Degradation of thermo-mechanically loaded adhesive Class V restorations after 18 months of water storage.
OBJECTIVE
To assess in vitro the hydrolytic stability of adhesive systems in Class V composite restorations bonded to enamel and dentin.


METHODS
16 groups of Class V cavities restored with different adhesive systems and challenged with thermal and mechanical loading under the simulation of dentin fluid were evaluated after an 18-month period of water storage at 37 degrees C. The marginal adaptation of these restorations was quantified by evaluation of gold-coated epoxy replicas with scanning electron microscopy at x200 magnification.


RESULTS
The percentages of "continuous margin" after 18 months of water storage with respect to the total marginal length ranged from 62.9 (5.4)% to 18.5 (3.2)% with significant differences observed among the groups (Bonferroni test P < 0.05). The range in enamel was from 71.8 (14.2)% to 8.9 (6.4)% and in dentin from 94.3 (5.1)% to 0.0 (0.0)%. Marginal adaptation of all the materials tested was affected by water storage, either in enamel, in dentin, or both. None of the restorative systems tested exhibited hydrolytically stable marginal adaptation.
Bortolotto
Tissiana
T
Division of Cariology and Endodontology, School of Dentistry, University of Geneva, 19, Rue Barthélemy-Menn, CH-1205 Geneva, Switzerland.
Ferrari
Marco
M
Tay
Franklin
F
Krejci
Ivo
I
D000269:Adhesives / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D014867:Water / Q000009:adverse effects*
D000269:Adhesives; D017220:Dentin-Bonding Agents; D014867:Water