Effects of different demineralization-inhibiting methods on the shear bond strength of glass-ceramics

PurposeThis in vitro study was undertaken to evaluate the effects of different demineralization-inhibiting methods on the shear bond strength (SBS) of glass-ceramics. Materials and MethodsNinety extracted intact human mandibular lateral insicors were randomly divided into six equal groups. Group C was left untreated, while enamel subsurface demineralization was induced in the other groups. In group D, porcelain discs (3 mm in diameter) were cemented to demineralized enamel by using total-etch photopolymerizing luting composite resin without pretreatment. Demineralized specimens in groups F, CA, M, and I were pretreated with fluoride gel, CPP-ACP paste, microabrasion, and resin infiltration, respectively, and then porcelain discs were cemented. SBS (MPa) was calculated from the failure load (N) per bonded area (mm(2)). Fracture types were examined by optical microscopy (40x magnification). Data were analyzed with ANOVA, Tukey's test, and G-test. ResultsANOVA revealed significant intergroup differences (p < 0.01). No significant differences in SBS (MPa) were found between groups C (19.48 2.0) and I (20.02 +/- 1.6). Lower SBS values were recorded in groups D (7.93 +/- 0.8), F (12.51 +/- 1.5), CA (17.08 +/- 1.3), and M (14.84 +/- 1.4). Mixed and cohesive failures were the most prevalent in groups M and I, respectively. ConclusionResin infiltration enhanced the SBS of porcelain discs bonded to demineralized enamel when compared with the other demineralization-inhibiting methods. Clinical Relevance: Resin infiltration could be useful to enhance adhesion of glass-ceramics to teeth with white spot lesions.