Presentation on theme: "Resin-modified Glass-ionomer Materials"— Presentation transcript:
1 Resin-modified Glass-ionomer Materials Dent 5801 Operative Dentistry IOct 9th, 2007Resin-modified Glass-ionomer MaterialsDaranee Versluis-TantbirojnDivision of Operative DentistryDepartment of Restorative Sciences
2 Learning objectives Students will be able to Understand clinical behavior of glass-ionomers from the material viewpointApply scientific information from the literature for clinical decisions about the use of glass-ionomersAppropriately use glass-ionomers in restorative dentistry
3 + pendant methacrylate groups Recall...DENT 5351 Dental cements, Dr. Combe, Feb 2, 2007+ pendant methacrylate groupsPolymerizationResin-modifiedglass-ionomerAcid-base reaction
4 Background: Chemistry and setting reactions polyalkenoic acids + calcium fluoroalumino silicate glass+ methacrylatecopolymerGlasscoreTooth structureCa2+Al3+F-CO-O--O-COPO43-Siliceous hydrogelCa/Al polyacrylatematrixConventional GIs(Acid-based reaction)Ca2+ = initial set (minutes)Al3+ = final set (days, weeks, months)Resin-modified GIsLight initiated or autocure (set w/o light)methacrylatecopolymer(resin-modified GI)Drawing adapted fromAlbers HF 1996, Tooth-color Restoratives.
5 True glass ionomers Conventional or Resin-modified Mixing ‘self-cured’‘light-cured’Resin-modifiedacid-base reactionMixingCure in the dark
8 Glass ionomers in restorative dentistry **RestorativeFuji II LCFuji IXKetac MolarKetac Fil(Filling)VitrebondLining**Vitrebond PlusKetac BondFuji LiningLutingRelyX LutingRelyX Luting Plus*FujiPlusFujiCem**presently used in Operative preclinic & clinic
9 Advantages of glass ionomers Compare with other cements Ion exchange layerAdhesion to tooth structuresGlasscoreTooth structureCa2+Al3+F-CO-O--O-COPO43-Release ions (F-) affect balance between de/remin‘Non-irritant’TranslucentBetter mechanical propertiesCompare with other cements
10 Glass ionomers: Use with caution Inadequate physical properties *Sensitive to water gain/loss *Esthetic compromise *Anticaries property is questionedAdhesion property is not comparable to composite + dentin adhesive* More crucial if used as a permanent filling material
11 Major physical failure GIs cannot be used as permanent restorative material in stress-bearing areasMajor physical failure58 monthsBulk fractureMarginal fracturePoor anatomic form (wear)Dissolution/disintegrationClinical failure of class-II restorations of a highly viscous glass-ionomer material over a 6-year period: A retrospective studyScholtanus JD, Huysmans MCDNJMJ Dent 2007;35:156-62Esthetic compromiseOpaqueSurface finish
12 Sensitive to water gain/loss Use with cautionsSensitive to water gain/lossMaintain water balance during initial settingResin-modified GI restoratives (GC Fuji II LC)Resin protects cement from waterFast-set GIs (GC Fuji IX)Wait 3-6 min before polishingPolish with water coolant to prevent dehydrationApply unfilled resin to protect surface
13 How is it under clinical conditions? Anticaries property is questioned?In vitro anticariogenic potential of GIs is knownAdapted from HicksPlaque or acid mediumVitrebond Plus/Z250Z250How is it under clinical conditions?
14 Anticaries property Questionable? A systemic review shows no overall evidence for or against a treatment effect of inhibition of secondary caries by glass ionomer restoration28 studies from 1970 to 1996; total of 3965 participants; high caries risk5 positive studiesNo secondary caries in GI; secondary caries in control19 neutral studiesNo secondary caries in either groupor secondary caries present in both groups4 negative studiesSecondary caries in GI; no secondary caries in controlRandall RC, Wilson NH. J Dent Res 1999;78:How would the data apply to present glass ionomers?
15 Anticaries property Questionable? Glass ionomers reduce recurrent caries in high-risk patients who do not routinely use topical fluoride.Restorations in xerostomic patients: composite or amalgam vs GIPatients were instructed to use NaF gel dailyAt 2 years recall:No recurrent caries was found in the fluoride usersNo recurrent caries associated with conventional GIIn fluoride non-users, 8 composite and 1 RMGI had recurrent caries & higher incidence of caries at amalgam cavosurface marginsMcComb D, Erickson RL, Maxymiw WG, Wood REOperative Dentistry 2002;27:430-7Haveman CW, Summitt JB, Burgess JO, Carlson KJADA 2003;134:177-84
16 Use GI restorative material for caries control G. Mount67 Cl V composite and 65 Cl V glass ionomer cementAfter 5 years, 1% of glass ionomer and 6% of composite restorations had become cariousApproximately twice as much marginal staining around the composite as around the glass ionomers.Tyas MJ. Australian Dental Journal 1991; 36:236-9.Cariostatic effect of glass ionomer cement: a five-year clinical study.
18 Bond strengths of glass ionomers are not comparable to composite + adhesive or resin cement Should I use GI luting cement or resin cement?Should I use GI restorative or composite?Should I use GI liner or not?What are the most likely errors that affect adhesion?Other issues to consider related to adhesion:post-operative sensitivitymicroleakagepulp protection
19 Studies showed that GI lutings did not cause post-op sensitivity. GI luting vs Resin cementPost-operative sensitivity was a problem with GI lutings in 1980’s–1990’sStudies showed that GI lutings did not cause post-op sensitivity.No differences between GICs (conventional & resin-modified) or a zinc phosphate luting cementKern M, Kleimeier B, Schaller HG, Strub JR. J Prosthet Dent 1996;75:159-62Jokstad A. Int J Prosth 2004;17:411-6Paste-paste resin-modified GI luting cement did not cause post- operative sensitivity (290 restorations in 268 patients) .Yoneda S, Morigami M, Sugizaki J, Yamada T. Quintessence Int. 2005;36:49-53The level of tooth sensitivity post-cementation (1-4 wks) was less than pre-operatively in both conventional and resin-modified GICs.Smales RJ, Gale MS. Oper Dent 2002;27:442-6
20 Should I use GI luting cement or resin cement? GI luting vs Resin cementPost-operative sensitivity was a problem with GI because:Dentin was desiccatedAnhydrous glass ionomer cementShould I use GI luting cement or resin cement?GI luting cement for indirect metal restoration (inlays, onlays, full gold crown) and PFM.Simple application & easy clean upResin cement for esthetic indirect restorations (porcelain, ceramics, indirect composite) and indirect metal or PFM where additional retention is required (minimal tooth structure).Indications
21 Example of instruction for use of a resin-modified glass-ionomer luting cement (3M RelyX Luting Plus)Pulp protection if necessaryClean tooth, rinse and lightly dry leaving tooth surface moist.Remove excess cement at a waxy stage (after 2 minutes from placement)Mix with spatula for 20 secondWorking time 2.5 minutes
22 Should I use GI restorative or composite? Clinical studies showed mixed results in Cl V retentionFolwaczny et al., 2001Brackett et al., 2003Onal and Pamir, 2005868170CompositeRMGI3 years2 years% Retention5596100ReferencesHowever, deficiencies in color stability, anatomic form, or wear limit the longevity of glass ionomer restorations.Post-operative sensitivity of composite restorationsPolymerization shrinkageMicroleakageSub-optimal bonding
23 Painful on pressure Composite leakage & Post-op sensitivity Post-operative sensitivityComposite leakage& Post-op sensitivityAnecdote:No sensitivity after replacing composite with glass ionomer restorationPainfulon pressure
24 Example of resin-modified glass-ionomer restorative (GC Fuji II LC) Cavity conditioner (recommended for GC products)Enhanced bonding by removing smear layerMild (25%) polyacrylic acidApply 10 seconds on dentin and enamel, rinse, blot. Surfaces should appear moist (glistening) before applying glass ionomer
25 However, GI liners prevent post-operative sensitivity. Should I use GI liner?Bond strength (MPa)*EnamelDentinComposite + adhesive~ 30~ 25GI liner~ 3-7~ 4-10Bond strength of GI liner is not comparable to compositeHowever, GI liners prevent post-operative sensitivity.When GI liner (e.g., Vitrebond or Fuji Lining Cement) is applied to the deepest portions of Class I, II, and V tooth preparations before any bonding systems are used, clinicians have reported that it almost totally prevents postoperative tooth sensitivity.Gordon J Christensen, JADA 2002;133:
26 Should I use GI liner? Less microleakage with GI liners Class II amalgam restorations with GI liners had significantly less microleakage than did restorations with calcium hydroxide liners or dentin alone (without GI).Rabchinsky J, Donly KJ. Int J Perio Rest Dent 1993;13:378-83Marchiori S et al., Quintessence Int 1998;29:637-42‘Dycal’ should always be covered with GI linerCa(OH)2 liner adversely affects bonding efficacy of dentin adhesiveKrejci I, Lutz F, J Dent 1990;18:263-70Ca(OH)2 liners ‘wash out’ leaving a void underneath the restorationNovickas D, Fiocca VL, Grajower R, Oper Dent 1989;14:33-9How good is Dycal to withstand amalgam condensation?
27 Should I use GI liner? Do not use RMGI when pulp is exposed. When in direct contact with exposed pulp,Vitrebond triggered a persistent inflammatory reaction.Am J Dent 2000;13:28-34do Nascimento AB, Fontana UF, Teixeira HM, Costa CABiocompatibility of a RMGIC applied as pulp capping in human teethBut GI liner is better than dentin adhesive in deep cavity.Pulp response in deep class V composite restoration lined with Vitrebond was better than total-etched adhesive.Dent Mater 2003;19:739-46Costa CA, Giro EM, do Nascimento AB, Teixeira HM, Hebling JShort-term evaluation of the pulpo-dentin complex response to a resin-modified glass-ionomer cement and a bonding agent applied in deep cavities.
28 How deep is deep? ~ 1 mm below DEJ* 1-2 mm from pulp* >1 mm from DEJ*0.5-1 mm from pulp*(‘pinkish’)GI liner optionalEtch & AdhesiveCompositeGI linerEtch & AdhesiveCompositeDycalGI linerEtch & AdhesiveComposite* The numbers are arbitrary for illustration purposes.It depends on the tooth, location, pulp recession, etc.
29 Example of resin-modified glass-ionomer liner (3M Vitrebond Plus) Use clean Dycal carrierFollowed by etching, bonding, filling