Presentation on theme: "Daranee Versluis-Tantbirojn Division of Operative Dentistry Department of Restorative Sciences Dent 5801 Operative Dentistry I Oct 9 th, 2007."— Presentation transcript:
Daranee Versluis-Tantbirojn Division of Operative Dentistry Department of Restorative Sciences Dent 5801 Operative Dentistry I Oct 9 th, 2007
Understand clinical behavior of glass-ionomers from the material viewpoint Apply scientific information from the literature for clinical decisions about the use of glass-ionomers Appropriately use glass-ionomers in restorative dentistry Students will be able to
DENT 5351 Dental cements, Dr. Combe, Feb 2, pendant methacrylate groups Resin-modified glass-ionomer
Conventional GIs (Acid-based reaction) polyalkenoic acids + calcium fluoroalumino silicate glass Glass core Tooth structure Ca 2+ Al 3+ F-F- F-F- F-F- F-F- F-F- Ca 2+ Al 3+ CO-O - - O-CO CO-O - - O-CO CO-O - Ca 2+ PO 4 3- CO-O - Siliceous hydrogel Ca/Al polyacrylate matrix Ca 2+ = initial set (minutes) Al 3+ = final set (days, weeks, months) Resin-modified GIs methacrylate copolymer (resin-modified GI) methacrylate copolymer (resin-modified GI) + methacrylate copolymer Light initiated or autocure (set w/o light) Drawing adapted from Albers HF 1996, Tooth-color Restoratives.
True glass ionomers Conventional Resin-modified or ‘self-cured’ ‘light-cured’ Mixing Cure in the dark acid-base reaction
FujiPlus FujiCem RelyX Luting RelyX Luting Plus Fuji II LC Fuji IX Ketac Molar Ketac Fil Ketac Bond Vitrebond Plus Fuji Lining Vitrebond * * * * * * * presently used in Operative preclinic & clinic
‘Non-irritant’ Release ions (F - ) affect balance between de/remin Ion exchange layer Adhesion to tooth structures Translucent Better mechanical properties Compare with other cements
Inadequate physical properties * Sensitive to water gain/loss * Esthetic compromise * Anticaries property is questioned Adhesion property is not comparable to composite + dentin adhesive Glass ionomers: Use with caution * More crucial if used as a permanent filling material
Major physical failure Bulk fracture Marginal fracture Poor anatomic form (wear) Dissolution/disintegration Clinical failure of class-II restorations of a highly viscous glass-ionomer material over a 6-year period: A retrospective study Scholtanus JD, Huysmans MCDNJM J Dent 2007;35: months GIs cannot be used as permanent restorative material in stress-bearing areas Esthetic compromise Opaque Surface finish
Sensitive to water gain/loss Resin-modified GI restoratives (GC Fuji II LC) Resin protects cement from water Fast-set GIs (GC Fuji IX) Wait 3-6 min before polishing Maintain water balance during initial setting Apply unfilled resin to protect surface Use with cautions Polish with water coolant to prevent dehydration
Anticaries property is questioned? In vitro anticariogenic potential of GIs is known Adapted from Hicks Plaque or acid medium Vitrebond Plus/Z250 Z250
Randall RC, Wilson NH. J Dent Res 1999;78: positive studies No secondary caries in GI; secondary caries in control 19 neutral studies No secondary caries in either group or secondary caries present in both groups 4 negative studies Secondary caries in GI; no secondary caries in control 28 studies from 1970 to 1996; total of 3965 participants; high caries risk A systemic review shows no overall evidence for or against a treatment effect of inhibition of secondary caries by glass ionomer restoration Anticaries property Questionable? Anticaries property Questionable? How would the data apply to present glass ionomers?
McComb D, Erickson RL, Maxymiw WG, Wood RE Operative Dentistry 2002;27:430-7 Restorations in xerostomic patients: composite or amalgam vs GI Patients were instructed to use NaF gel daily At 2 years recall: No recurrent caries was found in the fluoride users No recurrent caries associated with conventional GI In fluoride non-users, 8 composite and 1 RMGI had recurrent caries & higher incidence of caries at amalgam cavosurface margins Haveman CW, Summitt JB, Burgess JO, Carlson K JADA 2003;134: Glass ionomers reduce recurrent caries in high-risk patients who do not routinely use topical fluoride. Anticaries property Questionable? Anticaries property Questionable?
G. Mount Use GI restorative material for caries control 67 Cl V composite and 65 Cl V glass ionomer cement After 5 years, 1% of glass ionomer and 6% of composite restorations had become carious Approximately twice as much marginal staining around the composite as around the glass ionomers. Tyas MJ. Australian Dental Journal 1991; 36: Cariostatic effect of glass ionomer cement: a five-year clinical study.
Adhesion property of glass ionomers Bond strength (MPa)*EnamelDentin GI luting cement GI Restorative Composite + adhesive GI liner Resin cement + adhesive MetalPorcelain ~ 25 (etched porcelain & ceramic primer) ~ ~ 30~ 25 ~ 3-7~ 4-10 ~ 6-10~ 2-6 * Shear mode; 3M and GC products; 3M Product Profiles GI luting cement~ 7-12 (sandblast) ~ 8-14 (Zr, Alumina) ~ 4-14~ 4-10
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? Bond strengths of glass ionomers are not comparable to composite + adhesive or resin cement Other issues to consider related to adhesion: post-operative sensitivity microleakage pulp protection
GI luting vs Resin cement Post-operative sensitivity was a problem with GI lutings in 1980’s–1990’s Smales RJ, Gale MS. Oper Dent 2002;27:442-6 No differences between GICs (conventional & resin-modified) or a zinc phosphate luting cement Kern M, Kleimeier B, Schaller HG, Strub JR. J Prosthet Dent 1996;75: Jokstad A. Int J Prosth 2004;17:411-6 The level of tooth sensitivity post-cementation (1-4 wks) was less than pre-operatively in both conventional and resin-modified GICs. Studies showed that GI lutings did not cause post-op sensitivity. Paste-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;36:49-53
GI luting vs Resin cement Post-operative sensitivity was a problem with GI because: Dentin was desiccated Anhydrous glass ionomer cement GI luting cement for indirect metal restoration (inlays, onlays, full gold crown) and PFM. Simple application & easy clean up Resin cement for esthetic indirect restorations (porcelain, ceramics, indirect composite) and indirect metal or PFM where additional retention is required (minimal tooth structure). Should I use GI luting cement or resin cement?
Example of instruction for use of a resin-modified glass- ionomer luting cement (3M RelyX Luting Plus) Remove excess cement at a waxy stage (after 2 minutes from placement) Mix with spatula for 20 second Working time 2.5 minutes Pulp protection if necessary Clean tooth, rinse and lightly dry leaving tooth surface moist.
Post-operative sensitivity of composite restorations Polymerization shrinkage Microleakage Sub-optimal bonding Should I use GI restorative or composite? Clinical studies showed mixed results in Cl V retention Folwaczny et al., 2001 Brackett et al., 2003 Onal and Pamir, CompositeRMGI 3 years 2 years % Retention References However, deficiencies in color stability, anatomic form, or wear limit the longevity of glass ionomer restorations.
Composite leakage & Post-op sensitivity Composite leakage & Post-op sensitivity Post-operative sensitivity Painful on pressure Anecdote: No sensitivity after replacing composite with glass ionomer restoration
Example of resin-modified glass-ionomer restorative (GC Fuji II LC) Enhanced bonding by removing smear layer Mild (25%) polyacrylic acid Apply 10 seconds on dentin and enamel, rinse, blot. Surfaces should appear moist (glistening) before applying glass ionomer Cavity conditioner (recommended for GC products)
Should I use GI liner? Bond strength (MPa)*EnamelDentin Composite + adhesive GI liner ~ 30~ 25 ~ 3-7~ 4-10 Bond strength of GI liner is not comparable to composite 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: However, GI liners prevent post-operative sensitivity.
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). Marchiori S et al., Quintessence Int 1998;29: Rabchinsky J, Donly KJ. Int J Perio Rest Dent 1993;13: Krejci I, Lutz F, J Dent 1990;18: Ca(OH) 2 liner adversely affects bonding efficacy of dentin adhesive Ca(OH) 2 liners ‘wash out’ leaving a void underneath the restoration Novickas D, Fiocca VL, Grajower R, Oper Dent 1989;14:33-9 ‘Dycal’ should always be covered with GI liner How good is Dycal to withstand amalgam condensation?
Dent Mater 2003;19: Costa CA, Giro EM, do Nascimento AB, Teixeira HM, Hebling J Short-term evaluation of the pulpo-dentin complex response to a resin-modified glass-ionomer cement and a bonding agent applied in deep cavities. Pulp response in deep class V composite restoration lined with Vitrebond was better than total-etched adhesive. When in direct contact with exposed pulp, Vitrebond triggered a persistent inflammatory reaction. Am J Dent 2000;13:28-34 do Nascimento AB, Fontana UF, Teixeira HM, Costa CA Biocompatibility of a RMGIC applied as pulp capping in human teeth Do not use RMGI when pulp is exposed. But GI liner is better than dentin adhesive in deep cavity. Should I use GI liner?
How deep is deep? ~ 1 mm below DEJ*0.5-1 mm from pulp* (‘pinkish’) 1-2 mm from pulp* >1 mm from DEJ* GI liner optional Etch & Adhesive Composite GI liner Etch & Adhesive Composite Dycal GI liner Etch & Adhesive Composite * The numbers are arbitrary for illustration purposes. It depends on the tooth, location, pulp recession, etc.
Use clean Dycal carrier Example of resin-modified glass- ionomer liner (3M Vitrebond Plus) Followed by etching, bonding, filling