contour to most traditional fixed prostheses used to
restore or replace natural crowns of teeth.
FP –1 prosthesis is most often desired in the maxillary anterior region. However the width and /
or the height of the crestal bone is frequently lacking, augmentation is often required before
implant placement to achieve a natural looking crown in the cervical region because there are no
inter dental papillae in edentulous ridges, gingivoplasty is required after the abutment is
positioned to improve the interproximal gingival contours. Ignoring this step causes open “back”
triangular spaces (where papillae should usually be present) when the patient smiles. The bone
loss and lack of inter dental soft tissue complicates the final esthetic results, especially in the
cervical regions of the crowns.
FP-2 fixed prosthesis restores the anatomic crown and a portion of the root of the natural tooth.
The volume and topography of the available bone dictate a deficient vertical implant placement
compared with the FP-1 prosthesis, which is more apical compared with the cemento-enamel
function of a natural root. As a result the incisal edge is in the correct position, but the gingival
third of the crown is over extended, usually apical and lingual to the position of the original
tooth. If the high lip line during smiling or low lip line during speech are favorable and do not
display the cervical regions, the longer teeth are usually of no consequence. FP-2 prosthesis that
is not hidden by lip position during smiling or speech can be solved by using a removable soft
tissue replacement device.
Smile designThe FP-3 is a fixed restoration that appears to replace the natural teeth crowns and a portion of
the soft tissue. As with the FP-2 prosthesis, the original available bone height loss decreased by
natural resorption or osteoplasty at the time of implant placement. To place the incisal edge of
the teeth in proper position for esthetics, function, lip support and speech, the excessive vertical
dimension to be restored required teeth that are unnatural in length. The patient having high
maxillary lip line during smiling and low mandibular lip during speech will display the longer
teeth which look unnatural. In the AP 3 the restored gingival colour and contour give the teeth a
more natural appearance in size and shape and mimic the inter dental papilla region. The
addition of gingival tone acrylic or porcelain for a more natural appearance is often indicated.
RP-4
It is a removable prosthesis completely supported by implants and or teeth. It may draw
the same appearance as an FP-1, FP-2, FP-3 restorations.
RP –5
It is a removable prosthesis combining implant and soft tissue support. The prosthesis is very
similar to traditional over denture.
Factors for favorable implant placement
The physiologic limits with in which the implant can be placed are governed by the
following
The space between implant and periodontal ligament of the adjacent tooth should be
1mm.
The average width of periodontal ligament is 0.25mm.
Smile designThese natural periodontal components will require a space of 1.25mm on either side of the
implant. Thus, mesio-distally the implant diameter is added to this minimum space required.
The facio-lingual requirement. For a 3.5mm implant placed in the anterior region a minimum of
6mm of space mesio-distally has to exits to accommodate all related components. Ideally, the
ridge should be 5-6mm wide labio lingually, to allow at least 1 mm of the cortical bone labially
and lingually. However, to impart esthetics in the inter dental papilla region, the distance
between an implant and natural teeth is kept 2mm.
The implant should be 3mm apical to the gingival margins of the adjacent teeth.
Labio-lingual orientation of the implants helps to achieve desired emergences profile.
Placing the implant slightly palatally helps the dentist to build up a proper emergence profile to
the crown.
To obtain satisfactory peri-implant gingival morphology, tissue volume should be 20-
25% more than the estimated need to allow adaptation of gingiva to the prosthetic reconstruction.
Wider diameter implant will ease the transition of the implant head to the artificial crown as it
emerges from its soft tissue housing. The wider diameter implants will not be required to be
placed far apical to the cemento-enamel junction of the adjacent tooth. Immediate implants help
to preserve the hard and soft tissues, and maintain the emergence profile as in natural teeth.
PERIO – ESTHETICS
Esthetic periodontal considerations:
Shape and position of the gingiva:
In an ideal esthetic relationship, the position of the gingival margin is dictated by the
vertical limits of the active smile, the gingival margins of the maxillary central incisors and
canines positioned at the vermilion border of the upper lip. The gingival margin of the lateral
Smile designincisors is usually located 1 to 2 mm more incisally or at the same height of the central incisors
and canines.
The gingival zenith is distal to the long axis of the tooth for both the maxillary central
incisor and canine while it is situated on the long axis of the tooth for the maxillary lateral
incisors.
The gingival height of contour of the premolars and molars lies in a more occlusal position as it
moves posteriorly.
The horizontal limits as well as the vertical limits of the smile should be evaluated. Most
patients show the maxillary teeth with or without the gingiva upto the first molar in an active
smile. To provide for proper depth and harmony of the smile, the gingival display should be
consistent and proportional from tooth to tooth, from the left first molar to the right first molar.
Embrasures
In healthy periodontium the inter dental papilla blends into embrasure spaces completely
from buccal to lingual which is an important esthetic factor assuring harmony in the dental
composition. However, in cases of recession or post-periodontal therapy the embrasures may
open up revealing a black triangle.
Biologic width
It has been demonstrated fro autopsy recordings that the mean sulcus depth is 0.69mm,
mean length of the junctional epithelium is 0.97mm and connective attachment is 1.07mm; the
combined width of the latter two is 2.04 mm and is called the ‘biologic width’. This biologic
width is always present, therefore restorative margins must maintain a distance from the alveolar
crest that respects the biologic width, otherwise gingival recession or pocket formation ensues.
Esthetic periodontal defects and its correction
Smile design Periodontal defects posing an esthetic problem.
May include :
Violations of biologic width
Gingival asymmetries
Excessively gingival display
Localized gingival recessions
Deficient pontic areas
Abnormal frena.
Excessive gingival pigmentation
Inadequate interproximal papilla
Restorations which are over extended in the cervical region should be carefully removed and
proper cleaning of the teeth is recommended with excavation of deep carious lesions in the
cervical region. Provisional restorations should then be fabricated with proper contouring in the
cervical region. The pockets should be probed and isolated areas of excessive bone loss should
be marked and regenerative procedures instituted.
Surgical technique for establishing proper biologic width involves recontouring the
osseous crest so that a minimum of 3 mm of the flap can be placed coronal to the position of the
recontoured osseous crest. This will take into consideration the average biologic width of 2mm.
In accidental tooth fractures or any other clinical situations where the restorative margins may
violate the biologic width, bone removal in the adjacent teeth might be necessary to get desired
esthetic result.
Gingival asymmetries
Smile designWhenever the facial gingiva of the anterior teeth does not follow a symmetrical pattern,
crown length discrepancies are perceived; some teeth appear longer while others appear shorter.
Correcting these discrepancies to an esthetic gingival pattern becomes the main goal of the
esthetic or restorative dentist.
The possible causes of gingival asymmetries are :
Gingival hyperplasia
Altered passive eruption
Tooth or teeth malpositioning
Over zealous tooth brushing
Periodontal disease
Esthetic crown lengthening
When a disparity in the clinical crown length exits between contra lateral teeth resulting
in a left/right side height discrepancy, esthetic surgical correction can be provided to enhance the
cosmetic result before restorative measures.
functional crown lengthening
In such cases ‘esthetic crown lengthening’ may be carried out by performing gingivectomy and
or osseous resection only on the facial aspect, for better esthetics. Root exposure is often a
common complications and intentional root canal or post surgical treatment with veneers or
crowns may be required.
Excessive gingival display (gummy smile)
Smile designA gingival display of more than 3mm in active or moderate smile may be termed
“gummy”. Excessive gingival display or gummy smile can be caused by any of three factors.
The causes include:
Maxillary over growth
Tooth malposition
Delayed apical migration of the gingival margin or altered passive eruption.
Crown lengthening procedures can correct the latter two defects. Usually a surgical and
orthodontic correction may be needed in these cases.
Deficiencies in edentulous ridges
Deficiencies in edentulous ridges could be bucco-lingual, apico-coronal or a combination
of tooth. These deficiencies can lead to functional as well as esthetic compromises for
prosthodontic and implant related treatments.
Several surgical techniques have been devised to restore the contour of edentulous ridges
that have been altered by disease or trauma before adaptation of pontics. The most commonly
used classification is as follows:
Class I: Bucco-lingual loss of tissue with normal ridge height in an apico-coronal
direction.
Class II: Apico-coronal loss of tissue with normal ridge width in a bucco-lingual direction.
Class III: Combination of bucco-lingual and apico-coronal loss of tissue resulting in a loss
of normal ridge height and width.
Correction of class I type of defects
Smile designBucco-lingually edentulous ridge defects are the most commonly encountered and most
predictably treated of all alveolar ridge defects. Surgical procedures such as inter positional
grafts of hydroxyapatite or connective tissue are ideal for augmentation for such type of defects.
For connective tissue grafting, the donor site selected is usually the one with the thickest
available connective tissue, such as maxillary tuberosity. Augmenting the edentulous ridge at
the time of surgery slightly more than necessary will compensate for the shrinkage that occurs
during surgical healing.
Correction of class II defects
These are more difficult to treat predictably and are usually corrected with onlay grafts.
Slight defects in any plane of space can be treated. Usually in one stage while moderate to severe
type of defects often require multiple procedures with an interval of 6 to 8 weeks post
operatively.
Correction of class III defects
This is the most difficult type of defect to manage and generally requires multiple
surgical procedures. Palatal donor sites fill in totally within 4-8 weeks and can again serve as
donor sites, if necessary. When multiple procedures are anticipated the bucco-lingual dimension
is generally recaptured first, this sequence provides a broader base (more vasularity) for the on
lay graft.
The provisional restoration design is of crucial importance to maneuver the soft tissues covering
the ridge. For esthetically pleasing restorations various pontic design are used; however much
has been spoken about the ovate pontic. The ovate pontic is highly convex and sits well within
the confines of the alveolar ridge. The ovate pontic contacts the alveolar ridge in a depressed
Smile designarea, which helps to create good emergence profile for the pontic. However, this pontic is very
difficult for the patient to maintain.
Abnormal frenal treatment
For diastema closure. A resection (frenectomy) or a repositioning (frenotomy) may be
necessary. Whenever there is excessive pressure caused by the frenum, then a frenectomy may
be the best procedure, however when esthetics is the only factor then a frenotomy may be
necessary to give the desired result.
Excessive gingival pigmentation
Skin tone, texture and color differ in races, and different regions the color of the human
gingiva also differs, usually pink with certain areas showing a diffuse pigmentation. Gingival
pigmentation is due to the deposition of melanin pigments in the basal layer of the mucosa. In
mammals it is brown, black or blue black.
The saturation of these pigments causes an unesthetic dark or gingival display. In people
with fair skin and high lip lines. The pigmentation usually occurs in diffuse patches; some times
a continuous area is seen.
The surgery can be performed under local anesthesia with the following techniques.
Gingivo-abrasion technique
Smile design Split thickness epithelial excision
Combination technique which involves gingivo-abrasion and split thickness epithelial
excision.
Gingivo-abrasion technique
A medium grit foot ball shaped diamond bur is used at high speeds on the epithelium to
denude it. Care should be taken not to abrade the periosteum.
A periodontal pack is the placed over the denuded epithelium.
Split thickness epithelial excision technique
A split thickness island of epithelium is removed on the attached part of the
mucosa.
A periodontal pack is then placed and left for a week.
Smile design
Combination technique
In cases where pigments are present very close to the marginal gingiva and where the
gingival pattern as areas of depression and elevations on the facial aspect, a combination
technique is advised. Gingivo-abrasion is used near the marginal gingiva and areas where a split
excision of difficult.
Open inter proximal spaces.:-
The inter dental gingival occupies the gingival embrasure which is the inter proximal
space beneath the area of tooth contact. The shape of the gingival in a given inter dental space
depends on the contact point between the two adjacent teeth and the presence or absence of some
degree of recession. Open inter-proximal space may be caused due to diverging roots, abnormal
clinical crown shape and absence of inter proximal papilla. The first two can be corrected
orthodontically and by the reshaping of the clinical crown respectively. While the last is the most
difficult to manage. Because currently there are no predictable methods to regenerate the inter
proximal papilla.
ORTHO – ESTHETICS
Crown width discrepancy
Size of the teeth is one of the most important elements of anterior dental esthetics. Tooth
size discrepancy is commonly found in patients with peg shaped lateral incisors. Even after
getting the teeth perfectly aligned and the arch forms properly established with orthodontic
treatment, the abnormal shape and smaller size of lateral incisor poses an esthetic problem.
Smile design
It is therefore imperative to restore the size of the lateral incisors after the completion of
orthodontic treatment for good overall treatment result. To determine the space required to
restore the crown width, during the treatment planning stage, construction of a diagnostic wax up
in an important step to visualize the final result. After removal of the fixed orthodontic
appliances, restorative phase should be immediately started and provisional restorations should
be given before final restorations to avoid relapse.
Maxillary peg-shaped lateral incisors can be restored with ceramic veneers.
Proximal re-contouring
When the widths of the anterior teeth do not follow the golden proportions. Then the
larger teeth should be re-contoured to smaller size and the space thus created is effectively
utilized by the orthodontist to resolve the discrepancy. This procedure is usually done before
starting orthodontic treatment and care should be taken not to alter the morphology of the teeth
and the contact points.
Space gaining for a single tooth restorations
Loss of a tooth in the posterior segment can led to tipping and drifting of adjacent teeth,
poor inter proximal contacts, poor gingival contour, reduced inter radicular bone, and supra
eruption of unopposed teeth such a clinical situations becomes challenging to correct
orthodontically and restore prosthetically. In loss of the maxillary right second premolar led to
medial tipping and mesio-palatal rotation of the first molar. This resulted in reduction in the
pontic space. Large Nance palatal button was cemented for palatal anchorage to move the molar
distally.
Smile designSegmental stainless steel wire with compressed nitinol coil spring was placed between the first
molar and the premolar. The maxillary first molar was moved distally creating sufficient space
for the pontic. After provisional restorations the final restorations were placed.
Replacement of missing laterals with implants
Dental agenesis occurs quite frequently, especially of the maxillary lateral incisors, and it
presents true challenge for an esthetic solution.
The osseo-integrated implant is the most conservative and biological method, since the
missing tooth can be replaced without damaging neighboring teeth.
If the use of implants is the part of treatment plan for the missing lateral incisors, it is necessary
to decide the exact placement of implants, evaluate the smile line and gingival contour. When
the lateral incisors are missing, there is usually no adequate space to restore them due to drifting
of the adjacent teeth. In such cases, it is essentially to gain adequate space with orthodontic for
the placement of implant and crown restoration for good esthetic result. The exact amount of
space created should be according to the proposed size of lateral incisors, which should be
proportions to the width of the central incisors.
Before the orthodontic appliances are removed it is important to evaluate radiographically the
position of the roots of adjacent teeth. The roots of the central incisors and canines on either side
in case of bilaterally missing laterals should be parallel to each other with adequate space
between the roots for implant placement.
The minimum space of 6.5mm between adjacent roots is required to place a standard
implant of 3mmm width.
Impaired dento-facial esthetics and function due to absence of canines.
Smile designThe position of canines in all three planes of space is very important from esthetic and
functional point of view. The ectopic eruption and impaction of maxillary permanent canines is
a frequently encountered clinical problem.
The canines also provide the main gliding inclines for lateral excursions of the
mandible.Thereby providing the patient with a functional occlusion. Therefore, it is not only
important to get healthy favorably positioned impacted teeth into occlusion but also to position
them in such a way that they maintain the integrity of occlusion, provide good function and
optimal esthetics.
Establishing proper anterior guidance
As Angle (1907) stated that, “Each dental arch describes a graceful curve and that the
teeth in these arches are so arranged as to be in greatest harmony with their fellows in the same
arch, as well as those in the opposite arch. The sizes, forms, inter-digitating surfaces, and
positions of teeth in the arches are such as to give one another, singly and collectively, the
greatest possible support in all directions”.
Proper inter-incisal relationship is important to maintain the vertical position of incisors.
Loss of this relationship leads to supra-eruption of incisors and deep bite.
In severe deep bite case, there is often attrition of lower incisal edges and the palatal surfaces of
upper incisors, leading to shorter clinical crowns of the lower incisors and lack of anterior
guidance. In such a clinical situation, if there is any restoration in the maxillary anterior region,
it will have a tendency to de-bond due to lack of sufficient vertical clearance.
Therefore, it is necessary to establish proper anterior guidance with orthodontics so that
the palatal surfaces of upper anterior could provide a harmonious glide path for the lower
anterior teeth during the protrusive excursion of the mandible. These teeth should work against
Smile designone another to separate or disclude the posterior segments as soon as the mandible moves out of
centric closure.
Ortho-Perio –Restorative Perspective
An integrated orthodontic, periodontal and restorative treatment is useful in wide variety
of patients for improved occlusal relationships of teeth, proper gingival architecture and esthetic,
biologically sound restorations.
Abnormal gingival architecture
Color, contour and the health of the gingival tissues provide the framework and back –
drop for the esthetic smile.
During the process of eruption the whole periodontal apparatus is carried with the erupting tooth.
When there is asymmetric eruption of the teeth it will also result in discrepancies in heights of
the underlying crestal bone. This, in turn, results into asymmetries in gingival heights (gingival
zenith) from one side of the arch to the other. This type of a clinical situation can be managed
orthodontically by intrusion or extrusion of teeth.
REVIEW OF LITERATURE
Smile design
Van Zyl I, Geissberger M. (2001) describes a tool dentists can use to show patients potential
tooth sizes, shapes and arrangements before carrying out treatment. Simulated shape design, or
SSD, is a reversible method of demonstrating potential esthetic outcomes that involves creating
trial restoration shapes and placing them over a patient's teeth. SSD is a simple technique that
any dentist can perform. In essence, the technician makes new tooth shapes in wax, the dentist
places these in the patient's mouth and the patient evaluates them. The dentist then makes
modifications in the SSD, which he or she reports to the technician.so that Both the esthetic
(smile design) and functional elements (anterior guidance) of the restoration can be checked with
SSD. SSD could become the standard in determining whether or not to proceed with esthetic
treatment.
E M Narcisi, J A DiPerna (1999) highlights the harmonious integration of modern smile
design, material selection, and interdisciplinary communication that must be addressed in order
to deliver optimal treatment with porcelain laminate veneer and laboratory-fabricated resin inlay
restorations.
Morley J, Eubank J (2000) categorize macro-esthetic criteria based on two reference points: the
facial midline and the amount and position of tooth reveal. The facial midline is a critical
reference position for determining multiple design criteria. The amount and position of tooth
reveal in various views and lip configurations also provide valuable guidelines in determining
esthetic tooth positions and relationships. He concluded that Macro-esthetic components of teeth
and their relationship to each other can be influenced to produce more natural and esthetically
pleasing restorative care.
Smile design
Dorfman WM.(1995) stated that Even though many patients may simply let you choose a
smile style for them, once you select it, show it to them for their approval. As Jennifer de St.
Georges says, "Inform before you perform. No surprises!" On the other hand, when patients offer
verbal descriptions of how they want their smiles to look, there is a lot of room for subjective
interpretation. By using photographs and models, much of the confusion can be eliminated. After
all, our goal is to make the patient smile.
Messing MG (1995) concluded Successful cosmetic dental treatment is both functional and
aesthetic. It requires evaluation of a patient's expectations, diagnosis of pre-existing problems
and careful planning of treatment to eliminate or control the causes of existing conditions. The
use of mounted diagnostic casts and a diagnostic wax-up allows visualization of the expected
result. Provisional restorations offer a "dress rehearsal" to preview functional and aesthetic
results before completion of the final restorations. The term "smile architecture" is used to
describe the process that guides a patient and dentist from initial complaint through to final case
acceptance.
Singer BA. (1994) introduced to the literature a framework for understanding artistic
principles as they relate to clinical cosmetic dentistry, ie, shaping teeth and creating illusions
In 2001 Tjan HL, Miller JD presented a combination treatment approach to an esthetic defect
resulted from diastema and peg shaped lateral incisors. Minor tooth movement and full coverage
PFM crowns on lateral incisors were completed and then the orthodontic correction of local tooth
Smile designmalposition through a removal appliance was done. He concluded that these simple procedures
may be valid in optimizing the mechanical and esthetic properties of prosthodontic restoration.
Mohlt W F, Hovijitra S in1999 stated that closing maxillary and mandibular diastemas is
facilitated by a multidisciplinary approach involving orthodontics and prosthodontics. This case
study demonstrated the management in the discrepancy in maxillary and mandibular anterior
teeth widths. The problem is resolved by limited orthodontic treatment followed by porcelain
laminate veneers. Anterior spacing is one of the major reasons adults seek esthetic treatment.
Multidisciplinary treatment ( periodontics, orthodontics and prosthodontics) is often indicated for
an optimal results.
Haywood V.B. in 1996 stated that bleaching of teeth is the reasonable choice if color of the
teeth is the main concern. However the patient should understand that this procedure is only
considered a temporary measure. Furthermore , whiter teeth are merely an interim measure if
smoking or excessive drinking of liquids that stained are continued.
Antonio Bello and Ronald H. in 1997 stated that if the patient wishes to improve their smile
because of dark spaces between the teeth, esthetic bonding with composite is the most
conservative approach for several reasons----
a) Sound tooth structure will not be removed.
b) One appointment is common.
c) Anaesthetics are infrequent
Carlos Eduardo Francischone et al stated that with the integration of many specialities, it is
possible to achieve the desired esthetics foe anterior prostheses and to develop a harmonious
transition to the surrounding periodontium.
Smile design Roy Sabri in 1999 concluded that missing maxillary lateral incisors with any coexisting
malocclusion must be managed within an overall treament plan.
Factors related to patient , size, shape and position and color of the teeth ; the effect of occlusion;
the overall facial and dental esthetics should be considered when deciding on whether to create
an orthodontic space opening or space closure.
In 1985 Shapiro described a technique on periodic curettage to stimulate the overgrowth of
interdental papilla destroyed by acute necrotising ulcerative gingivitis.
Han and Takie H.H. in 1996 described a technique consisting of a pedical graft using a
semilunar incision and the coronal displacement of entire gingival papillary unit.
Raetzke PB in 1985 described the use of a connective tissue graft placed under a flap for the
purpose of root coverage.
CONCLUSION
Dentistry is an ever changing science.As new research and clinical experience broaden our
knowledge,changes in treatment are required.This paradigm shift in the field of dentistry comes
along just in time to meet the final needs and wants of patient who perceives an attractive smile
no longer as a luxury but rather a necessary part of their life style.Aesthetic dentistry enables the
dentist to change the appearance,size,color,shape,spacing,positioning of the teeth. The allure of
conservative preparations,the potential for excellent esthetic results and gingival
Smile designHealth has made this branch of dentistry very popular over the world.No wonder it has enjoyed
such a wide spread utilization and at the same time proven itself with such predictable and
excellent results.
Dr. Charles Pincus is rightly recognized as the Father of esthetic dentistry made a prophetic
statement in the year 1937 which is quoted as “A captivating smile showing an even row of
gleaming white natural teeth is a major factor in achieving the dominant characteristic known as
personality.This entails a lack of inferiority complex which causes a hand to be raised to cover
the mouth.
It is this lack of confidence in the dental equipment, which often spells the difference between
success and failure in the life of many people.
The above statement was true in the year 1937 is a reality today and will be so in the years to
come.
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1. Solomon EGR: Esthetic consideration of smile; J of IPS 1999: 10(3&4);
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Smile design7. Kamal Shigli, Swaraj Bharati: Role of technology in designing a confident smile. J.
IPS Dec. 2001, vol.1, no.4.6)
8. Friedman, MJ and Hodcman, M.N.: P-ASA Block injection: Anew palatal technique
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