Download - Review of Literature
Review of literature:
Orban F et al. (Dimensions and Relations of the Dentogingival Junction in
Humans. J. Periodontol (1961 32:261))
In their study measured dimensions of tissues involved in Biological Width
considerations. Used histologic sections to measure average dimensions of
biologic width. These are not clinically accurate due to distortion with
histologic processing. This study said width of junctional epithelium plus
connective tissue width was Biologic width; i.e.approximately 2 mm. If a
subgingival crown margin is placed in the middle of the gingival sulcus, the
crest of bone should be a minimum of 2 mm apically positioned. mean depth
of the histologic sulcus is 0.69 mm,mean junctional epithelium measures 0.97
mm (0.71 to 1.35 mm),mean supraalveolar connective tissue attachment is
1.07 mm (1.06 to 1.08 mm).The total of the attachment is therefore 2.04
millimeters (1.77 to 2.43 mm) and is called the biologic width.
James s Marcum et al, J Prosthet Dent. 1967 May;17:479-487
studied the effect of crown marginal depth upon gingival tissue.,
Sixty six crowns were placed and finished above, below, and even with the
gingival crest in 6 dogs. the crowns were left in place until the dogs were put to
death at time intervals of one ,two, and three months. two dogs were sacrificed
at each interval, block specimens of the teeth and gingiva were taken at this
time. Control specimens of unoperated teeth were also taken. The block
specimens were decalcified,sectioned,stained,histologically examined,and
graded for severity of inflammatory response.six hundred histological slides of
the tissue sections were graded as having evidence of none,slight,moderate or
severe gingival inflammation.
The investigation showed that crowns with margins located at or even with the
gingival crest caused the least inflammatory response; that crowns with margins
located above and below the crest cause the most severe inflammatory response.
The length of time a restoration was in place had little if any effect upon the
severity or degree of inflammation.
Choosing the proper crown marginal depth depends upon many factors.however
it appears from the results of this investigation that crowns with the gingival
crest would be least likely to cause gingival inflammation.
Yuodelis et al,
J Prosthet Dent. 1973 jan;29:61-6
Studied about the esthetics and hygiene in crowns given after periodontal
therapy that involves osseous resection procedures or following gingival
recession,we are often confronted with longer than normal clinical
crowns.these lengthened clinical crowns are much more difficult to keep
plaque free due to the exposed furcations and root flutings. If plaque is
allowed to accumulate for long periods of time ,demineralization of the
cemental surfaces will rapidly cause increased sensitivity and root caries. If
root portions must be covered by complete artificial crowns ,the gold castings
should not frustrate the oral hygiene efforts of patients.
The final restoration should not follow the original anatomic crown and should
recreate the original contours of the root portion.the modification of the
anatomic coronal form entails reduction of unnecessary bulges in order to
create additional accessibility to gingival third of the fluted and furcation
regions.this will eliminate the triangular region that is created by the roots and
cervical bulge and which is the area most difficult to maintain in a plaque-free
condition by normal brushing.for this reason we endeavour to flatten the facial
and lingual contours of restorations and have observed excellent gingival
response.most probably the cervical region is made more accessible for
routine home care.
D. Tarnow et al( Journal of Clinical Periodontology Volume 13, Issue 6, pages
563–569, July 1986)
Studied Human gingival attachment responses to subgingival crown placement
and marginal gingival remodelling.
13 teeth in block were extracted from 2 patients. Their facial periodontal
condition was essentially within normal clinical limits. Temporary crowns
covering the bevel were placed below the base of the crevice 1 to 8 weeks prior
to extraction. At time of extraction, all blocks were decalcified, the temporary
crown dissolved, and the blocks prepared for histologic examinations using
bucco-lingual cut, step serial sections.
Histologic data revealed reformation of a new supracrestal attachment unit
within 1 week following crown placement. The reformation of the gingival unit
consisted of marginal recession with apical and lateral migration of the
junctional epithelium to the level of remaining cementum inserted fibers. With
gingival recession and migration of junctional epithelium, resorption of crestal
portions of the facial plate occurred. However, periodontal fibers anchored into
cementum opposite the resorbed bone were not lysed. Rather, the attached
fibrillar ends appeared to interdigitate with fibers from the corium of the facial
gingiva at this site, thereby forming a more apically located crestal attachment.
This response may be one mechanism of reformation of the gingival attachment
unit taking place following mechanical and/or surgical injury to this site and is
completed often, within 2 weeks after injury.
Geoffrion J.et al 1989.
[Transformation of a lateral incisor to a central incisor with a ceramometal
crown].
They gave guidelines to change a maxillary lateral incisor into a central incisor
by using a ceramo-metallic crown. It is required to schedule a rational plan of
treatment. All the different pre-prosthetic (orthodontic, periodontic, and
endodontic) and prosthetic steps are described and justified. In order to
achieve a compromise between esthetic and a stable periodontium the mesial
profile of emergence of the ceramic should be conceived to prevent any
overcontour.
Croll BM.et al
(J Prosthet Dent. 1990 Apr;63(4):374-9.)
In their study showed that Selection of the straight emergence profile in
designing artificial crowns for teeth has been shown to improve the
effectiveness of oral hygiene near the gingival sulcus. The axial profile of teeth
can be viewed as a series of straight lines with curved transitions.
Reproduction of these geometric patterns facilitates fabrication of restorations
that appear natural.
Ferencz JL.
(J Prosthet Dent. 1991 May;65(5):650-7.)
Reviewed about Maintaining and enhancing gingival architecture in fixed
prosthodontics.
The long-term success of fixed prosthodontic restorations is greatly dependent
upon the health and stability of the surrounding periodontal structures. This
article deals with the interrelationship between fixed prosthodontic
procedures and the stability and health of the periodontium. The commonly
encountered problem of alterations in gingival architecture is examined in
relation to tooth preparation as well as soft tissue preparation. In addition, the
ability of the provisional restoration to guide soft tissue form is discussed as
well as the role of the final restoration in providing long-term tissue
maintenance. Key factors such as margin placement, tissue damage during
tooth preparation, the role of the provisional restoration, tissue injury during
impression procedures, crown contour, pontic design, and embrasure design
are all important factors to be considered to achieve a good emergence profile.
Donald F. Reikie et al (J Prosthet Dent 1993;70:433-7)
Did a review of esthetic and functional considerations for the partially
edentulous implant candidate. Stated that with the availability of adjunctive
grafting procedures, it is time for the implant team to change the traditional
treatment planning approach that allows patient anatomy to dictate implant
position and prosthesis design. Dimensions of the edentulous space and
evaluation of occlusal relationships are discussed by the author. Soft tissue
ridge contour and creation of favorable cervical harmony are also reviewed.
Functional demands unique to the partially edentulous patient are outlined in
addition to the challenges of creating a prosthesis with natural cervical form
and emergence profile.
David Neale et al (J Prosthet Dent 1994;71:364-8)
Describes a technique to help predict, develop, and evaluate implant
prostheses and their soft tissue contours at the provisional restoration stage.
This technique records the planned and subsequently proven contours, which
are then used to guide fabrication of the final prosthesis and produce a
predictable esthetic result.
Shavell et al
(Pract Periodontics Aesthet Dent. 1994 Jan-Feb;6(1):33-44; )
Suggested that the delicate dento-gingival attachment apparatus must be
treated with utmost respect during all preparational maneuvers in the
crevicular region. There is little room for error within these minute dimensions.
To avoid irreparable harm during chemo-mechanical manipulation of the
attachment apparatus, the dentist must always think on a histologic level in
order to respect the cellular integrity of the periodontium.
C. YOUNGSON et al. 1996
They studied about the preparation form and emergence profiles of maxillary
metalloceramic crowns .
The aim of their study was to compare the emergence profiles of crowns with
their contralateral tooth, in vitro, and determine if there is any association
between the design of tooth preparations and the resultant emergence profile.
In this study 50 models used for single crown construction were examined.
Measurements of the faciolingual width of the crowns and contralateral teeth
were taken using digital calipers. Internal line angles and the margin width of
dies and the emergence profile of the corresponding crowns were measured
from longitudinally sectioned polyvinylsiloxane indices of preparations and
associated crowns mounted on a flat-bed scanner using image analysis
software.
In this in vitro study, they concluded that the emergence profiles of crowns
were higher than the contralateral teeth. Maxillary metalloceramic crown
preparations had shoulder widths that did not conform to recommendations in
standard texts but line angles were within a satisfactory range. The margin
width exerts a weak effect upon the emergence profile of the crown.
Davidoff SR et al
(J Prosthet Dent. 1996 Sep;76(3):334-8)
Described a procedure for late stage soft tissue modification for achieving
anatomically correct implant-supported restorations. Author presents a simple
method of modifying soft tissues coronal to the implant head that will allow
the development of a restoration with correct emergence profile and anatomic
contour.
Reeves WG.et al 1996
Studied the restorative margin placement and periodontal health.
Subgingival restorative margins are associated with the development of
plaque-related inflammatory periodontal disease, primarily because of a shift
in the subgingival microflora from a profile associated with health to one
associated with disease. The degree and extent of the marginal inflammation is
influenced by four factors: failure to maintain proper emergence profile,
inability to adequately finish and/or close subgingival margins, placement of
subgingival margins in an area with minimum to no attached gingiva, and
violation of the biologic width. Supragingival margin placement is the location
of choice for all restorative margins to avoid iatrogenic periodontal disease.
However, consideration of these four factors will help reduce the adverse
impact of restorative margins that must be carried subgingivally.
Souheil Hussaini et al (J Prosthet Dent 1997;77:630-2)
Describes a procedure that enables the clinician to fabricate a full-arch
maxillary provisional restoration for a fully edentulous patient, which can be
delivered at second-stage surgery at the time of uncovering the implants. It
satisfies the patient's esthetics, phonetics, and functional demands and helps
create a good emergence profile for the healing gingival tissue.
Kleber BM et al 1997
Studied about the Influence of marginal and submarginal restoration margins
on periodontal tissues.
They concluded that Subgingival and irregular restoration margins have an
unfavourable influence on the marginal periodontal tissues. The margins close
to the gingiva of 206 restorations (age of restorations mean = 49.4 months)
showed incorrectnesses in most cases with marginal inflammation as a result.
That's why the demand of high precision, supragingival positioning of margin
restoration and removal of all potential plaque-retentive or mechanic irritated
surface is raised.
Salinas TJ et al
(Pract Periodontics Aesthet Dent. 1998 Jan-Feb;10(1):35-42)
Establishing soft tissue integration with natural tooth-shaped abutments.
Stated that the disparity in dimensions between implant fixtures and the
exposed extraction sockets has resulted in the development of anatomically
shaped abutments. Systems have been recently introduced that facilitate the
fabrication of abutments to the configuration of natural teeth in the anterior
maxilla. These systems permit development of an aesthetic emergence profile
and contours for easy access in maintenance of oral hygiene of maxillary
anterior single-tooth implant-supported restorations. The rationale for the
development, indications, advantages, and clinical utilization of a recently
introduced abutment system is discussed by the author.
Papazian S et al (J Prosthet Dent. 1998 Feb;79(2):232-4)
Described a laboratory procedure to facilitate development of an emergence
profile with a custom implant abutment.when an implant abutment must be
customized,access to coronal portion of the implant analog requires ditching of
the artificial stone on the master cast.In this procedure the author uses an
orthodontic elastic band with a square cross section to produce space around
the coronal aspect of the analog and eliminate the need for ditching.
Tung FF
( J Prosthet Dent. 2000 Jun;83(6):681-5.)
Describes a procedure for simultaneous registration of gingival emergence
profile and maximal intercuspal position for metal ceramic restorations. The
materials used in this procedure are inexpensive, readily available, and easy to
use. The clinician can inspect the framework, cast, and tissue profile before
sending them to the laboratory. When this method is properly used, it allows
better communication with the dental technician, saves chair time, and
reduces the number of laboratory procedures as currently practiced.
Schätzle M et al
(J Clin Periodontol. 2001 Jan;28(1):57-64.)
Studied the influence of margins of restorations of the periodontal tissues
over 26 years.The aim of this study was to examine the long-term relationship
between dental restorations and periodontal health.The data was derived
from a 26-year longitudinal study of a group of Scandinavian middle-class
males characterized by good to moderate oral hygiene and regular dental
check-ups. At each of 7 examinations between 1969 and 1995, the mesial and
buccal surfaces were scored for dental, restorative and periodontal
parameters. The mesial sites of premolars and molars of 160 participants were
observed during 26 years (1969-1995). A control group with 615 sound
surfaces or filling margins located more than 1 mm from the gingival margin in
all 7 surveys was compared with a test cohort with 98 surfaces which were
sound or had filling margins located more than 1 mm from the gingival margin
at baseline (1969) and had a subgingival filling margin 2 years after (1971).
The study confirmed the long held concept that restorations placed below the
gingival margin are detrimental to gingival and periodontal health. In addition,
this study suggests that the increased loss of attachment found in teeth with
subgingival restorations started slowly and could be detected clinically 1 to 3
years after the fabrication and placement of the restorations. A subsequent
"burn-out" effect was suggested.
Davarpanah M,
(Pract Proced Aesthet Dent. 2001 Nov-Dec;13(9):761-7; quiz 768, 721-2.)
Described about a three-stage approach to aesthetic implant restoration:
emergence profile concept. The three-stage approach of the emergence profile
concept guides the selection of implant, healing abutment, and provisional
prosthesis. Adaptation of the implant, provisional prosthesis, and crown
restoration stages and their harmonious integration with the soft tissues
enable the development of an optimal aesthetic result.The author
demonstrates the incorporation of the emergence profile concept for aesthetic
implant placement.
Song-bor kuo et al (J Prosthet Dent 2002;88:646-8)
Describes a method for fabricating an optimal emergence profile for the
definitive restoration of an ITI solid abutment when the implant is installed
subgingivally. Here the definite restoration for ITI solid abutment is fabricated
by waxing on the plastic coping ,casting the metal coping and adding
porcelain on the metal coping. The soft tissue model is used to adjust and
finalize the emergence profile during these different laboratory procedures. As
the subgingival configuration of the modified impression cap is performed in
the lab ,this technique may reduce chair time. The result of the peri implant
mucosal health serves to verify that the emergence profile is acceptable. This
technique cannot be applied to the narrow neck implant abutment and angle
abutment because they do not use a similar impression cap.
Michael Tischler et al. 2004
Dental Implants in the Esthetic Zone Considerations for Form and
Function .The concept of emergence profile is important when dealing with
implant esthetics. The emergence profile can be obtained three different ways.
One way is for the healing abutment to form the surrounding soft tissue. The
second way to sculpt the tissue around an implant is to have the implant
abutment create ideal form. This can be done with a custom abutment at
either first or second stage. If the abutment is used to create the emergence
profile at first stage, then the criteria for immediate loading must be
considered. The third way to create the emergence profile is to allow a
provisional restoration to sculpt it. This can be done either with an ovate
pontic or with the contours of a cemented restoration at either first- or
second-stage surgery.
Daniel C.T.Macintosh et al. (J Prosthet dent 2004 ;91:289-92)
The author describes a method for creating an improved emergence profile
with single-tooth, implant-supported restorations. An easily trimmed silicone
gingival substitute is used to allow polymerization of acrylic resin provisional
restorations to achieve control of the emergence profile. Gingival trauma is
minimized by eliminating intraoral use of monomer and minimizing surgical
procedures. Provisional restorations can be assessed to ensure the contour is
acceptable and the trimmed gingival substitute can be used to fabricate a
similar profile in the definitive prosthesis. The provisional restorations may be
used instead of standard prefabricated healing abutments to guide the healing
contours of the peri-implant gingival tissue.
Mario R. Ganddini et al. (J Prosthet Dent 2005;94:296-8)
Suggested that the fabrication of provisional restorations is an important stage
in implant treatment. In the esthetic zone, the potential for error without the
use of provisional restorations in the selection of the abutments, framework
design, appropriate vertical dimension of occlusion, occlusal profile, and the
esthetic interpretation may be significant. Provisional restorations are
indicated in esthetic zones, for the contouring of the gingiva, to achieve an
acceptable emergence profile, to have custom-guided tissue healing, and to
induce appropriate soft-tissue topography. They described the fabrication of a
provisional restoration for a single-unit implant-supported crown.
Sundh B et al.2005
Did an in vivo study of the impact of different emergence profiles of procera
titanium crowns on quantity and quality of plaque.The purpose of this study
was to evaluate the effect of crowns with different emergence profiles on
marginal plaque formation.
Seven crown preparations were performed on premolar teeth in six patients.
Four titanium crowns for each tooth--with different marginal emergence
angles--were manufactured according to the Procera technique. The three
experimental crowns and the final permanent tooth were cemented with
phosphate permanent cement. Plaque samples were collected from the
marginal area after 1 week with normal oral hygiene, and again after refraining
from oral hygiene for 2 days. The contralateral tooth served as a control. The
quantity and quality of plaque were registered. The restoration was removed,
the next crown version cemented, and the protocol repeated.
All experimental crowns, irrespective of emergence profile, showed a
significantly lower (P = .01) plaque quantity than controls. No intraindividual
differences were found regarding the accumulation of mutans streptococci at
the different experimental emergence profiles. No differences in quality
between experimental and control sides were found.
Within the limitations of this study, it was found that titanium crowns with
emergence profiles of up to 40 degrees formed less plaque than healthy
controls. There was no higher accumulation of mutans streptococci in relation
to increasing emergence profiles.
Yotnuengnit B et al
(Quintessence Int. 2008 )
Did a study to find the geometric values of emergence angles in human natural
anterior teeth and to study their influence on periodontal status.
Fifty anterior teeth with full-crown restorations and homologous contralateral
sound teeth were examined for clinical parameters: Plaque Index, Gingival
Index, probing depth, and clinical attachment loss. Impressions and stone casts
were made and then separated along the midline of the teeth. All cut-surface
specimens were photocopied, scanned, and transferred into graphic form with
a special program. The emergence angles of both restored and natural teeth
were processed and recorded. Paired t test and multivariate linear regression
analysis were used for statistical analysis.
Mean supragingival emergence angles for facial and lingual surfaces of natural
anterior teeth were 11.13 +/- 7.92 and 15.58 +/- 9.16 degrees, respectively.
The corresponding values for subgingival emergence angles were 9.93 +/- 5.68
and 14.35 +/- 8.44 degrees. The periodontal parameters were higher in
restored teeth than in natural teeth. When Plaque Index and gender were
controlled, a correlation was shown between the lingual subgingival
emergence angle of the restored teeth and probing depth. A correlation was
also found between the lingual supra- and subgingival emergence angles, as
well as between both angles of the restored teeth and the attachment loss.
They concluded that the mean values of emergence angles obtained may aid
clinicians and dental technicians in more easily designing the definitive
emergence profile of restorations. The emergence profile of the restored teeth
may affect periodontal status on the lingual aspect.
Nihon Hotetsu et al. 2006
Presented a case of interdental papilla reconstruction with prosthodontic
treatment of maxillary central incisor.
A 20-year-old female whose chief complaint was esthetic disturbance of a
crown placed on the maxillary left central incisor.
The interdental papilla was reconstructed only by the prosthodontic treatment
of maxillary left central incisor. This case suggests that the proximal and
subgingival contours of provisional crown is very important to the
reconstruction of interdental papilla, and also suggests that the transmission of
the information regarding the configuration of a provisional crown to the lab
side is very important.
This case showed that the emergence profile of a single crown, especially of its
proximal aspect, is important to reconstruct the interdental papilla.
Saad A. Al Harbi et al (J Prosthet Dent 2007 ;98:329-332)
Describes a proceduce for a patient with a missing or failing maxillary anterior
tooth desiring for immediate tooth replacement.Here the fabrication of a
provisional restoration can be challenging. Due to individual anatomical
variations in tooth shape, size, and supporting soft and hard tissue structures,
there are no premanufactured components with an anatomical emergence
profile that universally suits all individual situations. The author describes the
fabrication of a screw-retained immediate provisional restoration that fulfills
anatomic, biologic, and esthetic requirements.
Nicolas Elian et al (J Prosthet Dent 19:306-315,2007)
Described a method of accurate transfer of peri-implant soft tissue emergence
profile from the provisional crown to the final prosthesis using an emergence
profile cast.
The use of impression copings to make the final impression results in a master
cast in which the soft tissue configuration around the implant platform is
circular. Therefore, any soft tissue sculpting developed clinically by the
provisional restoration is squandered.
The purpose of this report was to present a method for the precise transfer of
the peri-implant soft-tissue developed by a customized provisional restoration
to an emergence profile cast.The emergence profile cast is obtained from an
impression of the implant-supported provisional restoration and poured with a
soft tissue model material. It is used for the fabrication of the emergence
profile of the implant abutment and the cervical section of the crown.The
technique described was simple, accurate, predictable, and does not require
additional chair time for the customization of the impression coping or the
fabrication of a new provisional restoration.
This article describes a technique that results in an implant restoration that
mimics accurately in its emergence profile that of the carefully crafted and
customized provisional restoration. The reproduction of the soft tissue contour
from the provisional to the final restoration results in an improved esthetic
outcome of the final restoration.
Amina Mohamed Hamdy et al. Jan 2008
18 patients were selected from the out patient dental clinic of Faculty of
Dentistry , Ain – Shams University according to certain criteria . patients were
randomly divided into 3 groups ( n = 6) . In the first group patients received
fibre reinforced composite full coverage crown (FRC) , in the second groups ,
they received full coverage metal ceramic crowns , with metal collar margin
(MCR) , while in the third group , they received full coverage all – ceramic
crown (In ceram ) . These groups were further subdivided into two equal
subgroups (n = 3 ) , in subgroup A , the finish line was placed 0.5-1 mm
subgingivally , while in subgroup B , it was placed 0.5 – 1 mm supragingivally.
After proper assessment of the crowns , they were cemented using adhesive
resin cement (panavia F) . Gingival health was investigated according to plaque
index (PI) , sulcus bleeding index (BI) and pocket depth (PD) . The
measurements were taken immediately after crown cementation (baseline, o )
then after 3 month (3), at the mesial , distal , buccal and lingual surfaces for
each crown. Also, control teeth ( contra lateral teeth with no restorations) ,
were assessed similarly . statistical analysis was carried using Graphpad Prism
version 4.03. Fisher’s exact test and Chi square test were performed to
compare between categorical data . Results . Regarding plaque index group I
( FRC) ,subgroup A (Subgingival) showed higher significant difference (P =
0.015) after 3 months than at baseline , while no significant differences were
observed in any of the other groups or subgroups regarding sulcus bleeding
index (BI) or pocket depth (PD) . Also , all control teeth showed no significant
changes rather than tested crowned teeth or after 3 months from baseline
regarding the three different parameters . Conclusions . Plaque index has
increased significantly around subgingival margins of fibre reinforced
composite full coverage corwns while no changes in the sulcus bleeding index
or pocket depth was observed after 3 months of crown placement regardless
the material of construction or margin location .
Athanasios Ntounis et al.(2008)
This article describes an indirect impression technique that accurately captures
the soft tissue contours around an implant-supported provisional restoration.
Customized impression copings are used to transfer the soft tissue architecture
created by the interim prosthesis. The definitive restoration is shaped like the
provisional restoration, maintaining the emergence profile and optimizing
esthetics.
Alexander shor et al. (J esthet restor Dent 20:82-97,2008)
Suggested that fixed provisional restoration can also seve as an esthetic and
functional blue print in the fabrication of the definitive restoration.this article
presents a production technique and treatment workflow of a laboratory
fabricated ,screw retained fixed provisional restoration.provisional restoration
is fabricated using layering technique and internal stain charecterization.the
soft tissue profile of the working cast is modified according to the coronal
contour of diagnostic wax up.the developed emergence profile of provisional
restoration is transferred to master cast via customized impression coping.
Den Hartog L et al (J Prosthet Dent. 2009 Oct;102(4):211-5)
describes a treatment in which an anterior maxillary implant was immediately
restored with a provisional restoration. During the provisional phase, an
optimal emergence profile was created by adjusting the provisional
restoration. An impression was made with an individually fabricated
impression post for an accurate reproduction of the established emergence
profile and, finally, a screw-retained all-ceramic crown was placed. By
implementing this protocol, an optimal definitive result could be achieved,
together with immediate patient satisfaction. However, cooperation among
several disciplines and careful patient selection were required.
Panagiota eirini et al (J Prosthet Dent 2009;102:345-347)
Suggested that Obtaining an accurate representation of the soft tissue
contours developed around an implant in the esthetic zone is crucial to the
success of a restoration. The technique presented emphasizes “guiding” of the
soft tissue by modifying a provisional restoration to obtain an emergence
profile that appears natural and blends with the gingival contour of the
adjacent teeth. The technique provides an accurate impression of the soft
tissue through the intraoral use of autopolymerized acrylic resin supported by
the impression coping and vinyl polylsiloxane impression material. The
eventual restoration uses an esthetic zirconia custom abutment and an
implant-supported single crown to fulfill the esthetic and functional
expectations of the patient and the provider.
Azer SS. Et al
(J Prosthodont. 2010 Aug;19(6):497-501)
Described a simplified technique for creating a customized gingival emergence
profile for implant-supported crowns.This is also an economical technique to
direct gingival tissue healing, as well as create a removable gingival replica of
the customized gingival emergence profile. The created profile can then be
used in the dental laboratory to achieve a superior and predictable esthetic
outcome for implant-supported fixed restorations.
Jofre et al 2010
In their clinical report concluded that, Immediate provisionalization is
considered to be an advantageous procedure for aesthetic results in
immediate implant placement. Despite reports of
techniques and procedures that use the patient’s teeth,
these cannot always be recovered. The method
described offers a chairside alternative for fabricating
an immediate provisional for a single implant, replicating
the pre-existing anatomical crown with acrylic. Acrylic
is easier to handle for this procedure, and allows the
periodontal structures to be preserved.
The applications of this technique are extensive,
and can be used on anterior and posterior teeth as
well as fixed partial prosthetics and bridges.
Takahiko Sugiyama et al 2010
Used a system called friction system to achieve a esthetic emergence profile.
The Friction Retention System has many considerable advantages
and plays an important role in achieving perfect
treatment results. The indication is restricted to single tooth
replacement and that the limit is a three unit bridge.
In addition, implant placement conditions and securing
suffi cient tissue volume surrounding the implant are fundamental
to its success. ■
Beitlitum L et al 2011
Did a review on teeth replacement in the esthetic zone . Dental implants are
usually the preferred treatment alternative for tooth replacement.in this
review they discussed several clinical issues concerning implant placement in
the esthetic area. It is still unclear whether raising a flap at the time of implant
placement enhances alveolar crest remodeling. However, a flapless surgical
procedure could avoid changes in the free gingival margin and maintain the
the attached gingiva width. A submarginal approach not involving the free
gingival margin can be applied to treat bone defects with the GBR technique.
Implants should be placed as palatal as possible while maintaining optimal
restoration emergence profile and the horizontal bone defect filled with a non
resorbable material such as bovine bone mineral. Thick periodontal biotype
and coronally positioned free gingival margin usually lead to better results.
Immediate implant placement in presence of a periapical lesion may be
performed, however, sites should be thoroughly debrided prior to implant
placement.
Degidi M et al
(J Periodontol. 2011 May;82(5):708-15. Epub 2010 Dec 7)
Did a histologic and histomorphometric evaluation of nine equicrestal and
subcrestal dental implants retrieved humans.they did this study considering
that the stability of peri-implant crestal bone plays a relevant role relative to
the presence or absence of interdental papilla. Several factors can contribute
to the crestal bone resorption observed around two-piece implants, such as
the presence of a microgap at the level of the implant-abutment junction, the
type of connection between implant and prosthetic components, the implant
positioning relative to the alveolar crest, and the interimplant distance.
Subcrestal positioning of dental implants has been proposed to decrease the
risk of exposure of the metal of the top of the implant or of the abutment
margin, and to get enough space in a vertical dimension to create a
harmoniously esthetic emergence profile.
A retrospective histologic study was performed to evaluate dental implants
retrieved from human jaws that had been inserted in an equicrestal or
subcrestal position. A total of nine implants were evaluated: five of these had
been inserted in an equicrestal position, whereas the other four had been
positioned subcrestally (1 to 3 mm).
In all subcrestally placed implants, preexisting and newly formed bone was
found over the implant shoulder. In the equicrestal implants, crestal bone
resorption (0.5 to 1.5 mm) was present around all implants.
They concluded that the subcrestal position of the implants resulted in bone
located above the implant shoulder and thus a good emergence profile can be
achieved.
Avinash S. Bidra et al (Journal of Oral and Maxillofacial Surgery june 2011)
Omega-Shaped (Ω) Incision Design to Enhance Gingival Esthetics for Adjacent
Implant Placement in the Anterior Region.
Describes a technique to achieve a papilla-like tissue using an omega-shaped
(Ω) incision design when implants are placed adjacent to each other in partially
edentulous ridges. This incision design is intended to spare an area of soft
tissue of approximately 4 mm × 4 mm between the anticipated positions of the
adjacent implants. The area of soft tissue that is free from surgical insult later
helps in the creation of a papilla-like tissue through interim restorations.