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
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
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
Alternative to amalgamAlternative to amalgamgg
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
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
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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))
Conservation of tooth structureConservation of tooth structureConservation of tooth structureConservation of tooth structure
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
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
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
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
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
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
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
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
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
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
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
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 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)
Technique sensitivityTechnique sensitivity
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
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 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)
Technique sensitivityTechnique sensitivity
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
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 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
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 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)
Technique sensitivityTechnique sensitivity
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
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
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
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
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
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 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)
Technique sensitivityTechnique sensitivity
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
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