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Why to Restore

Teeth?The objectives of restoring teeth are:

To remove diseased tissues as necessary To restore the integrity of the tooth

surface

To restore function of the teeth To restore aesthetics

To reduce or eliminate symptoms

(pain)



Fracture lines



CUSTOM PROVISIONALCUSTOM PROVISIONAL

RESTORATIVE MATERIALSRESTORATIVE MATERIALS

CUSTOM PROVISIONALCUSTOM PROVISIONAL

RESTORATIVE MATERIALSRESTORATIVE MATERIALS

LCDR R. L. Gunning, DC, USN



A dental prosthesis worn for various periods

of time which maintains:

esthetics, provides masticating surfaces

and protects the har d and soft tissues prior to the

delivery of the definitive prosthesis. ± LCDR R. L. Gunning,DC, USN



Provide pr edictable outcome

R elates functional and esthetic r equir ements

Satisfy:

1- biologic,

2- mechanical,

3-and esthetic r equir ements

Purpose



Pulp protection

Periodontal health

Positional stability

Biologic Requirements



Durable

Easily r emoved

Diagnostic aid

Mechanical R equir ements



-Textur e, color, and translucency

-Color stability

-Guide to optimum esthetics

Esthetic

R equir ements



-Convenient handling

-Biocompatibility

-Dimensional stability

-Easily contour ed and polished

-Adequate str ength and abrasive r esistance-Esthetic

Ideal PropertiesIdeal Properties



The transitional r estoration serves as:

- a medium of communication of many of the patient¶s f ears, anxieties, and dee p concerns about

the loss of facial appearance, ³normal ex pr ession´,

r etention clarity of speech,

-and the ability to continue participation in socialfunctions.



Diagnostic casts and wax-upMatrix fabrication

Tooth pr e paration and provisional

r estoration construction

Interim stage tr eatment evaluation



Defective Tooth Structure

Conditions That Require Repair

Dental caries

Tooth wear

Trauma

Developmental defects



DENTAL CARIES -Is a bacterial disease of the calcified tooth

structure characterized by intermittent periodsof demineralization and remineralization .

-When the net effect is demineralization loss ofthe mineral component of the tissue isaccompanied by disintegration of the organicmaterial and cavitations results



Dental CariesDental Caries

Definition &

Etiology



Dental cariesDental caries

Etiology of Dental Caries:

MAJOR FACTORS

1. Role of bacteria

Normal flora of the oral cavity contains abundance of bacteria which derive ther e energy by the chemical process of f ermentation

Mainly the bacteria ar e Str e ptococcus Mutans,andstr e ptococcus sobrinus collectively known mutansstr e ptococci(MS)



Dental caries

2. Role of plaque:

Plaque is an adhesive layer which de positson the surface of the tooth and has colonies

of bacteria

Plaque tends to stick to the surface of the teeth and in this way the bacteria can have ther e cariogenic eff ect on the tooth

Incr ease bulk of the plaque



Dental cariesDental caries

Plaque on the surface of

the tooth (enamel)



Dental cariesDental caries3. Role of saliva:

It plays role in incr easing the cariogenic

eff ect on the teeth and as well it has the

buff ering action.

Saliva has a cleansing eff ect also



Dental cariesDental caries4. Role of carbohydrates:

Fermentable carbohydrates ar e on of the most

important cause of causing dental caries.

Incr ease in the intak e of r efined carbohydrates ar e dir ectly proportional in causing the dental caries

Diff er ent studies and indicies have been done in or der to know the role of carbohydrates in causing the dental caries.



Dental cariesDental caries Dietary sugars ar e mainly sucrose which is

cheap and easily produced from sugar cane

and has very high calories sucrose is pr esentin wheat and potatoes.

Sucrose substitutes ar e palatinose,Tr ehalulose and sugar alcohols



Dental cariesDental cariesMINOR FACTORS:

Enamel composition

Morphology of the tooth

P

osition of the tooth Diet

Immunity



MICROB

IOLOGY

MICROB

IOLOGY



Dental cariesDental cariesMICROBIOLOGY

1. Bacteria involved :

Str e ptococci e.g mutans, sobrinus

Lactobacilli e.g acidophilus

2. Possibly associated bacteria:

Ste ptococci e.g mitis

Actinomyces e.g viscosus



BacteriaBacteria



Essential factors for caries

formation

Tooth

Suitable diet

carbohydrates

TIMEMicroorganisms



Amore recent model

Amore recent model



Etiology of Den. Caries

These factorsThese factors work work together in the followingtogether in the followingmanner :manner :

--Some plaque bacteria ar e capable of f ermenting aSome plaque bacteria ar e capable of f ermenting a

suitable dietary carbohydrate substrate {sugars,suitable dietary carbohydrate substrate {sugars,sucrose,glucose }sucrose,glucose } to produce acidsto produce acids , causing the plaque , causing the plaque

pH to fall below pH to fall below 55 or or 44..55 withinwithin 11--33 minutes.minutes.

-- Unfortunately the plaque r emain acidic for some Unfortunately the plaque r emain acidic for some

time .time .

--TakingTaking 3030 ---- 6060 minutes to r eturn to its normalminutes to r eturn to its normal

pH in the r egion of pH in the r egion of 77..



CLASSIFICATION OF

DE NTAL CARIES



Classification of dental caries1 - Primary lesion

- Secondary lesion

2 - Active - Arrested

3- Location (G.V.Black)class I pits and fissure caries

class II approximal caries posterior.T. class III approximal caries anterior .T. class VI approximal caries of anterior teeth involving the incisal angle class V cervical surfaces.

Class VI (Simon¶s modification): r estoration involving cuspal tips and

incisal edges of teeth.

4- (Location ) -root caries

-coronal caries



1.Based On Anatomical Site

2.Based On Progr ession

3.Based

On Virginity Of Lesion

4.Based On Extent Of Caries

5.Based On Tissue Involvement

6.Based On Pathway Of Caries Spr ead

7. Based On Number Of Tooth Surface Involved

8. Based On Chronology

9 .Based On Whether Caries Is Completely R emoved Or Not

During Tr eatment10.Based On Tooth Surface To Be R estor ed

11.Black¶s Classification

12.Who System



11.BASED ON AN ATOMIC AL .BASED ON AN ATOMIC AL

SITESITE

OCCLUSAL

(PIT AND

FISSUR E)

ROOT

CARIES

SMOOTH

SURFACE

CARIES

(PROXIMAL

AND CERVICAL

CARIES)

LINEAR

ENAMEL

CARIES



22..BASED ONBASED ON

PROGRESSIONPROGRESSION

ACUTE CARIES

CHRONIC CARIES

ARR ESTED CARIES



Exclusively seen in caries of occlusal surface with large opencavity in which ther e is lack of food r etention

Also on the proximal surfaces of tooth in cases in which theadjacent approximating tooth has

been extracted



33.BASED ON VIRGINITY OF.BASED ON VIRGINITY OF

LESIONLESION

INITIAL/PRIMARY R ECURR E NT/SECONDARY



Interproximal Caries

(Incipient)

I

Up to half the thickness of enamel

Usually not r estor ed unless patient has high

level of caries activity (high risk). Tr eat

with fluoride.



The arrow points to incipient lesions on the mesial of #

19 and the distal of # 20.



Incipient

Moderate

Advanced



The bottom arrow points to a moderate lesion on the

distal of # 20. The upper arrow points to one of several

incipient lesions on the molar and pr emolars.



Moderate lesion seen on pr evious film



Class III moderate lesion seen in the anterior

r egion



Advanced lesion identified by arrows.



Advanced lesions seen on pr evious film



Advanced lesion



Sever e lesion



Occlusal caries



Lingual caries (Can¶t tell whether it¶s buccal or

lingual from one radiograph



Buccal caries with sever e interproximal caries on

# 12



Root caries



Radiolucency seen at left (arrow)disappears on periapical film of same

tooth. This is cervical burnout.



Cervical burnout in the anterior r egion due to gap

between enamel (r ed arrows)

and alveolar bone over root

(blue arrows).



R ecurr ent caries



Rampant Caries

Extensive and rapidly progr essing cariesusually found in childr en and teens with

poor diet and inadequate oral hygiene



Found in head/neck radiation therapy

patients with xerostomia

Fluoride used for control

Radiation Caries



Befor e radiation



1 year after radiation



Dental restorations

are not the treatmentfor dental caries !!!!!!

Why



Cavity Design

Obj ti f it d i



Objectives of cavity design -Remove the caries. -Leave the tooth strong . -Minimal stresses must be placed upon the restorative

material.

Keep occlusal forces upon enamel rather upon restorativematerial.Reproduce the correct contour of the tooth.

Retain maximum dentine . Minimize the cutting mania .

Try to make life easier to the next dentist by leaving much sound tooth substance to correct any furtherfailure . This is fair ; because the next dentist could

be you again ;

Factors determines cavity design



Factors determines cavity design - The structure and properties of dental tissues;

± - unsupported enamel ± - thin and / or weak enamel

± - dentine

± - cementum

± -pulp (size ,shape ..etc.)

-The disease - e.g.

± - caries

± - tooth wear.

± - periodontal disease.

-The properties of the restorative material:

± - if the r estorative material will be supported by the tooth .

± -or the filling will support the tooth.

± -which material to use .



Principles of Cavity Design

1- Access to caries:

Remove least amount of enamel and

dentine to visualize the lesion Precise the buccolingual position of caries

Marginal ridge retain; Or remove

Lingual access if aesthetics is important

Use the already present cavity opening to

reserve sound tooth structure



Accessibility and visibility are

important basic factors




2- Removal of caries is determined by:

Size Size

ShapeShape

Position of cariesPosition of caries




3- Removal of undermined enamel:

is a must if amalgam or is a must if amalgam or gold inlaygold inlay willwill

be used ; be used ;

ButBut if anif an adhesive r estorationadhesive r estoration will be will be

inserted this undermined enamelinserted this undermined enamel cancan be r etained be r etained if it is not weak if it is not weak




4-Develop final cavosurface angle:A- The angle de pends in part upon the:

Orientation of enamel prisms

B- The angle must never be less than 90 degr ees for amalgam, Can be > than 90 degr ees if:

Gold inlay R.M Adhesive r estoration

In the cervical ar ea because the enamel prisms tend to run apically




Principles of Cavity Design4-Develop final cavosurface angle:




5 -- Gingival margins (incr ease No. failur e)

Use (trimmers , Chisel) to remove weak

and unsupported enamel

Correct cavosurface angle must be

maintained

Respect the adjacent tooth




6-Extension of the cavity

1-determined by accessibility and esthetics

2-Can be minimized by using Small cutting

instruments3- Can be aff ected The material that will be used



Small instrument that will adapt the

filling material to the cavity

The use of magnification will r esult in

pr ecise and small cavity The ability of the patient to maintain oral

health conditions



Principles of Cavity DesignPrinciples of Cavity Design

7 - R esistance from (tooth or r estoration)

Weak cusps must be r emoved

R emove undermined ,thin ,and/or weak

enamel

If the tooth will support the filling ,the

r esistance form must be check ed



Cavity Design for Re-restoration

Identify the cause of failure Use the cutting instrument near the bulk of

the restorative material rather than the cavity

wall , So less destruction of the tooth

substance is done



Future of Cavity Design

Hopes that the progress of adhesive dentistry

will: Eliminate to some extent the need of cavity

r etentive design

Incr ease the longevity of r estorations

Simplify the technique of placement



Failure of Restorations

New disease :

Caries and tooth wear

pulpal problems Trauma

periodontal disease

Technical failur e :

Fractur ed r estorations

Marginal br eak down Tooth fractur e

Def ective contour

A ppearance

Failur e of r etention

Factors Produce Weak amalgam



Factors Produce Weak amalgamRestoration

Undertrituration

Too high mercury contentToo low condensation pressure

Slow rate of packing

Corrosion



Tooth fracture

Weak ened tooth structur e R esidual caries

Weakened tooth structure



Weak ened tooth structur e ± cuspal fractur e

Weakened tooth structure



Weak ened tooth structur e ± cuspal fractur e



R esidual caries

± Enamel fractur e

R t i



Recurrent caries

Replacement due to recurrent

caries

Amalgam in adults

72%

Amalgam in children56%

Composites

43%

I.Mjor, Oper Dent, 1985

R t i



Recurrent caries

Poor matrix technique

Recurrent caries



Recurrent cariesPoor condensation

G A l F t



Gross Amalgam Fracture

Shallow preparations

Tensile str ength (MPa)

Amalgam 60

K 170

K1 30

K2 20

G A l F t




Non-retentive proximal boxes





Slow setting alloy

Compressive strength

(MPa)

1hr 24hrs

Amalcap F 94 410

Amalcap SAS 138 435

Permite C 193 448

M i l b kd



Marginal breakdown

Wrong cavo-surface angle

Over fillingUnder filling or over carving

Delayed expansion

Corrosion

i l b kd



Marginal breakdownWrong cavo-surface angle

M i l b kd



Marginal breakdownOver filling

M i l b kd



Marginal breakdownUnder filling or over carving

M i l b kd



Marginal breakdown

Delayed expansion due to contamination

Zn +H2O p ZnO + H2

Marginal breakdown



Marginal breakdown

Corrosion

Marginal breakdown



Marginal breakdown



Tooth wear Tooth wear

The common causes of tooth wear



1-E

rosion: (

most common and most damaging )Regurgitation erosion :

aff ect commonly the palatal surfaces of the upper anterior teeth ,the buccal and occlusal surfaces of the lower

posterior teeth . Caused by the r egurgitation of hydrochloric acid from the stomach in patient with:

Various digestive disor ders ( hiatus hernia,chronic

indigestion)

- Anor exia and bulimia nevrosa- Chronic alcoholism

- Morning sickness ( pr egnancy)

- Voluntary r egurgitation




cont .Erosion

-Dietary erosion :

commonly affect the labial surfaces of the upper anteriorteeth . Caused by excess of food and drink with a low pHincluding :

Citrus and other fruits and fruit juicesPickles and other food and drink containing vinegarCarbonated drinks (carbonic and other acids )

- Industrial erosioncommonly affect the labial surfaces of the upper teeth and

may cause pitting . Caused by industrial processes whichproduce acid fumer or droplets




Attrition A physical wear of one tooth against other . Affect- occlusal surfaces of opposing teeth

- May be accelerated by erosion

- or may be caused entirely by bruxism or otherPara functional activities

Abrasion : Commonly affect the necks of the buccalsurfaces of the anterior and posterior teeth .

Caused by physical wear from external agent such

as : - Abrasive toothpaste and powder- Hard toothbrushes or excessive use of other

cleaning aids- Habits( as thread biting and pipe smoking)

Dental TraumaDental Trauma



Dental TraumaDental TraumaAccidental damage has one of the

following effects.

Fracture involving enamel only

F

racture involving dentineFracture involving enamel, dentine and pulp

Root Fracture

Cracks in the crown without loss of enamel

No visible damage but damage to the pulp orits blood supply, leading to pulp necrosis

Partial or complete luxation of the tooth.

D t l t i l h i



Dental materials choices



Dental AmalgamDental Amalgam



OverviewOverview

Basic composition

Basic setting r eactions

Classifications Variables in amalgam

performance



HistoryHistory

1833

± Crawcour brothers introduceamalgam to US

powder ed silver coins mixed with mercury ± ex panded on setting

1895

± G.V. Black develops formula

for modern amalgam alloy 67% silver, 27% tin, 5% copper, 1% zinc

± overcame ex pansion problems

A lA l



Amalgam Amalgam

An alloy of mercury with another metal.



Why Amalgam?Why Amalgam?

Inex pensive

Ease of use

Proven track r ecor d

± >100 years

Familiarity

R esin-fr ee

± less allergies than composite

Click here for Talking Paper



Constituents in AmalgamConstituents in Amalgam

Basic

± Silver

± Tin

± Copper

± Mercury

Other

± Zinc ± Indium

± Palladium

Amalgam



gConventional alloys.

Contain the following principalConstituent

Silver 64-74%Copper 0 - 6 %

Tin 25 - 27%

Zinc 0 - 2 %

Some alloys contain or have

contained up to 2-3% mercury

Amalgam



gCopper enriched alloys

Blended ( lathe cut 2 and spheres 1 )

Silver 69% Copper 13 %Tin 17 % Zinc 1 %

Basic ConstituentsBasic Constituents



as c Co s ue sas c Co s ue s

Silver (Ag)

± incr eases str ength

± incr eases ex pansion

Tin (Sn) ± decr eases ex pansion

± decr eased str ength

± incr eases setting time

Phillip¶s Science of Dental Materials 2003




Copper (Cu)

± ties up tin

r educing gamma-2 formation


± r educes tarnish and corrosion

± r educes cr ee p

r educes marginal deterioration






Mercury (Hg) ± activates r eaction

± only pur e metal that is liquid at room temperatur e

± spherical alloys

r equir e less mercury ± smaller surface ar ea easier to wet

40 to 45% Hg

± admixed alloys r equir e mor e mercury

± lathe-cut particles mor e difficult to wet

45 to 50% Hg

Click here for AD A Mercury

Hygiene Recommendations


Other ConstituentsOther Constituents



Zinc (Zn) ± used in manufacturing

decr eases oxidation of other elements

± sacrificial anode

± provides better clinical performance less marginal br eak down

± Osborne JW Am J Dent 1992

± causes delayed ex pansion with low Cu alloys

if contaminated with moistur e during condensation ± Phillips RW JADA 1954


H2O + Zn ZnO + H2





Indium (In) ± decr eases surface tension

r educes amount of mercury necessary

r educes emitted mercury vapor

± r educes cr ee p and marginal br eak down


± must be used in admixed alloys

± example Indisperse (Indisperse Distributing Company)

± 5% indium

Powell J Dent Res 1989

O CO C




Palladium (Pd)

± r educed corrosion

± gr eater luster

± example

Valiant PhD (Ivoclar Vivadent)

± 0.5% palladium

Mahler J Dent Res 1990

Basic CompositionBasic Composition



Basic CompositionBasic Composition

A silver-mercury matrix containing filler particlesof silver-tin

Filler (bricks)

± Ag3Sn called gamma

can be in various shapes

± irr egular (lathe-cut), spherical,or a combination

Matrix

± Ag2Hg3 called gamma 1

cement ± Sn8Hg called gamma 2

voids


B i S tti R tiB i S tti R ti



Basic Setting ReactionsBasic Setting Reactions

Conventional low-copper alloys

Admixed high-copper alloys

Single composition high-copper alloys

C ti l LC ti l L C AllC All



Dissolution and pr ecipitation

Hg dissolves Ag and Sn

from alloy Intermetallic compounds

formedAg-Sn

Alloy

Ag-Sn

Alloy

Ag-Sn Alloy

Mercury

(Hg)

Ag

AgAg

Sn

Sn

Sn

Conventional LowConventional Low--Copper AlloysCopper Alloys

Hg Hg

Ag Ag33Sn + HgSn + Hg Ag Ag33Sn + AgSn + Ag22HgHg33 + Sn+ Sn88HgHg


K K K1 K2

Con entional LoCon entional Lo Copper Allo sCopper Allo s




Gamma (K) = Ag3Sn

± unr eacted alloy

± strongest phase and corrodes the least

± forms 30% of volume

of set amalgam

Ag-Sn

Alloy

Ag-Sn

Alloy

Ag-Sn Alloy

Mercury

Ag

AgAg

Sn

Sn

Sn

HgHg

Hg



K K K1 K2

C ti l LC ti l L C AllC All




Gamma 1 (K1) = Ag2Hg3

± matrix for unr eacted alloy

and 2nd strongest phase ± 10 micron grains

binding gamma (K)

± 60% of volume

K1



K K K1 K2

Ag-Sn Alloy

Ag-Sn

Alloy

Ag-Sn

Alloy




Conventional LowConventional Low Copper AlloysCopper Alloys

Gamma 2 (K2) = Sn8Hg

± weak est and softest phase

± corrodes fast, voids form

± corrosion yields Hg which

r eacts with mor e gamma (K)

± 10% of volume

± volume decr eases with time

due to corrosion



K K K1 K2

K2

Ag-Sn Alloy

Ag-Sn

Alloy

Ag-Sn

Alloy

Admixed HighAdmixed High--Copper AlloysCopper Alloys



Admixed High Admixed High Copper AlloysCopper Alloys

Ag enters Hg from Ag-Cuspherical eutectic particles

± eutectic an alloy in which the elements ar e

completely soluble in liquid solution but se parate into distinctar eas upon solidification

Both Ag and Sn enter Hg fromAg3Sn particles


Ag Ag33Sn + AgSn + Ag--Cu + HgCu + Hg Ag Ag33Sn + AgSn + Ag--Cu + AgCu + Ag22HgHg33 + Cu+ Cu66SnSn55

K K K1 L

Ag-Sn

Alloy

Ag-Sn

AlloyMercury

AgAg

Ag

SnSn

Ag-Cu Alloy

AgHgHg

Cl ifi tiCl ifi ti



ClassificationsClassifications

Based on copper content

Based on particle shape

Based on method of addingcopper

Copper ContentCopper Content



Copper ContentCopper Content

Low-copper alloys

± 4 to 6% Cu

High-copper alloys

± thought that 6% Cu was maximum amount

due to f ear of excessive corrosion and ex pansion

± Now contain 9 to 30% Cu

at ex pense of Ag


Particle ShapeParticle Shape



Particle ShapeParticle Shape

Lathe cut ± low Cu

New True

Dentalloy

± high Cu A NA 2000

Admixtur e

± high Cu

Dispersalloy, Valiant PhD

Spherical ± low Cu

Cavex SF

± high Cu

Tytin, Valiant

M t i lM t i l R l t d V i blR l t d V i bl



MaterialMaterial--Related VariablesRelated Variables

Dimensional change

Str ength

Corrosion

Cr ee p

Dimensional ChangeDimensional Change



Dimensional ChangeDimensional Change

Most high-copper amalgams undergo a net

contraction

Contraction leaves marginal gap

± initial leakage

post-operative sensitivity

± r educed with corrosion over time


StrengthStrength



StrengthStrength

Develops slowly

± 1 hr: 40 to 60% of maximum

± 24 hrs: 90% of maximum

Spherical alloys str engthen faster

± r equir e less mercury

Higher compr essive vs. tensile str ength

Weak in thin sections ± unsupported edges fractur e


Amalgam PropertiesAmalgam Properties



Amalgam Properties Amalgam Properties

Compressive

Strength (MPa)

% Creep Tensile Strength

(24 hrs) (MPa)

Amalgam Type 1 hr 7 days

Low Copper 1 145 343 2.0 60

Admixture2 137 431 0.4 48

Single

Composition3

262 510 0.13 64


CorrosionCorrosion



CorrosionCorrosion

R educes str ength

Seals margins

± low copper

6 months ± SnO2, SnCl

± gamma-2 phase

± high copper

6 - 24 months ± SnO2 , SnCl, CuCl

± eta-phase (Cu6Sn5)

Sutow J Dent Res 1991

CreepCreep



CreepCreep

Slow deformation of amalgam placed under aconstant load

± load less than that necessary to produce fractur e

Gamma 2 dramatically aff ects cr ee p rate ± slow strain rates produces plastic deformation

allows gamma-1 grains to slide

Corr elates with marginal br eak down


CreepCreep



pp

High-copper amalgams have cr ee p r esistance ± pr evention of gamma-2 phase

r equir es >12% Cu total

± single composition spherical

eta (Cu6Sn5) embedded in gamma-1 grains ± interlock

± admixtur e

eta (Cu6Sn5) around Ag-Cu particles

± improves bonding to gamma 1

Click here for table of creep values

DentistDentist Controlled VariablesControlled Variables



DentistDentist--Controlled VariablesControlled Variables

Manipulation

± trituration

± condensation ± burnishing

± polishing

TriturationTrituration



TriturationTrituration Mixing time

± r ef er to manufactur er r ecommendations Click her e for details

Overtrituration ± ³hot´ mix

sticks to capsule

± decr eases working / setting time

± slight incr ease in setting contraction Undertrituration

± grainy, crumbly mix


CondensationCondensation



CondensationCondensation

Forces ± lathe-cut alloys

small condensers

high force

± spherical alloys

large condensers

less sensitive to amount of force

vertical / lateral with vibratory motion

± admixtur e alloys

intermediate handling between lathe-cut and spherical

BurnishingBurnishing



BurnishingBurnishing

Pr e-carve

± r emoves excess mercury

± improves margin adaptation Post-carve

± improves smoothness

Combined ± less leakage

Ben- Amar Dent Mater 1987

PolishingPolishing



PolishingPolishing

Incr eased smoothness

Decr eased plaque r etention

Decr eased corrosion

Clinically eff ective?

± no improvement in marginal integrity

Mayhew Oper Dent 1986 Collins J Dent 1992

± Click her e for abstract



Revised: July 2008

Dental amalgam (silver filling) is consider ed a safe, affordable and

durable material that has been used to r estor e the teeth of mor e than 100

million Americans. It contains a mixtur e of metals such as silver, copper

and tin, in addition to mercury, which binds these components into a har d,

stable and saf e substance. Dental amalgam has been studied and

reviewed extensively, and has established a record of safety and

effectiveness.

ADA Positions & Statements

ADA Statement on Dental Amalgam

ADA Council on Scientific Affairs Amalgam Saf ety Update

Se ptember 2010

LITERATURE REVIEW: DENTAL AMALGAM FILLINGS AND



The findings of the studies published between January 1, 2004

and June 15, 2010 showed no consistent evidence of harm

associated with dental amalgam fillings, including for infants and childr en

Ther e was no evidence demonstrating that some individuals ar e

genetically susce ptible to harmful eff ects from ex posur e to the

low doses of mercury associated with dental amalgam fillings.

Overall, studies continue to support the position that dentalamalgam is a safe restorative option for both children and

adults. When r esponding to saf ety concerns it is important to

mak e the distinction between known and hypothetical risks.

LITER ATUR E R EVIEW: DE NTAL AMALGAM FILLINGS A ND

HEALTH EFFECTS

Dental Amalgam ADA Statement 2010

Overview



Dental amalgam (or "silver-color ed filling") is a durable metal alloy

comprised of silver, copper and tin, in addition to mercury, which binds

these components into a har d, stable substance. It has been used to

saf ely r estor e the teeth of mor e than 100 million Americans.

Dental amalgam has a strong r ecor d of saf ety, which the scientificcommunity has extensively r eviewed and affirmed. Mor eover, the ADA

encourages dental offices to follow its Best Management Practices for

Amalgam Waste, which will help r educe any eff ects of amalgam waste

on the environment.

Amalgam safety. The ADA r ecognizes dental amalgam (silver-color ed

filling) as a safe and effective restorative material and will oppose

efforts to ban or otherwise restrict its use.

.

ADA STATEMENT 2010 Dental Amalgam Overview cont«

Informed choice. The ADA believes that patients and their dentists should have



access to the full range of saf e and eff ective options for tr eating dental decay.

Amalgam separators. The ADA encourages dentists to comply with its best

management practices which include the r ecycling of waste amalgam in the

dental office and the voluntary use of amalgam se parators.

FDA device classification. The ADA commends the FDA's decision finding

dental amalgam to be a saf e tr eatment option and agr ees with its decision toclassify encapsulated amalgam as a Class II medical device, the same

classification as for gold inlays and tooth-color ed composite fillings.

Continued research. The ADA welcomes calls for additional r esearch to ensur e the prof ession and the public have the most curr ent, scientifically valid

information on which to base tr eatment decisions involving r estorative materials.

Matrix Systems for Matrix Systems for



Restorative DentistryRestorative Dentistry

IntroductionIntroduction



A matrix system provides and takes the place of the proximal t ooth surf ace that was removed t o rest ore the proximal cont ours and contact t o their normal shape and funct ion.

Posterior Matrix SystemPosterior Matrix System



Universal retainer Also referred t o as the Tofflemire retainer.

This device holds the mat rix band inposit ion. The retainer is posit ioned most

commonly from the bucal surf ace of the t ooth being rest ored.

Components of a Universal Retainer Components of a Universal Retainer



Posterior Matrix SystemPosterior Matrix System

cont¶dcont¶d



Matrix bands

Mat rix bands are made of flexible stainless st eel and are available in premolar, molar, and universal sizes and thicknesses.

The larger circumference of the band is the occlusal edge and is always placed t oward the occlusal surf ace.

The smaller circumference of the band is the gingival edge and it is always placed t oward the gingiva.

Fig. Fig. 4949--2 2 Types of matrix bands.Types of matrix bands.



WedgesWedges



A wedge is either t riangular or round and made of wood or plast ic.

The wedge is insert ed int o the lingual embrasure t o posit ion the mat rix band firmly

against the gingival margin of the preparat ion.



Fig. Fig. 4949--66 A wedge correctly positioned. A wedge correctly positioned.



Automatrix System Automatrix SystemTh i i l i i l



The aut omat rix syst em is an alt ernat ive t o a universal

retainer. There is no retainer used t o hold the band in place.

Bands are already formed int o a circle and are available in assort ed sizes in both metal and plast ic.

Each band has a coil like aut olock loop.

A t ight ening wrench is insert ed int o the coil and t urned clockwise t o t ight en the band.

When finished, the t ight ening wrench is insert ed int o the coil and t urned count erclockwise t o loosen the band.

Removing pliers are used t o cut the band.

Matrices for CompositeMatrices for Composite

RestorationsRestorations



A plast ic mat rix, also referred t o as acelluloid matrix or mylar strip, is used for class III and IV rest orat ions in which the proximal wall of an ant erior t ooth is missing.



Increasing Retention for largeIncreasing Retention for large



Amalgam Restorations Amalgam Restorations

Why do we need to do this?

LARGE AM ALG AMLARGE AM ALG AM

EST AT SEST AT S



REST

OR AT

IONS

REST

OR AT

IONS

Pin-r etention

Additional r etentive f eatur es

Capping cusps

Objectives



To describe methods of incr easing r etention in amalgamr estorations.

To addr ess the specific concerns of r etention & r esistance form in amalgam r estorations.

To be introduced to the Pin amalgam r estoration, types of pin & terminology.

To describe parameters & clinical ste ps in pin placement.

To introduce the conce pt of Amalgam Bonding Systems

What are the best treatment options

for restoring this tooth?



± Pinned amalgam?

± Bonded amalgam?

± Pinned/Bonded

amalgam? ± Amalgapins?

± Dentin Slots?

± Endodontics/Post/Cor e

then PFM crown? ± Composite r esin?

Methods for Increasing Retention



Offset Boxing Dentin Slots

Amalgapins

Proximal R etention Grooves

Pins

± Cemented

± Friction -lock ed

± Self-thr eading

Bonded Amalgam R estorations

Offset Boxing



g

Pr e parations which

include additional

boxing with r etentive opposing walls add to

the r etention of an

amalgam r estoration

Dentin Slots or Troughs



Used as an alternative to pins for additional r etention R etention has been shown to be comparable to pinned

amalgams using thr eaded pins

Slots ar e formed by using an inverted cone bur 33 1/2, 34or 35 to produce a continuous slot in the gingival floor at a ± Depth of 0.6mm

± Width of 0.5 mm at the floor

± Width of 0.6mm at the base

Extr eme car e must be tak en to avoid movement of the matrix during condensation

Slot(s) must be in dentin

Ideally should be 1.0 mm from the DEJ

Ideally should be 1.0 mm from the external aspect of the tooth



33 133 1//2 2 inverted cone burinverted cone bur



for gingival grooves thatfor gingival grooves that

must be totally in dentinmust be totally in dentin

##11 round bur forround bur for

countersink countersink

Amalgapins Use a 1156 1157 56 or 330 bur



Use a 1156, 1157, 56 or 330 bur

± Width of 0.8 mm ± De pth of 2.0 mm

Entrance to channels ar e beveled

Comparable to r etention of thr eaded pins

Shavell, HM, J Calif Dental Assoc

1980; 8:48-55

Not used as much clinically due toadvances in clinical bonding of r estorations.

Examples:



p

Tooth r estor ed with

amalgampins (upper

first molar)

Tooth r estor ed with

thr eaded pins Lower first molar

Proximal Retention Grooves



Place entir ely in dentin

Located at the axio-

buccal and axio-lingual

line angles

Utilized when proximal

box extends bucco-

lingually beyond idealextensions

Pins



Pins

Cemented pins

Friction locked pins

Threaded pins

In clinic, only thr eaded

pins (either minikin or minim pins) ar e used

Types of Pins



Cemented Friction-lock ed Self-thr eading

Cemented Pins



1958 Miles Markley

serrated stainless steel

pins

pinholes larger than the

pin by 0.025-0.050 mm cemented with zinc

phosphate or

polycarboxylate cement

pinhole de pth 3.0-4.0 mmdee p

Advantages

no internal stress

lines or crazing

Di sadvantages

pulpal irritation due tozinc phosphate cement

microleakage

least r etentive of all typesof pins

Types of Pins




Friction-lock Pins



1966 Goldstein

diameter of pinhole is

0.025 mm smaller than the

diameter of the pin

pinhole should be 2.0-4.0

mm dee p

Advantages

2-3X mor e r etentive thancemented pins

Di sadvantages str ess and cracking of

dentin

difficult to place wher e access is limited

microleakage minimal r etention

Types of Pins




Self-threading Pins



1966 Going

diameter of pinhole is

0.038-0.10 mm

smaller than the pin

r etained due to the

r esilience of dentin

de pth of pinhole is 2.0mm

Advantages

most r etentive of all

pin types (5-6X mor e

r etentive than

cemented pins)

Di sadvantages str ess and cracking of

dentin (mor e than

friction-lock ed pins)

Guidelines for Pin Placement



Pins must be placed

parallel to the external

surface of the tooth

Proper Pin Placement



Guidelines for Pin

Placement



Place pins at the line angles of the tooth

Avoid furcations

Must have minimum of 0.5 mm of amalgamsurrounding the pin

Pin must be 1.0 mm fromthe DEJ

Pin must be 1.0 mm fromthe external surface of the tooth



Is ther e enough room

to place any pins in

pr emolars or anterior

teeth?

Guidelines for Pin Placement:



1. Initiate pin placement

with a ³starter hole´

using a 1/4 or 1/2

round bur

What is the purpose of

this step???

Guidelines for Pin

Placement«



2. Place pin drill bur (Latch)

into slow speed (Contra-

angle) Check alignment

of hand piece with the pin.

Align with external


What is the purpose of the

above procedures?

Examples of Pin Placement &

Pin Bending



g

How well ar e these

pins placed?

Can amalgam be

condensed around each of them?

Ar e they 1.0 mm from

the DEJ?

Ar e they 4.0 mm

apart?



Self-limiting vs non

self-limiting drills

Example of Poor Pin Placement



Alignment is with the external


± Not with adjacent crown

± Not with existing crown

Don¶t lose orientation when

under rubber dam

Use the cervical portion of the

tooth to align the pin drill bur

with the tooth



Minim pins should be

± 2 mm in tooth

± 2 mm in r estoration

PIN SITES:PIN SITES: zz PrimaryPrimary ||SecondarySecondary ÁÁDangerDanger



ÁÁÁ

y



Tak e car e in bending pins

May r esult in fractur ed

tooth if performed improperly

Use pin bender and support base with

cotton pliers or hemostat to pr eventfracturing the tooth

Poor Pin Placement



Consequence of improper pinorientation

± P

DL perforation

± Long-termramifications of PDL

perforation ?

± Long-termramifications of pulpal

perforation with pin?

Guidelines For Threaded Pin

Placement



Minimum of 1.0 mm from

external surface of tooth

Minimum of 1.0 mm from

DEJ

Use 1 pin for each axial

surface r e placed

Use 1 pin for linear 4.0

mm of tooth structur e

Consider horizontal pin placement wher e possible

Place parallel to externalsurface of tooth

2 mm in tooth/ 2 mm intor estoration (Minim)

Place pins at line angles of tooth

Avoid furcations

Minimum of 0.5 mm of

amalgam must surround pin

Bonded Amalgams



Amalgambond® (Parkell) ± self-curing dentin bonding agent (4-META*-

containing adhesive r esin)

the question at this time is that the longevity of the bond is undetermined Not used clinically as much due to the number of

ste ps involved with the bonding system. Simpler systems exist & ar e easier to use

Purpose of Bonded Amalgam R estorations?

Amalgam Bonding Systems



Amalgambond

All-Bond II Bonding System



All-Bond II® (Bisco)

± dual-cur e universal bonding system

± mixed Primer A (NTG GMA in acetone) and

Primer B (BPDM in acetone)

± adhesive is composed of Bis GMA + HEMA

Resinomer Bonding System



Resinomer

Used in the clinic

Resinomer (Bisco)



A dual-cur ed, glass filled, fluoride-r eleasingcomposite with viscosity and flow which mak e itideal for bonded amalgam r estorations, as a dental

liner and luting cement.

Insoluble in oral fluids and exhibits low thermalconductivity -- good characteristics for a liner or

base. High str ength adhesive seal to dentin

Alloybond Bonding System



Alloybond

Used in the clinic

Ease of use. Simple,few steps.

Good clinical track

record!

Alloybond



A high str ength fluoride r elease amalgam

bond.

Unique dimethacrylate r esin groups provide twice the cross linking and superior str ength.

Does not contain Bis GMA nor BisPhenol A



GlassGlass IonomersIonomers && CompomersCompomers

OverviewOverview



Glass ionomers ± composition

± properties

± classification Compomers

± composition

± properties

Giomers

Traditional Cements



Zinc PhosphateZinc Phosphate PolycarboxylatePolycarboxylate

SilicateSilicate Glass Ionomer Glass Ionomer

Phosphoric acidPhosphoric acid Polyacrylic acidPolyacrylic acid

Zinc OxideZinc Oxide

Aluminosilicate Aluminosilicate

GlassGlass

Van Meerbeek Fund

Oper Dent 2001

GlassGlass Ionomer Ionomer DevelopmentDevelopment



United Kingdom ± Wilson and K ent

1972

ASPA

± first commercial product

± alumino-silicate polyacrylic acid

± combined benefits

silicates ± translucency, fluoride r elease

polycarboxylates

± adhesion, biocompatibility

Tyas J Adhes Dent 2003

Early GlassEarly Glass IonomersIonomers



Poor esthetics

± rough surface

Prolonged setting r eaction

Poor wear r esistance

Vulnerable to hydration extr emes

Handling difficulties

Van Meerbeek Fund

Oper Dent 2001

ModificationsModifications



R efined formulation

± addition of tartaric acid

± mor e r eactive acids

Improved packaging

Metal modification

Addition of r esin

Van Meerbeek Fund

Oper Dent 2001

Advantages Advantages



Inher ent (chemical) adhesion to toothstructur e

Fluoride r elease

Coefficient of thermal ex pansion (CTE)similar to tooth structur e

Biocompatible

Van Meerbeek Fund

Oper Dent 2001

DisadvantagesDisadvantages



Sensitive to moistur e and desiccation

Low fractur e toughness

Low flexur e str ength Low wear r esistance

R elatively poor esthetics

Van Meerbeek Fund Op

IndicationsIndications



Dir ect r estorative

± Class 5

± Root caries

± Class 3 ± Pediatric dentistry

r esin-modified version

± Tunnel pr e parations

± Atraumatic r estorative tr eatment (ART)

Van Meerbeek Fund O




Luting agents

Liners

Caries control

Cor e block-out

Occlusal sealant

Van Meerbeek Fund Oper

Dent 2001

ContraindicationsContraindications



Str ess-bearing ar eas in permanent teeth

± Class 1, 2 and 4

Basic GlassBasic Glass Ionomer Ionomer TypesTypes



Conventional GI

± traditional acid-base r eaction

R esin-modified (R MGI) ± acid-base r eaction

± light and/or chemical cur e

Conventional GlassConventional Glass Ionomer Ionomer



Composition ± powder

ion-leachable calciumaluminofluorosilicate glass

± liquid copolymers of acrylic acid

and/or

water

± copolymers fr eeze-dried, placed in powder maximize shelf-lif e

Phillip¶s Science of Dental

Conventional GlassConventional Glass Ionomer Ionomer



Ion-leachable glass

± silicon dioxide

± aluminum oxide

± calcium fluoride

± aluminum phosphate

± sodium fluoride

± aluminum fluoride


Materials 2003

Conventional Glass Ionomer Conventional Glass Ionomer



Polyacids ± acrylic

± maleic

± itaconic

± tricarboxylic acid

Tartaric acid

± improves handling

± extends working time ± sharpens set

± incr eases str engthPhillip¶s Science of Dental

ResinResin--Modified Glass IonomersModified Glass Ionomers



First developed as liners

Modified light- and/or chemically-activated

methacrylate side chains ± on polyacrylic-acid molecules

± fr ee in solution

HEMA

Total set r esin 4.5 - 6%

ResinResin--Modified Glass Ionomer Modified Glass Ionomer

Attempt to combine Attempt to r educe



benefits

± glass ionomer

fluoride r elease

adhesion

± composite r esin

str ength

esthetics

± glass ionomer

hydration sensitivities

delayed set

poor early str ength

± composite polymerization shrinkage

microleakage

r ecurr ent caries

Glass Ionomers RMGI Compomers Composites

ResinResin--Modified Glass Ionomer Modified Glass Ionomer



Composition ± powder

ion-leachable glass

± liquid

initiators copolymers of acrylic acid

± methacrylate groups graftedand/or HEMA

± and/or

water

± copolymers fr eeze-dried, placed in powder

maximize shelf-lif e


MaterialMaterial--Related VariablesRelated Variables



Fluoride r elease

Adhesion

P

ulpal r esponse Physical Properties

Adhesion to Tooth Structure Adhesion to Tooth Structure

C i l GI COO

C 2



Conventional GI ± ion exchange

GI ± tooth substrate

± carboxyl groups of GIC

bond with Ca+2 of hydroxyapatite

R esin-modified GI

± ion exchange similar to conventional GI

± r esin-impr egnated hybrid layer ? equivocal

Wilson JDR

1983

M3+

COO-

COO-

COO-

COOH

COO-

COO-

COO-

COO-

Ca2+

Ca2+

Too

th

Pulpal ResponsePulpal Response



Favorable

± large molecules

limited tubule ingr ess

± buff ering of dentinal fluid ± r elatively weak acid

initial high acidity

± chemical adhesion

minimizes microleakage ± antimicrobial activity

Burgess Fund Oper

Dent 2001

Property GI RMGI Comp

omer

Comp

ositeFlexural Strength (MPa) 15-25 35-70 60-94 85-97

Compressive Strength (MPa) 170-200 180-210 190-250 230-270



Diametral Tensile Strength

(MPa)22-25 35-40 45-47 40-60

Fluoride Release High High Moderate Minimal - None

Fluoride Recharge

High H

igh Moderate Minimal - None

Burgess Fund Oper Dent 2001


Strength

Polishability

Fluoride Release

ClassificationsClassifications A pplications

± Type 1: luting cements



± Type 2: r estorative cements

esthetic r estoratives

r einforced r estoratives

± condensable

± metal-modified

± Type 3: liners/sealants

Chemistry ± conventional GI

traditional acid-base r eaction

± r esin-modified (R MGI)

acid-base r eaction

light and/or chemical cur e

Orthodontic Luting AgentsOrthodontic Luting Agents

Fl id l i



Fluoride r eleasing ± r educed incidence of white spot lesions

Benson J Ortho 2005

Bonds in moist environment

Condition surface ± etch optional

Only light-leveling wir es first 24 hrs

Examples

± Fu ji Ortho (GC) ± Fu ji Ortho LC (GC)

Endodontic ObturationEndodontic Obturation



Fluoride r eleasing

Radiopaque

Short working time

Mor e difficult to r etr eat

Example

± K etac-Endo (3M EPSE)

Buck Gen Dent 2002

Esthetic RestorativesEsthetic RestorativesFinishingFinishing



Conventional GI

± surface coat

± wait 15 minutes

± minimize trauma

to surface

use blades

slow speed

Esthetic RestorativesEsthetic RestorativesFinishingFinishing



R MGI

± surface coat

± immediate finishing

± normal armamentarium

fine diamond

polishing discs

± gentle technique

Esthetic RestorativesEsthetic RestorativesSurface ProtectionSurface Protection

Protect setting cement

l i i i



± early moistur e contamination

± desiccation later

Unfilled r esins

± essential conventional

± optional

R MGI

± mor e r esistant to water loss ± fills irr egularities

± color stability

± decr eased F r elease

Summitt Fund

Esthetic RestorativesEsthetic Restoratives

RMGIRMGI LinersLiners

P t i it



Posterior composite ± ³open-sandwich´ technique

± dentinal gingival margins

r educed leakage r educed gap formation

± examples

Fu ji II LC (GC)

Vitr emer (3M ESPE)

Burgess JDR

1999 Hagge

Compomers in DentistryCompomers in Dentistry



Dir ect r estorations

± r estoratives

± flowables

Cements

Advantages Advantages

E t l d li h



Easy to place and polish Some fluoride r elease

Mor e esthetic than glass ionomer

Better mechanical properties than glassionomer

el-Kalla Oper


DisadvantagesDisadvantages Inf erior mechanical properties

d i



± compar ed to composite

Yap Oper Dent 2004

± click her e for details

Less fluoride r elease than glass ionomer ± minimal r echarge

No chemical bond to tooth structur e

el-Kalla Oper



Esthetics



Esthetics

Ar eas of lower str ess

± class 5, 3

± pediatric conservative class 1 and 2

Folwaczny Am J

Dent 2001 Van

Di ken Am J Dent

Click here for more details

ContraindicationsContraindications

Stress bearing areas



Str ess-bearing ar eas

± permanent Class 1 or 2

incr eased wear

± Wucher Am J Dent 2002

click her e for details

loss of marginal integrity

± Huth Am J Dent 2004

click her e for details

Poor isolation

Burgess Fund

GiomersGiomers

R esin-based r estoratives

P t d l i ti l (PRG)



Pr e-r eacted glass-ionomer particles (PRG)

± fillers from conventional GI r eaction

Fr ee-radical polymerization r eaction

± similar to light-activated r esin composites

No chemical bond to tooth structur e

Mor e r esearch needed

Example ± Beautifil (Shofu)



Adhesive Restorations



Bonding to Enamel



Is a clinically wellestablished

technique with

outstanding resultssince early 1970¶s

Bonding to dentinBonding to dentin

(difficulties )



Dentine is a vital tissue

Has an inorganic material ( 70% by Wt)

Has an organic material (20% by Wt)

F

illed with water (hydrophilic) needshydrophilic monomer (not as enamel bond)

The pr esence of the Smear layer

Dentine smear layer (SL)

The presence of the SL was



The presence of the SL wasfirst suggested by Skinner(1961)

(Adhesive restorative dental materials p 6 )

Spencer,Indiana: Owen Litho Service

Described in details by Boydeet al.(1963)

advances in fluorine Resaearch and

dental caries prevention.

( oxford Pergamon press vol I pp185-193)

Dentine smear layer

Definition: the term smear



Definition: the term smearlayer was used to describe alayer of grinding debris lefton dentine surface followingcavity preparation

(E ik et al.1970)

Compostion

Blood

SalivaBacteria

Dentine particles(Br annst rom and J ohnson 1974)

Dentine smear layer

Advantages

A ff i



Acts as an effective

natural liner that seals

the dentinal tubules

and reducespermeability

(Br annst rom, Li nden & Ast rom,

1967) (P ashley et al. , 1978)

(Schulei n , 1988)

Dentine smear layer

DisadvantagesHas been considered to be a site



Has been considered to be a sitewhere bacteria may harbored

(Brannstrom 1982)

A barrier to the adhesion of resinand polyacrylates cements

As( SL) prevent / reduce thepenetration of the resinmonomers to the dentinesurface and intertubulardentine

(Schulei n 1988)

Objectives Of DentineConditioning

I t t f



Is to create a surfacecapable of

micromechanical

and

possibly chemicalbonding to a dentine

bonding system.

AdhesiveInterface 1DENTAL

ADHESION



Adherend 1 Adherend 2

Adhesive Systemor Luting Cement

Interface 2Interface 1 DENTAL

JOINT

ENAMEL, DENTIN >Liner, Base, Cement >

Post and Core >Dental Amalgam >

Implant >

< Composite, Amalgam< Cast Inlay, Onlay, or Crown< All-Ceramic Inlay, Onlay, or Crown< Veneers, Maryland Bridges< Orthodontic Brackets

Scotchbond Multipurpose Plus

3M Dental Products Division

(Ethanol and water solvent system)(Ethanol and water solvent system)



Prime&BondPrime&Bond

Dentsply InternationalDentsply International

(Acetone solvent system)(Acetone solvent system)

Single BondSingle Bond

33M Dental Products DivisionM Dental Products Division

(Ethanol and water solvent system)(Ethanol and water solvent system)

OneOne--StepStep

BISCOBISCO

(Acetone solvent system)(Acetone solvent system)

HOWHOWMUCHMUCH

SOLVENT?SOLVENT?

Designing Bonding SystemsDesigning Bonding Systems

E+nE+nPP++BB

US Companies

E+nE+nPPBB

Japanese Companies

or nEor nEPP++BBSelf Self--EtchingEtching

PrimerPrimer

nEnEPPBBSelf Self--EtchingEtching

AdhesiveAdhesive

Total Etch SystemsTotal Etch Systems



BONDING AGENT

PRIMER

ETCHANT

p

2 =

1 =

p p

= 2

= 1

???hydrophilic tooth structure

hydrophobic ³restorative material

Gluma ® Series And I Bond (Kulzer)(Kulzer)

Gluma ® Solid Bond Gluma ® Comfort

BondGluma ® Comfort

and Desensitizer



I Bond

Steps in Forming Good Adhesion

(1) Clean adherend



(2) Good wetting

(3) Intimate adaptation

(4) Bonding

(5) Good curing physical bondingchemical bondingmechanical

bonding

+ ±

(1) OPERATOR Technical ability Age Eyesight

PERFORMANCE FACTORSPERFORMANCE FACTORS5 5 Categories of Factors Affecting PerformanceCategories of Factors Affecting Performance



( ) Technical ability, Age, Eyesight, ...

(2) DESIGNSL, Bevels, Outline Form, «.

(3) MATERIALSComposition, Product age, T, %RH, ...

(4) INTRAORAL LOCATIONAnterior-Posterior, Maxillary-Mandibular,Lingual-Facial, Premolar-Molar, Tooth Flexure, ...

(5) PATIENTF-exposure, Diet, Oral Hygiene IQ, Caries Risk, ...

E + nE + nPP ++ BB or nEor nEPP ++ BB E + nE + nPPBB nEnEPPBBSelf Self--Etching PrimerEtching Primer

Self Self--Etching AdhEtching Adh

B =B = B =B =



nnP =P =HEMA, « ,HEMA, « ,

(Polymers),(Polymers),Alcohol, HAlcohol, H22O, AcetO, Acet

E =E =HH33POPO44,,

HH22OO

BisBis--GMA, TEGDMAGMA, TEGDMA

Acetone or AlcoholAcetone or Alcohol

E =E =HH33POPO44,,

HH22OO

nnPB =PB =HEMA, « , TEGDMAHEMA, « , TEGDMA

(Polymers),(Polymers),Alcohol, HAlcohol, H22O, AcetO, Acet

MMA, BisMMA, Bis--GMA, TEGDMA,GMA, TEGDMA,

(Polymers),(Polymers),

Acetone or AlcoholAcetone or Alcohol

Acid Monomer,Acid Monomer,

HEMA,HEMA,

HH22OO

nnEP =EP =Acid Monomer,Acid Monomer,

HEMA,HEMA,

Polymer,Polymer,(TEGDMA),(TEGDMA),

HH22O, AlcoholO, Alcohol

nnEP =EP =

E+nE+nPP++BB E+E+nPBnPB nEPnEP++BB

Self Self--EtchingEtchingPrimerPrimer

nEPnEPBB

Self Self--EtchingEtchingAdhesiveAdhesive

TotalTotal--Etch SystemsEtch Systems Self Self--Etch SystemsEtch Systems

h yd rophobi c



Rel i able Bond i ng Rel i able Bond i ng N o Po st oper at i ve S ensi t i vi ty N o Po st oper at i ve S ensi t i vi ty

1. Store in the refrigerator and use quickly.

2. Use steel or carbide burs (not diamonds) for dentinsurfaces to be bonded.

3. Apply multiple layers and agitate applicator.

4. SEPs (and SEAs) should be ³air dried´ >10s, and³not air thinned.´

5. Consider H3PO4 etch, as well, if significant

enamel involved in preparation surfaces.

HybridLayer

HybridLayer

HybridLayer

HybridLayer

h yd rophi l i c

BONDING SYSTEMSBONDING SYSTEMS2-COMPONENT SYSTEMS (nEP + B) Clearfil SE Bond & LinerBond 2v (Kuraray) Tyrian SPE (Bisco) Optibond Solo SE Plus (Kerr) Fluoro Bond (Shofu)

3-COMPONENT SYSTEMS (E + nP + B) Scotchbond Multipurpose Plus (3M) Permaquick (Ultradent) Bond-It (Jeneric / Pentron) All Bond 2 (BISCO)



Fluoro Bond (Shofu) UniFil Bond (GC) Mac Bond II (Tokuyama) NanoBond (Pentron)

1-COMPONENT SYSTEMS (nEPB) AQBond (Sun Medical)

or Touch-and-Bond (Parkell) Adper Prompt or LP3 (3M-ESPE) Solist (One-bottle-bond) (DMG Hamburg) iBond (Hereaus-Kulzer) Xeno III (Dentsply)

All-Bond 2 (BISCO) Tenure A/B/S (Denmat) ProBond (Dentsply)

2-COMPONENT SYSTEMS (E + nPB) Syntac Single Component (Ivoclar) Ecusit Primer/Mono (DMG Hamburg)

One Coat Bond (Coltene /Whaledent) Bond-1 (Jeneric / Pentron) Tenure Quik with Fluoride (Denmat) Solid Bond (Hereaus-Kulzer) Imperva Bond (Shofu) EG Bond (Sun Chemical) PQ1 (Ultradent) Easy Bond (Parkell) Paama 2 and Stae (SDI)

Prime&Bond NT (Dentsply) Single-Bond (3M) Optibond Solo and Solo Plus (Kerr) One-Step (BISCO) Excite (Ivoclar/Vivadent) OSB Bonding System (ESPE) IntegraBond (Premier)

AMALGAMBONDING SYSTEM

Amalgam ReactionProduct Matrix

AMALGAM BONDINGAMALGAM BONDINGMechanical InterlockingMechanical Interlocking



ENAMEL orDENTIN

DENTALAMALGAM

Product Matrix

ResidualAmalgam Alloy

Interfacial Interlocking of phases

Amalgambond Plus

(Parkell)

Composite ResinComposite Resin



What is a composite resin?

O i R i M t i



Organic Resin Matrix

Inorganic Glass Filler

Coupling Agent

The Filler

R educe polymerisation shrinkage



educe po y e s o s ge

R educe coefficient of thermal ex pansion

Improve mechanical properties

Provide radiopacity

± incorporate heavy metals in the glass

barium

strontium

CompositesThe components of modern

composites may be listed:



composites may be listed:Principal monomers

Diluent monomers

Inorganic fillers

Silane coupling agents

Polymerization inhibitors

Initiators / activators

U. V. stabilizer

Proposed Category OfComposite Resins

Macrofilled



Macrofilled

Microfilled

Microfilled - Type

Submicrofilled - type

Hybrid ( macro and micro )

Hybrid - type

Semihybrid

Composite resin

Filler TechnologyTraditional CompositesTraditional Composites



Filler TechnologyFiller TechnologyMicrofilled ResinsMicrofilled Resins



Filler TechnologyFiller TechnologyHybrid Composite ResinsHybrid Composite Resins



Glass particles - 10-40Qm

Colloidal silica - 0.05Qm

Filler TechnologyFiller TechnologyHybrid Composite ResinsHybrid Composite Resins



Glass particle size ~1-10QmGlass particle size ~5-20Qm

Filler TechnologyFiller TechnologySmall Particle Composite ResinsSmall Particle Composite Resins



Glass particles - <1Qm

Colloidal silica - 0.05Qm

Composite resins

Advantages Disadvantages



Advantages

Excellent aesthetics

Command set

Versatile

Clinically proven

g

Non-adhesive

Shrink on setting

Time consuming toplace

Lack strength andtoughness

Susceptible to wear Biocompatible?



Dental Curing LightsDental Curing Lights

Characteristics of LightCharacteristics of Light

Visible light



g

± 400-700 nm

Most composites sensitive

± 400-520 nm (blue)

Photo-initiator in r esin

± absorbs photon energy

± combines with activator

amine

± cr eating fr ee radicals initiates polymerization

PhotoPhoto--polymerizationpolymerization

Camphorquinone (CQ)



Camphor quinone (CQ)

± most common

photo-absorbing material

± maximum sensitivity blue range (465 nm)

VisibleVisible--Light ActivationLight Activation

Photo-initiator reacts with amine activator



Photo initiator r eacts with amine activator

Forms fr ee radicals

Initiates addition polymerization

± monomer

Bis-GMA

Inadequate PolymerizationInadequate Polymerization

Lack of retention



Lack of r etention

Incr eased wear

Color instability

Microleakage

± post-op sensitivity

± caries

Ferracane J Dent R es 1997

Optimal PolymerizationOptimal Polymerization

R equir ed Energy Density



± varies from composite to composite

± based on 2 mm de pth

± based on minimum80% har dness ratio

bottom to top

R equir ed energy density not provided by

most composite manufactur ers!!

Pilo Dent Mater 1992

So, how long should I cure mySo, how long should I cure my

composite?!composite?!R ef er to the manufactur er¶s instructions for guidance



Incr ease curing time

± lower irradiances

LED Halogen

± microfill composites

± dark er shades

± flowable composites ± gr eater distances

± poor collimation

Decr ease curing time

± higher irradiances

P

lasma arc ± hybrid composites

± lighter shades

± close distance

± good collimation

Polymerization ShrinkagePolymerization Shrinkage

1.5-7 % volume



Open margins

± microleakage

± staining

± post-op sensitivity

Optical SafetyOptical Safety

Do not look dir ectly at light



y g

Protection r ecommended

± glasses

± shields

May impair ability

to match tooth shades

MaintenanceMaintenance

Periodic visual inspection of unitlight guide



± light guide

± filters

± bulb

Check irradiance

± radiometer

Strydom SADJ 2002

Contamination of Light TipContamination of Light Tip

R educes passage of light



R eflects light

± incr eases heat build-up

± shortens bulb lif e

R emove de bris

± polishing kit

± blade ± r e place light guide prn

Integrity of FiltersIntegrity of FiltersHalogenHalogen

Designed to select for blue



g

Can crack

± dropped or overheated

Coating prone to delamination

Ineff ective filter

± scatters rather than transmits light

Quality of Light SourceQuality of Light SourceHalogenHalogen

Blue intensity decr eases



± befor e brightness drops off

Fogging cuts output

± 30 - 40%

Bulb silvering

± discoloration of internal glass

± black oxides diminish light output

± mirror becomes less r eflective

Radiometer Radiometer

Consists of photosensitive diode

± specific for light



Measur es useful light output at curing tip

± hand-held

± built-in Light-specific radiometers

± halogen

± LED

Radiometer Radiometer

RecommendationsRecommendations

If irradiance drops



If irradiance drops

± inspect

light guide tip

filter (if applicable)

light source

battery de pletion (if applicable)

RegularlyRegularly--Used Curing Lights*Used Curing Lights*

Conventional Halogen 52%



LED 33%

High-intensity Halogen 31%

Plasma-Arc 12%

Other 1%

DPR 2005*Multiple r esponses

Advantages and limitationsAdvantages and limitations

Halogent bli h d t h l



± established technology

± r elatively inex pensive

± multiple curing modes ± poor efficiency

heat

fan

± limited bulb lif e


LED

± similar curing to halogen



± lightweight and quiet

± longer LED ³source´ lif e

± mor e efficient less lateral heat

± little or no fan necessary

± may not polymerize all photo-initiated materials

± batteries may have to be r e placed

Click her e for Synopsis of 2nd generation LED curing lights


Plasma Arc

± shorter curing times



shorter curing times

± mor e ex pensive

± higher heat potential

Argon Laser

± very ex pensive

± excellent collimation

± impractical for routine use



Sealers, Liners and BasesDefinition

Sealers liners and bases are intermediary



Sealers, liners and bases ar e intermediarymaterials that may be placed beneathdefinitive r estorative materials (e.g. amalgam,composite r esin, gold/porcelain inlays andonlays, etcetera) to protect the pulp.

F undamentals of O per at i ve Dent i st r y: A C ontempor ar y A pproach by Schwar tz , R . S . , Summi tt , J . B . and Robbi ns , J . W . ( 1997).

Sealers, Liners and Bases

applied to cavity pr e parations to

caries

toxins de pth of pr e paration



protect the pulp

from irritation or

in jury by:

cavity preparation

heat

de pth of pr e paration

restorative material

metallic r estoration (thermal

shock)

acid-containing cement

(chemical irritation)

seal between tooth and

r estorative material

Cavity Sealers/Dentin BondingAgents

Thin, protective coating over fr eshly



cut tooth structur e

± Dentin Bonding Agents

± Varnishes (ex. Copalite) - not used very

often anymor e!

Bonding Agents

Many products exist

Went from two-step to now



Went from two-step to now6th generation bondingsystems only requiring onestep

Primary function is to seal thedentinal tubules, thuspreventing post-operativesensitivity

Remember: No etchtechnique required whenusing a bonding agent underamalgam restoration

Varnish A natural gum (copal or rosin) in an organic

solvent (acetone, chloroform or ether)

The solvent evaporates leaving a protective film on the cut tooth



Seals the dentinal tubules

Provides a barrier to bacteria and oral fluids

Thin film usually no mor e than 2-5 µmEXAMPLES: Copalite ®, Copaliner ®

N ot used often clinically!!!

Resin Bonding Agents

Include dentin bondingsystems and all-purpose



y p p bonding systems

Serve the same functionsas sealers/varnishes buthave the additional benefitof bonding the r estorative material to tooth structur e,ther e by str engthening the tooth

EXAMPLES:Amalgambond®, All-Bond®

Resin Bonding AgentsResin Bonding Agents

Alloybond by SDI is the most common



Ease of use

Etch first, wash and dry,

applyP

RIMER first, thenlight cur e

BASE (one drop) +CATALYST (one drop)mixed together and

applied to dentin AMALGAM is condensed

immediately

Liners Provide a barrier to irritants lik e

varnishes BUT ALSO have a

THERAPEUTIC EFFECT such as ± Fluoride release (Glass Ionomer



Cements)

± Antibacterial effect (Glass IonomerCements, Calcium Hydroxide)

± Stimulation of the formation of reparative dentin (CalciumHydroxide)

± Adhesion to tooth structure (ResinBonding Agents)

Minimal thickness (less than 0.5mm)

Uses Of Calcium Hydroxide

Dentine

desensitizing agent Indirect pulp cap technique



Direct pulp cap technique

Endodontic intracanal dressing

Root canal sealar

Apexification

Apical plug

Microleakage demonstrater Hard tissue induction in root fractures , root

resorbtion, root perforation.

Calcium Hydroxide

accelerates formationof reparative (or



of r e parative (or tertiary dentin)

not bondable to tooth

aqueous solution

± DyCal

± ProCal

or r esin solution

± VLC Dycal

Calcium Hydroxide

INDICATIONS

± Placed in a thin layer near

CONTRA-

INDICATIONS



Placed in a thin layer near

the pulp in dee p

pr e parations

± IPC (Indir ect Pulp Cap)

OR

± Dir ect Pulp Cap

± Placed wher e dentin

thickness is less than 0.5-

1.0 mm

INDICATIONS

± Unnecessary in

shallow pr e parations

± Unnecessary wher e

dentin thickness is

gr eater than 1.0 mm

DyCal vs VLC DyCal

DyCal ± Soluble

VLC DyCal

L l bl



± Poor compr essive

str ength 1,200 lbs/sq.

in.

± Better Calcium r elease

and production of

tertiary dentin

Less soluble

Better compr essive

str ength 18,000 lbs/sq.in.

Less eff ective Calcium

r elease and production

of tertiary dentin

Bases Defined as a dentin r e placement material to

± allow less bulk of the definitive restorative material (ex.

amalgam) OR ± block out undercuts for inlay or onlay preparations



y y p p

± - W h y can t her e not be undercuts i n an i nlay pr e par at i on????

Must possess adequate str ength to support r estoration

Thickness maximum less than 2.0 mm

Types o f cements used for bases

± Glass Ionomer

± R einforced ZOE

± Zinc Phosphate

± Polycarboxylate

Glass Ionomer Cements

Close to ideal liner or base



Universal use EXCEPT for dir ect pulp

ex posur es or near ex posur es

Acce ptable compr essive str ength 12,500

lbs/sq. in.

R eleases fluoride

Adhesive bond to dentin

IDEAL PULP PROTECTIVEMATERIAL (R.E. Jordan))

biologically compatible,

non-irritating fast setting

b d ble t



g

stimulates dentin bridge

formation

rigid

minimum 10,000 p.s.i.

acid insoluble

chemical bond to dentin

bondable to

composite, amalgam

etc. fr ee flowing

anticariogenic

(Fluoride r elease)

radiopaque

Reinforced ZOE

IR M (Intermediary

R estorative Material)



)

Non-irritating to the pulp

Low compr essive str ength

8,000 lbs/sq. in.

Does not bond to tooth

structur e

Stimulates r e parative

dentin formation

Zinc Phosphate Cement zinc oxide powder

aqueous sol¶n of phosphoric acid acidic pH

i i i h l



irritating to the pulp

r equir es a varnish to seal the dentinaltubules

compr essive str ength is 15,000lbs/sq. in.

does not bond to tooth structur e

TE NACIN

HY-BOND



Polycarboxylate Cement

zinc oxide powder

polyacrylic acid



polyacrylic acid

non-irritating to the pulp

compr essive str ength of

8,000 lbs/sq. in.

chemically bonds to tooth

structur e

POLY F

DUR ELON

Minimum Basing Concept

Since little or no pulp reaction occurs

when there is 2 0 mm thickness of dentin



when there is 2.0 mm thickness of dentin

over the pulp, a base is not necessary at

all unless there is less than 2.0 mm of dentin thickness over the pulp



Dental bleachingDental bleaching

internal non vital bleachinginternal non vital bleaching



Internal bleachingHistory

19 th century ( Oxalic acid )

Many agents wer e used later including :



Chloride and Pyrozone(25% H2O2 +5%

Ether.)

1884 Harlan first r ecor ded (I. B) H2O2

1927 Prinz H2O2 + sodium perborate

1937 Ames used 5 :1 H2O2 100 % +1 part ether.

Late 1950 Superoxol or Pyrozone With heat

Internal bleachingHistory Con..

1961 Spasser sodium perborate walking bleach.

d l di



1963 Nutting and Poe Superoxol+Sodium

Perborate Walking Bleach Technique.

1980 Howell add phosphoric acid to r emove

the smear layer prior to bleaching agent. early 1990s sodium perborate + water was found to be

saf er , eff ective and simple technique .(Rotstein 1993)

Causes of discolorationof non vital teethof non vital teeth

Discoloration could be attributed to ::

- Pulpal degeneration .



- Hemorrhage in the pulp chamber

following trauma. (iron sulfides which ar e

nonsoluble compounds)

- Failure to remove the pulp chamber

- Due to r estorative materials e g. Amalgam

- Finally some endodontic materials

(e.g. silver cones )

Oxidizing agents used:

- Hydrogen peroxide.30% (e.g. Superoxol)

- Sodium perborate .

- Sodium hypochlorite 5 6%



- Sodium hypochlorite 5.6%.

- Other oxidizing agents e.g. glycerin-ur ea

peroxide (Amosan).The most commonly used agents ar e the combination of hydrogen Peroxide and sodium perborate .

(Sodium perborate) Walkingbleach

As a powder is mor e stable

Promising results



Decreased tr eatment time

The decr eased amount of gas producedwhen mixed with H2O2 decr eased the destruction of the temporary sealing.

Not associated with external cervicalresorption

Theories of bleaching

The discolor ed dental substance ish d b ith



changed by either :

1- Electrons from oxygen atomsr esulted from hydrogen peroxide.

2- or by combining with the

r eleased oxygen atoms

When to bleach

- Walking bleach can be done at the same visit with the root canal filling



(impr essive r esults for patients as they

ar e fast following root canal tr eatment) - Any time even years after root canal

tr eatment.

- Many years after discoloration .

Contraindicationsof internal bleachingof internal bleaching

- Hypoplastic teeth - Cracked teeth



- Teeth with sever ely undermined enamel.

- In teeth that ar e heavily restored withsilicate , acrylic or composite r estorations.

- If the discoloration is caused by metallic

salts (e.g. silver amalgam)

- Poorly filled canals .

Complications of internalbleaching.

1-External cervical r esorption.2 Spillage of bleaching agent



2-Spillage of bleaching agent.

3-Failur e to bleach.4-Over -bleaching.

5-Brittleness of the tooth crown.

6-R e-discoloration.

External cervical resorption.first reported by Harrington Notkin 1979

- Diffusion of bleaching agent through

dentinal tubules to the periodontal membrane. - Use of heat



- Trauma

- No lining over the r emaining Gutta Percha filling.

- Bacterial leakage following bleaching

- Trauma of the cementum

- Alteration of the pH surrounding bone.

Prognosis of non vitalbleaching

Bleaching is an eff ective, easyd i i th d



and inex pensive method.

With a success rate of 50%over period of 3-5 years, as the other 50% failed either to bleach(25%) or r e-discolor ed (25%).

Re-discoloration ?

Chemical reduction of the oxidation products formed as r esults of bleaching

i h H2O2



with H2O2

Marginal leakage ( bacteria , chemical )

Further trauma

Saliva and tissue fluids ( as a r esult of

incr eased permeability )

Factors that may influence theprognosisAge of the patient

Etiology of discoloration .

R t f di l ti



Rate of discoloration.

Duration of discoloration.Degr ee of discoloration.

Tr eatment time.Heat temperatur e .

Conclusion.

The methods of internal bleachingr eviewed above, provide us with



useful information's about these

simple, inexpensive and effectivealternatives of crowns that could

change our smile



Dental bleachingDental bleaching



vital bleachingvital bleaching

Estheticsin dentistry through history

by definition: is the science of beautyThat particular detail of animate or inanimate

object that makes it appealing to the eye.



j pp g y

Criteria of beauty have been influenced by1- Environment

2- Cultur e -

-Ancient Asian ( black teeth , precious stones)-Primitive Africans (red, orange, black decorative)

-Modern civilized cosmetically conscious world.

Estheticin modern civilization considered

Well contoured, well aligned, white teethset the standard of beauty , And not only



y , y

considered attractive but also indicates:

a- Nutritional healthb- Hygienic pride

c- Economic status

d-Self - esteem.e- Sexuality

Who is responsible ?for this white teeth -mania

- advancement in technology,materials and techniques



materials and techniques

- may be the psychological str ess is

substantiated by the existence of

multibillion dollar dentifrice mark et

.

- Media and telecommunications

Vital bleaching

In-office ( at surgery ) bleaching



Nightguar d vital bleaching

Over-the-counter pr e paration

In-office ( at surgery ) bleachingDisadvantagesDisadvantages (H(H22oo2 302 30%)%)

Complete r e peated isolation withrubber dam is a problem ( anterior



teeth only )

Patient discomfort and sensitivity

Caustic agent

Unpr edictable r esults

Fees ?

Nightguard vital bleaching((Dentist prescribedDentist prescribed-- home appliedhome applied ))

First introduced 1989( Haywood V.B, Heymann H.O )

C fi d h i fill d i h



Custom- fitted prosthesis filled with

10 % carbamide peroxide Worn for a f ew hours each day ??

Less ex pensive Less complicated

Carbamide peroxide 10 %

Composed of approximatelyH2O2 3 % & 7 % Urea



H2O2 3 % & 7 % Ur ea

H2O2 degrades into Water and Oxygen

Ur ea degrades into Ammonia and Carbon dioxide

Factors affectingdecomposition of H2O2

-Temperatur e

- Impurity



- pH of the solution ( stable in acidic

solution , while stronger in alkaline solution)

-Metal ions

Adverse effects of vitalbleaching

-Sensitivity

Teeth , Gingival tissues ( ill fitting posthesis)

D d Ti f i P th ti



De pend {Time of wearing , Prosthetic

type (professional or commercial ),Concentration of bleaching agent.}

Eff ects that ar e transient in natur e.

-Restorative fillings exists.- lower bonding values to dental tissues.

Safety of vital bleachingproducts?

Since tooth whiteners may be

ll d d i h bl hi



swallowed during the bleaching

procedur e , ( as some these materials ar e worn for many hours daily for 2-6 weeks

or even mor e ).

A concern of their toxicity must exist

Choice of bleaching systemFactors ?

Financial cost - ( Dentist, Patient)

Tolerance of candidates ( tr eatment time,

prosthesis accept )



prosthesis acce pt.)

Acce ptance ( Taste , Prosthesisdesign)

Concentration ( sensitivity ? )

Fr equency of changing the solution.

Over the counter bleachingsystems

1-Early used materials (thr ee ste ps procedur e)

a- An acidic pr e- rinse

b- A pplication of lower str ength peroxide



g

material without a prosthesis

c- A final application of titanium dioxide tooth paste

2-Later developed materials

a- Peroxide material similar str ength tothose used by dentists

b- Use of Prosthesis boil and form t e

Why should bleaching bcarried out by the dentist?

Corr ect diagnosis of discoloration

( vitality radiographs photographs )



( vitality, , radiographs , photographs )

Tr eatment planningContraindications ?, a need of RCT ?)

Fabrication of the prosthesis

Insertion of prosthesis

A will-fitting prosthesisAdvantages Vs OTC products

Thinner softer materials ( T.M.D problems )Will not place orthodontic forces .



Or produce trauma or slippage of the material

Mor e comfortable if tr eatment time extended? Bleaching material appropriately localized

specially if not all the teeth ar e not involved.

Thick er bleaching materials r equir edr eservoirs.

ADA statement on Safety of H2O2containing products (1997)

Short term use of H2O2 consider ed safe and

eff ective ( 2-7 days )However ex pr essed concern of long term use



of these products.

Noted that some products ar e acidic in natur e and may damage enamel, dentine and certainr estorative materials.

To date, no significant adverse health hazar dshave been associated with these products.

Hydrogen peroxide toothHydrogen peroxide tooth--whitening (bleaching)whitening (bleaching)products: Review of adverse effects and safetyproducts: Review of adverse effects and safety

issuesissuesC. J.C. J. Tr edwinTr edwin, S., S. Naik Naik, N. J. Lewis and C. Scully CBE, N. J. Lewis and C. Scully CBE

CONCLUSIONS



CONCLUSIONS

1. Cervical root r esorption is a possible consequence of

internal bleaching and is mor e fr equently observed in

teeth tr eated with a thermo-catalytic procedur e.

BRITISH DENTAL JOURNAL VOLUME 200 NO. 7 APR 8 2006



CONCLUSIONS



CONCLUSIONS

2. Tooth sensitivity is a common side eff ect of external

tooth bleaching.

3. Tooth-bleaching agents should not be used [for at least

24 hours] prior to r estorative tr eatment with r esin-based materials.




4. Urgent clinical studies ar e r equir ed on the genotoxic and tumour-promoting eff ects



g q g p g

of hydrogen peroxide bleaching agents. Until such studies ar e available it is

r ecommended that tooth-bleaching products using concentrated H2O2 should not

be used without gingival protection to pr event ex posur e of the gingival tissues or mucosae.

The use of H2O2 containing products should be avoided in patients with damaged or

diseased tissues. For nightguar d vital bleaching, minimal amounts of low dose

H2O2 (10% carbamide peroxide) is pr ef err ed, avoiding prolonged and longtermuse. Patients undergoing nightguar d vital beaching should be r egularly r eviewed and

monitor ed.BRITISH DENTAL JOURNAL VOLUME 200 NO. 7 APR 8 2006

However, clinical studies addr essing other adverse eff ectsar e lacking.

Direct contact with hydrogen peroxide induces genotoxic

Hydrogen peroxide toothHydrogen peroxide tooth--whitening (bleaching) products:whitening (bleaching) products:Review of adverse effects and safety issuesReview of adverse effects and safety issues

C. J.C. J. TredwinTredwin, S., S. NaikNaik, N. J. Lewis and C. Scully CBE, N. J. Lewis and C. Scully CBE



Dir ect contact with hydrogen peroxide induces genotoxic

eff ects in bacteria and cultur ed e pithelial cells, but the eff ect

is r educed or totally abolished in the pr esence of metabolizing enzymes.

Several carcinogenesis studies, including the hamster cheek

pouch model, indicate that hydrogen peroxide (H2O2)

might possibly act as a promoter.


Abstract Abstract Hydrogen peroxide in the form of carbamide peroxide is widely used for tooth whitening

(bleaching), both in prof essionally- and in self-administer ed products. Adverse eff ects

have become evident. Cervical root r esorption is a possible consequence of internal

bleaching and is mor e fr equently observed in teeth tr eated with the thermo-catalytic

procedur e.

Tooth sensitivity is ex perienced in 15-78% of patients undergoing external tooth

bl hi H li i l t di dd i th d ff t l ki Di t



bleaching. However, clinical studies addr essing other adverse eff ects ar e lacking. Dir ect

contact with hydrogen peroxide induces genotoxic eff ects in bacteria and cultur ed

e pithelial cells, but the eff ect is r educed or totally abolished in the pr esence of

metabolising enzymes.

Several carcinogenesis studies, including the hamster cheek pouch model, indicate that

hydrogen peroxide (H2O2) might possibly act as a promoter. Until further clinical

r esearch is concluded to addr ess the question of possible carcinogenicity, it is

r ecommended that: tooth-bleaching products using concentrated H2O2 should not be used

without gingival protection; that H2O2 containing products should be avoided in patients with damaged or diseased

soft tissues. For nightguar d vital bleaching, minimal amounts of low dose H2O2

(including in the form of carbamide peroxide) ar e pr ef err ed, ther e by avoiding prolonged

and concentrated ex posur es.

1why to restore teeth2011-5

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