Direct Posterior Resin Composites (I) · Conservation of tooth structureConservation of tooth structure TheadhesivepreparationThe adhesive preparation Narrower outline form this prep

Direct Posterior Resin Composites (I)Direct Posterior Resin Composites (I)Direct Posterior Resin Composites (I)Direct Posterior Resin Composites (I)

Motaz A Ghulman BDS MSD CAGS DScDMotaz A Ghulman BDS MSD CAGS DScDMotaz A Ghulman BDS MSD CAGS DScDMotaz A Ghulman BDS MSD CAGS DScDMotaz A. Ghulman, BDS, MSD, CAGS, DScDMotaz A. Ghulman, BDS, MSD, CAGS, DScDAssistant Professor of Operative/Esthetic DentistryAssistant Professor of Operative/Esthetic Dentistry

Chairman, Conservative Dental Sciences DepartmentChairman, Conservative Dental Sciences Department

Motaz A. Ghulman, BDS, MSD, CAGS, DScDMotaz A. Ghulman, BDS, MSD, CAGS, DScDAssistant Professor of Operative/Esthetic DentistryAssistant Professor of Operative/Esthetic Dentistry

Chairman, Conservative Dental Sciences DepartmentChairman, Conservative Dental Sciences DepartmentFaculty of DentistryFaculty of Dentistry

King Abdulaziz UniversityKing Abdulaziz UniversityFaculty of DentistryFaculty of Dentistry

King Abdulaziz UniversityKing Abdulaziz University

IntroductionIntroductionIntroductionIntroduction

ThTh f i it t tif i it t tiThe The useuse of resin composites as a restorative of resin composites as a restorative materialmaterial

has recently increased greatlyhas recently increased greatly

M t h thM t h th l f t l t thl f t l t thMatches the Matches the color of natural teethcolor of natural teethContains Contains no mercuryno mercury

Th ll dTh ll dThermally nonconductiveThermally nonconductiveBonds to tooth structureBonds to tooth structure with the use of adhesiveswith the use of adhesives

The The problemsproblems associated with the use of resin associated with the use of resin composites as a restorative materialcomposites as a restorative material

ShrinkageShrinkage that occurs on settingthat occurs on settingShrinkageShrinkage that occurs on settingthat occurs on settingOccasional Occasional postoperative sensitivitypostoperative sensitivityLL hh id lid l iiLessLess--thanthan--ideal ideal resistance to wearresistance to wear

Minimizing the negative aspectsMinimizing the negative aspects of resin of resin M g the egat ve aspectsM g the egat ve aspects of resin of resin composites as a restorative materialcomposites as a restorative material

requires meticulous requires meticulous techniquetechnique

TechniqueTechniqueqqis is the most important variablethe most important variable governing the success of governing the success of

posterior resin composites restorationsposterior resin composites restorationsposterior resin composites restorationsposterior resin composites restorations

LongevityLongevity Longivity of Longivity of amalgamamalgam restorations restorations LongevityLongevity InvistigatorsInvistigators Study time (y)Study time (y) No. of restorationsNo. of restorations AFR (%)AFR (%)

Smales et al, Smales et al, 19911991 1818 11,,801801 22..55

Smales et al, Smales et al, 19911991 1818 11,,680680 11..55--66..00

Properly accomplished Properly accomplished posterior resin compositesposterior resin composites

Osborne et al, Osborne et al, 19911991 1414 320320 00..99

Crabb, Crabb, 19811981 1010 407407 66..33

Collins et al, Collins et al, 19881988 88 5252 00..77

QuiteQuite durabledurable

can becan be Longivity of Longivity of castcast--goldgold restorations restorations

InvistigatorsInvistigators Study time (y)Study time (y) No. of restorationsNo. of restorations AFR (%)AFR (%)

Fritz et al, Fritz et al, 19921992 11--3030 22,,717717 33..00--44..00Quite Quite durabledurable& & comparable to other materialscomparable to other materials,,

id ri th t thid ri th t th

Bently & Drake, Bently & Drake, 19861986 11--2525 11,,207207 00..99

Crabb, Crabb, 19811981 1010 8686 55..99

Longivity of Longivity of posterior resin compositeposterior resin composite restorations restorations considering that the considering that the composites used in long term composites used in long term studies arestudies are

InvistigatorsInvistigators Study time (y)Study time (y) No. of restorationsNo. of restorations AFR (%)AFR (%)

Wilder et al, Wilder et al, 19961996 1717 6060 11..33

Barnes et al, Barnes et al, 19911991 88 2828 22..99studies arestudies areof earlier formulationsof earlier formulationsthat materials have improved that materials have improved

Collins et al, Collins et al, 19981998 88 161161 11..22--22..00

Wilson et al, Wilson et al, 19911991 55 9494 33..44

Fukushima et al, Fukushima et al, 19921992 55 432432 11..00

considerably in recent yearsconsiderably in recent years Geurtsen et al, Geurtsen et al, 19941994 44 11,,214214 33..00

K h lK h lKey to the long term successKey to the long term success

Cavity sizeCavity sizeR iR iRestoration typeRestoration type

Tooth typeTooth typeTooth typeTooth type

Properly used resin compositeProperly used resin compositeProperly used resin compositeProperly used resin compositehas demonstrated the ability to perform as well as has demonstrated the ability to perform as well as

amalgam in posterior restorations for up to amalgam in posterior restorations for up to 1010 years years (Fukushima, (Fukushima, 19921992; Mair, ; Mair, 19981998; Rowe, ; Rowe, 19891989))

AdvantagesAdvantagesAdvantagesAdvantages

Advantages of resin composites as aAdvantages of resin composites as aAdvantages of resin composites as a Advantages of resin composites as a posterior restorative materialposterior restorative material

EstheticsEstheticsConservation of tooth structureConservation of tooth structure

Adh i hAdh i hAdhesion to tooth structureAdhesion to tooth structureLow thermal conductivityLow thermal conductivityyy

Elimination of galvanic currentsElimination of galvanic currentsdi idi iRadiopacityRadiopacity

Alternative to amalgamAlternative to amalgamgg



Adhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structureLow thermal conductivityLow thermal conductivity

Elimination of galvanic currentsElimination of galvanic currentsR di itR di itRadiopacityRadiopacity


EstheticsEstheticsEstheticsEsthetics

ManufacturersManufacturersManufacturersManufacturershave developed have developed sophisticated sophisticated

resin composite systemsresin composite systemsresin composite systemsresin composite systems

with multiplewith multiple

ShadesShades

pp

Shades Shades TentsTents

& Opaque resins& Opaque resins& Opaque resins& Opaque resins

that allow the practitioner to place highly esthetic restorations

EstheticsEstheticsEstheticsEstheticsClinical studiesClinical studiesClinical studiesClinical studies

often report often report excellent color matchexcellent color match of resin composite with tooth of resin composite with tooth structurestructurestructurestructure

Vi ibl li hVi ibl li h d id iVisible lightVisible light--cured compositescured composites

LessLess amine contentamine content than the autocured compositesthan the autocured composites

havehave

LessLess amine contentamine content than the autocured compositesthan the autocured composites

Less yellowing of the restorations & greater color stability over time

resulting in& greater color stability over time

EstheticsEstheticsEstheticsEstheticsHybridHybrid

MicrofilledMicrofilled

HybridHybridmore more heavily filledheavily filled, so, so

have the have the smoothest surface finishsmoothest surface finish than than all other systemsall other systems

they tends tothey tends to

impart a more impart a more opaque appearanceopaque appearance to to restorationsrestorationstends totends to

Stain less than other systems

restorationsrestorations

Stain less than other systems






Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure

R h dR h dResearches todayResearches todayrecommend a more conservative approachrecommend a more conservative approach

The adhesive preparationThe adhesive preparation(limits the removal of tooth structure to that needed to (limits the removal of tooth structure to that needed to

eliminate eliminate carious lesion & fragile enamelcarious lesion & fragile enamel))have been evolved have been evolved

to take advantage of composites positive propertiesto take advantage of composites positive properties& to minimize its negative ones& to minimize its negative onesgg


The adhesive preparationThe adhesive preparationThe adhesive preparationThe adhesive preparationfor post class II for post class II differsdiffers from traditional amalgam design of from traditional amalgam design of

G V BlackG V BlackG.V. BlackG.V. Black

in several waysin several ways

ShallowerShallower outline formoutline formNarrowerNarrower outline formoutline form

RoundedRounded internal line anglesinternal line anglesRoundedRounded internal line anglesinternal line anglesNo extensionNo extension for preventionfor prevention


Th dh i iTh dh i iThe adhesive preparationThe adhesive preparation

ShallowerShallower outline formoutline form

ti t d t bti t d t b h llh llpreparation tend to be preparation tend to be shallowershallowerno need to penetrate dentinno need to penetrate dentin if the if the carious lesion does notcarious lesion does notcarious lesion does notcarious lesion does not

this

Conserves tooth structureConserves tooth structureExpands the area of enamelExpands the area of enamel available available for bondingfor bonding


The adhesive preparationThe adhesive preparationThe adhesive preparationThe adhesive preparation

NarrowerNarrower outline formoutline formthis prep tends to have thatthis prep tends to have thatthis prep tends to have that,this prep tends to have that,

which allows

less occlusal contactless occlusal contact on the on the restorationrestoration& & reduce wearreduce wear

A less bulky restorationA less bulky restoration, , helps to helps to d r th d r ff t f r id r th d r ff t f r idecrease the adverse effect of resin decrease the adverse effect of resin polymerization shrinkagepolymerization shrinkage

resulting in improved marginal integrity & less cuspal deflection


The adhesive preparationThe adhesive preparation

RoundedRounded internal line anglesinternal line anglesRoundedRounded internal line anglesinternal line angles

this

conserves tooth structureconserves tooth structured t t tid t t tidecreases stress concentrationdecreases stress concentrationassociated with sharp line anglesassociated with sharp line angles&& enhances resin adaptationenhances resin adaptation duringduring& & enhances resin adaptationenhances resin adaptation during during placementplacement


Th dh i iTh dh i iThe adhesive preparationThe adhesive preparationNo extensionNo extension for preventionfor prevention

N t i f p tiN t i f p tiNo extension for preventionNo extension for preventionThe The occlusal fissuresocclusal fissures are included in are included in the prepthe prepthe prepthe prep

h f d di hih f d di hi

only ifonly if

the presence of decay dictates this the presence of decay dictates this need need

Extending the class II prep Extending the class II prep g p pg p pthrough the occlusal groovesthrough the occlusal grooves::

Does not make the restoration more resistant to fracture than the moreDoes not make the restoration more resistant to fracture than the more conservative proximal slot restoration


In In clinical studiesclinical studies::Use of aUse of a proximal slot prepproximal slot prep

Adjacent pits & fissuresAdjacent pits & fissures, , can be treated with sealantscan be treated with sealantsUse of a Use of a proximal slot prepproximal slot prep

for post compositesfor post composites to enhance caries preventionto enhance caries prevention

No failure after No failure after 22 years in years in

showedshowed

yyservice (Kreulen et al, service (Kreulen et al, 19951995))7070% f% f 10107070% success after up to % success after up to 1010years (Nordbo et al, years (Nordbo et al, 19981998))


Examples ofExamples ofp fp foutline form of posterior resin outline form of posterior resin

composite restorationscomposite restorationscomposite restorationscomposite restorationsEach is designed to Each is designed to treat the carious lesiontreat the carious lesiontreat the carious lesion treat the carious lesion presentedpresentedNoneNone has thehas theNone None has thehas the““standard”standard” shapeshape



Adhesion to tooth structureAdhesion to tooth structureLow thermal conductivityLow thermal conductivityLow thermal conductivityLow thermal conductivity

Elimination of galvanic currentsElimination of galvanic currentsRadiopacityRadiopacity

Alternative to amalgamAlternative to amalgamAlternative to amalgamAlternative to amalgam

Adhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structure

The bond between resin composite & tooth structureThe bond between resin composite & tooth structure(achieved with the bonding system)(achieved with the bonding system)

offers the potential tooffers the potential to

seal the marginsseal the margins of the restorationof the restorationi f i i hi f i i h i fi freinforce remaining tooth structurereinforce remaining tooth structure against fractureagainst fracture






Low thermal conductivityLow thermal conductivityLow thermal conductivityLow thermal conductivity

There is anThere is anThere is an There is an isolating effect for resin compositesisolating effect for resin compositesg ff f pg ff f p

becausebecause

resin composites resin composites do not transmit temperature changesdo not transmit temperature changesdo not transmit temperature changesdo not transmit temperature changes

that that helps tohelps to

reduce postoperative temperature sensitivityreduce postoperative temperature sensitivity






Elimination of galvanic currentsElimination of galvanic currentsElimination of galvanic currentsElimination of galvanic currents

Resin composites Resin composites d t t i t ld t t i t ldo not contain metaldo not contain metal

ddand soand so

will not initiate or conduct will not initiate or conduct galvanic currentsgalvanic currentsgalvanic currentsgalvanic currents



Adhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structureAdhesion to tooth structureLow thermal conductivityLow thermal conductivity

Elimination of galvanic currentsElimination of galvanic currentsRadiopacityRadiopacityp yp y

Alternative to amalgamAlternative to amalgam

RadiopacityRadiopacityRadiopacityRadiopacity

Why do we needWhy do we needWhy do we need Why do we need radiopaque restorative materials ?radiopaque restorative materials ?

to allow the practitioner to to allow the practitioner to evaluate the contour & evaluate the contour & marginal adaptationmarginal adaptation of the restorationsof the restorationsg pg p

& to & to distinguish among the restorations, carious lesions & distinguish among the restorations, carious lesions & sound tooth structuresound tooth structuresound tooth structuresound tooth structure

Most modern resin composites have a radiopacity, in excess to that of enamel & Most modern resin composites have a radiopacity, in excess to that of enamel & greater than that of an equal thickness of aluminumgreater than that of an equal thickness of aluminumg f q fg f q f






Alternative to amalgamAlternative to amalgamAlternative to amalgamAlternative to amalgam

AmalgamAmalgam despite having a long track record of clinical successdespite having a long track record of clinical successAmalgamAmalgam, , despite having a long track record of clinical successdespite having a long track record of clinical successhas has declined in usedeclined in use as a as a restorative materialrestorative material due todue to the following:the following:

Its Its unaesthetic appearanceunaesthetic appearanceIts Its mercury contentmercury content

Amalgam is less attractive to the professionals as government Amalgam is less attractive to the professionals as government agencies consider classifying it as agencies consider classifying it as hazardous wastehazardous waste

And requiring that dental offices installAnd requiring that dental offices install expensive system to expensive system to f t tf t tremove mercury from waste waterremove mercury from waste water

For these reasons, For these reasons, resin composites use in posterior restorationsresin composites use in posterior restorations continues to gain continues to gain ,, p pp p ggpopularity in the professionpopularity in the profession

DisadvantagesDisadvantagesDisadvantagesDisadvantages

Disadvantages of resin composites as aDisadvantages of resin composites as aDisadvantages of resin composites as a Disadvantages of resin composites as a posterior restorative materialposterior restorative material

Polymerization shrinkagePolymerization shrinkageSecondary cariesSecondary caries

Postoperative sensitivityPostoperative sensitivityPostoperative sensitivityPostoperative sensitivityDecreased wear resistance & other mechanical propertiesDecreased wear resistance & other mechanical properties

V i bl d f iV i bl d f iVariable degree of conversionVariable degree of conversionInconsistent dentin bonding (marginal leakage)Inconsistent dentin bonding (marginal leakage)

Technique sensitivityTechnique sensitivity



Postoperative sensitivityPostoperative sensitivityp yp yDecreased wear resistance & other mechanical propertiesDecreased wear resistance & other mechanical properties

Variable degree of conversionVariable degree of conversionVariable degree of conversionVariable degree of conversionInconsistent dentin bonding (marginal leakage)Inconsistent dentin bonding (marginal leakage)


Polymerization shrinkagePolymerization shrinkagePolymerization shrinkagePolymerization shrinkage

M f blM f bl Contraction forces on cuspsContraction forces on cuspsMost of problems Most of problems associated with associated with posterior resinposterior resin

Contraction forces on cuspsContraction forces on cuspsCan result inposterior resin posterior resin

compositescomposites Cuspal deformationCuspal deformationC b l t d

Directly or indirectly to Directly or indirectly to polymerization shrinkagepolymerization shrinkage

Enamel cracks & crazes Enamel cracks & crazes (& ultimately (& ultimately decreased fracture resistance of the cuspsdecreased fracture resistance of the cusps))

Can be related

polymerization shrinkage,polymerization shrinkage,may pull away from the may pull away from the

least retentive cavityleast retentive cavityleast retentive cavity least retentive cavity margins (little or no enamel margins (little or no enamel on them), resulting in gap on them), resulting in gap

f tif tiformationformation

Polymerization shrinkagePolymerization shrinkagePolymerization shrinkagePolymerization shrinkageRecent researchesRecent researches The most commonly used The most commonly used Recent researchesRecent researches techniques suggested to decrease techniques suggested to decrease

the adverse effect of the adverse effect of polymerization techniquepolymerization technique

Provides evidence that

polymerization shrinkage polymerization shrinkage occurs toward walls of cavity occurs toward walls of cavity

p y qp y qIncremental placement of VLC Incremental placement of VLC

compositecompositepreparation to which it is preparation to which it is

bonded, bonded, regardless of the initiator moderegardless of the initiator mode

ppwhich

regardless of the initiator mode regardless of the initiator mode (Versluis et al., (Versluis et al., 19981998)) Decreases the effect of setting contraction Decreases the effect of setting contraction (by (by

reducing the bulk of resin composite reducing the bulk of resin composite cured at a time)cured at a time)cu ed at a t e)cu ed at a t e)

Reduces the ratio of bonded to unbonded surface Reduces the ratio of bonded to unbonded surface areaarea (which helps to relieve the stress (which helps to relieve the stress

developed at the bond between tooth & developed at the bond between tooth & resin composite)resin composite)

Incremental placement techniqueIncremental placement techniqueIncremental placement techniqueIncremental placement technique


Polymerization shrinkagePolymerization shrinkagePolymerization shrinkagePolymerization shrinkageSecondary cariesSecondary caries

P i i i iP i i i iPostoperative sensitivityPostoperative sensitivityDecreased wear resistance & other mechanical propertiesDecreased wear resistance & other mechanical properties

Variable degree of conversionVariable degree of conversionInconsistent dentin bonding (marginal leakage)Inconsistent dentin bonding (marginal leakage)co siste t de ti bo di g ( a gi a ea age)co siste t de ti bo di g ( a gi a ea age)


Secondary cariesSecondary cariesSecondary cariesSecondary caries

S d iS d iSecondary cariesSecondary cariesIs

a significant cause of failure of significant cause of failure of posterior resin composite posterior resin composite

Th f h i h dTh f h i h dp pp p

restorationsrestorations(the (the marginal gapmarginal gap found at the found at the i i l i l fi i l i l f

These facts emphasize the needThese facts emphasize the need

forgingival margin as a result of gingival margin as a result of polymerization shrinkage)polymerization shrinkage) Regular recallRegular recall

&& l f lll f ll f i i hf i i h

for

the the ingress of the cariogenic bacteriaingress of the cariogenic bacteria

& & close followclose follow--upup of patients with of patients with posterior resin composite posterior resin composite

restorationsrestorations

allows

g f gg f g






Postoperative sensitivityPostoperative sensitivityPostoperative sensitivityPostoperative sensitivity

Postoperative sensitivity, Postoperative sensitivity, h b i d i hh b i d i hhas been associated withhas been associated with

the placement of posterior resin composite restorationsthe placement of posterior resin composite restorationsdiminished somewhat with diminished somewhat with improvement in dentine adhesiveimprovement in dentine adhesive

CarefulCareful adherence to the guidelinesadherence to the guidelines for restoration placementfor restoration placementCareful Careful adherence to the guidelinesadherence to the guidelines for restoration placement for restoration placement will help to reduce this problemwill help to reduce this problem

Postoperative sensitivityPostoperative sensitivityPostoperative sensitivityPostoperative sensitivity

R f h f i i i iR f h f i i i iReasons for the occurrence of postoperative sensitivityReasons for the occurrence of postoperative sensitivityPolymerization shrinkagePolymerization shrinkage ((the most commonly accepted theory)the most commonly accepted theory)

results inresults in

1.1. Gap formationGap formation ((allows a slow, continuous outflow of dentinal fluid from allows a slow, continuous outflow of dentinal fluid from the pulp to the gap)the pulp to the gap)p p g p)p p g p)

2.2. Contraction forcesContraction forces ((may also results in cuspal deformation with resultant may also results in cuspal deformation with resultant cracking & crazing of the remaining tooth structure) cracking & crazing of the remaining tooth structure) g g g )g g g )

3.3. Flexure of resin composite under an occlusal loadFlexure of resin composite under an occlusal load ((may cause hydraulic may cause hydraulic pressure in the tubular fluid to be transmitted to the odontoplastic processpressure in the tubular fluid to be transmitted to the odontoplastic processp b d b d d p pp b d b d d p p



Postoperative sensitivityPostoperative sensitivityp yp yDecreased wear resistance, other mechanical propertiesDecreased wear resistance, other mechanical properties



Decreased wear resistance, other Decreased wear resistance, other mechanical properties, & water sorptionmechanical properties, & water sorption

R i iR i iResin composite wearResin composite wear Generally, wear can be Generally, wear can be related to either material related to either material

or clinical factorsor clinical factorsresults fromresults from

the combination of the combination of chemical damage to chemical damage to the surface of the materialthe surface of the material & & mechanical mechanical

breakdownbreakdown

or clinical factorsor clinical factorsMaterial factors,Material factors, relates primarily to relates primarily to

the resin composite’sthe resin composite’s fillerfillerbreakdownbreakdown the resin composite s the resin composite s filler filler contentscontents, ,

particle sizeparticle size, , & & distributiondistribution) )

Clinically relevant wear factors,Clinically relevant wear factors,includeincludeinclude include

the the size size of the restoration, of the restoration, its its location location in the arch, & in the arch, &

the the occlusal loadocclusal load it must withstand)it must withstand)

Decreased wear resistance, other Decreased wear resistance, other mechanical properties, & water sorptionmechanical properties, & water sorption

Other mechanical Other mechanical propertiesproperties

Failure of resin composite restorations Failure of resin composite restorations associated with its high elastic associated with its high elastic

deformation (ie, low deformation (ie, low modulus of elasticity) ) propertiesproperties ( ,( , f y))have included, have included, bulk fracture,

microcrack formation, & relatively low resistance to occlusal loading

Generally, the more closely the mechanical

ti f

g

Resin composite materials have low f t t h l ti t t lliproperties of a

restorative material simulate those of

fracture toughness relative to metallic restorative materials

enamel & dentin, the better the restoration’s

l it

As the mismatch in thermal expantionbetween the composite material & the

tooth structure increases so doeslongevity tooth structure increases, so does marginal leakage






Variable degree of cureVariable degree of cureVariable degree of cureVariable degree of cure

As the degree of cure increases the mechanicalAs the degree of cure increases the mechanicalAs the degree of cure increases, the mechanical As the degree of cure increases, the mechanical properties improveproperties improve

A decreased degree of cureA decreased degree of cure causescausessignificantlysignificantly increased wearincreased wearsignificantly significantly increased wearincreased wear

Visible light cured compositesVisible light cured composites have been shown to achieve a have been shown to achieve a hh hi h d fhi h d f h d i lh d i lsomewhat somewhat higher degree of curehigher degree of cure than autocured materialsthan autocured materials

Variable degree of cureVariable degree of cureVariable degree of cureVariable degree of cure

Several factors influence the extent of Several factors influence the extent of Several factors influence the extent of Several factors influence the extent of polymerization of VLC compositespolymerization of VLC composites

Light r sh d sLight r sh d s c re more easil & in less time than darkerc re more easil & in less time than darkerLighter shadesLighter shades cure more easily & in less time than darker cure more easily & in less time than darker shadesshades

Resins composites withResins composites with larger filler particleslarger filler particles tend to transmittend to transmitResins composites with Resins composites with larger filler particleslarger filler particles tend to transmit tend to transmit light through the material more effectively than those with light through the material more effectively than those with

smaller filler particles smaller filler particles The longer the The longer the duration of the curingduration of the curing with the light, the more with the light, the more

effective is the cureeffective is the cureThTh hi k f h ihi k f h i h ld b li i dh ld b li i d 22 00The The thickness of each incrementthickness of each increment should be limited to should be limited to 22..00mmmm

DC is inversely related to the DC is inversely related to the distance of the light tipdistance of the light tip from the from the resin compositeresin compositeresin composite resin composite






Inconsistent dentin bonding (marginal Inconsistent dentin bonding (marginal leakage)leakage)

P l i ti h i kP l i ti h i kPolymerization shrinkagePolymerization shrinkagecauses

The composite to pull a way from cavity margin

(resulting in (resulting in gap formationgap formation)) This sometimeThis sometime

results inD pitD pitOpen marginsOpen margins, ,

iti ititi it

results inDespite Despite advances in dentin bonding systemsadvances in dentin bonding systems

they still do not consistently & reliablythey still do not consistently & reliably sensitivitysensitivity, , interfacial staininginterfacial staining

&& bacterial invasionbacterial invasion

they still do not consistently & reliably they still do not consistently & reliably achieve bond strength to dentine & achieve bond strength to dentine &

cementum that are high enough to prevent cementum that are high enough to prevent & & bacterial invasionbacterial invasionthis occurrencethis occurrence



Postoperative sensitivityPostoperative sensitivityp yp yDecreased wear resistance & other mechanical propertiesDecreased wear resistance & other mechanical properties



Technique sensitivityTechnique sensitivityTechnique sensitivityTechnique sensitivity

T hT hTechnique sensitivityTechnique sensitivityPl h iPl h i

The meticulous operative The meticulous operative Placement techniquePlacement technique

ppprocedures demandedprocedures demandedfor placing thesefor placing theseis for placing these for placing these

restorationsrestorationsis

The most important variable inin clinical success is theclinical success is the (increased chair time)(increased chair time)

requirerequire

((there is little room for errors)there is little room for errors)(increased chair time)(increased chair time)

Indications of resin composites as a Indications of resin composites as a posterior restorative materialposterior restorative material

Limiting the Limiting the size of the size of the outline formoutline form

Factors to be consideredFactors to be consideredEstheticsoutline formoutline form

& & ensuring that most of ensuring that most of thethe occlusal forces are absorbedocclusal forces are absorbed

s csFaciolingual width

Gi i l fthe the occlusal forces are absorbed occlusal forces are absorbed by tooth structureby tooth structure Gingival cavosurface

margin

thth li i lli i l f thf th

Cuspal replacementCentric occlusal stops

areare important toimportant to

the the clinical successclinical success of these of these restorationsrestorations

Centric occlusal stopsClenching or grindingR bb d i l iRubber dam isolation

Factors to be consideredFactors to be consideredFactors to be consideredFactors to be consideredEstheticsEsthetics, should be a prime consideration

Faciolingual widthFaciolingual width, restricted to no more than one third of the intercuspal distance

Gigival cavosurface marginGigival cavosurface margin in class in class 22, should be located on intact enamellocated on intact enamel

Cuspal replacement with resin compositesCuspal replacement with resin composites, is not recommended

Centric occlusal stopsCentric occlusal stops, should be located primarily on tooth structure

Clenching or grindingClenching or grinding, the pt should not exhibit excessive wear from that

Rubber dam isolationisolationRubber dam isolationisolation

Autocured vs lightAutocured vs light cured resin compositescured resin compositesAutocured vs lightAutocured vs light--cured resin compositescured resin composites

In recent years, In recent years, some some cliniciansclinicians

The primary The primary advantageadvantage of an of an autocured materialautocured material

have have recommendedrecommended is thatis that

the use of the use of autocured resin autocured resin compositescomposites

it can be placed in bulk, it can be placed in bulk, ddcompositescomposites

(either alone or in (either alone or in bi ti ith VLCbi ti ith VLC

saving time compared to saving time compared to the incremental insertion the incremental insertion

h i d i h Ch i d i h Ccombination with VLC combination with VLC resin composites)resin composites)

technique used with VLC technique used with VLC materialsmaterials

Autocured vs lightAutocured vs light cured resin compositescured resin compositesAutocured vs lightAutocured vs light--cured resin compositescured resin compositesAlthough more timeAlthough more time--consuming, consuming, use of VLC resin composites use of VLC resin composites has has gg g,g, f pf p

a number ofa number of advantages over use of autocured resin advantages over use of autocured resin compositescomposites

VLC i p itVLC i p itAutocured resin compositesAutocured resin composites

pp

VLC resin compositesVLC resin composites

incorporate voidsincorporate voidsachieve achieve

tends to tends to

more complete polymerizationmore complete polymerizationincorporate voidsincorporate voids

(as a result of mixing in two(as a result of mixing in two--paste systems)paste systems)resulting in resulting in

The The increased porosityincreased porositydecreases tensile strengthdecreases tensile strength && surface smoothnesssurface smoothness,,

superior physical propertiessuperior physical properties&& better color stabilitybetter color stability

The The increased porosityincreased porositydecreases tensile strengthdecreases tensile strength && surface smoothnesssurface smoothnessdecreases tensile strengthdecreases tensile strength & & surface smoothnesssurface smoothness, ,

accelerating wearaccelerating wear& & better color stabilitybetter color stability decreases tensile strengthdecreases tensile strength & & surface smoothnesssurface smoothness, ,

accelerating wearaccelerating wear

Direct posterior resin composite Direct posterior resin composite restorationsrestorations

P ti l tiP ti l tiPreoperative evaluationPreoperative evaluationThe The occlusionocclusion

should be marked withshould be marked with articulating paperarticulating paper asasshould be marked with should be marked with articulating paperarticulating paper as as a guide to preparation designa guide to preparation design

At p tAt p t th h il fill dth h il fill d hybrid hybrid

A shade is chosen from the A shade is chosen from the h d idh d id h i hh i h

At present,At present, the heavily filled the heavily filled hybrid hybrid compositescomposites, , with a mean particle size with a mean particle size

of of 1 1 to to 3 3 µm, µm, 1.1. shade guideshade guide that accompanies the that accompanies the

composite, composite, 2.2. then then small portion of the composite is small portion of the composite is

placed onplaced on the unprepared &the unprepared &

are considered are considered best suited for posterior usebest suited for posterior use

Shade selectionShade selection placed onplaced on the unprepared & the unprepared & unetched tooth & polymerizedunetched tooth & polymerized

Shade selectionShade selectionshould be performed should be performed before isolation of the before isolation of the

toothtooth, , because isolated teeth become because isolated teeth become d h d t d & d h d ti hd h d t d & d h d ti hdehydrated, & dehydration changes dehydrated, & dehydration changes

the shade of enamelthe shade of enamel

Direct posterior resin composite Direct posterior resin composite restorationsrestorations

IsolationIsolationIsolationIsolationPlacement of rubber damPlacement of rubber dam

is is mandatorymandatory((failure to maintain a dry field will result failure to maintain a dry field will result

in clinical failure)in clinical failure)

The rubber dam The rubber dam Prevents moisture contaminationPrevents moisture contamination

& & protects gingival tissuesprotects gingival tissues

Documents

Direct Posterior Resin Composites (I) · Conservation of tooth structureConservation of tooth structure TheadhesivepreparationThe adhesive preparation Narrower outline form this prep