Adhesion of resin cement to contemporary hybrid ceramic and polymeric CAD/CAM materials: effect of conditioning methods and ageing

摘要

This study assessed the effect of different surface conditioning methods and ageing protocols on adhesion of resin cement to hybrid ceramic and polymeric CAD/CAM materials. CAD/CAM materials (n = 360, n = 30 per group), namely (a) Lithium disilicate (IPS e.max CAD-LIS), (b) Zirconia (IPS e.max ZirCAD-ZIR), (c) Polymer (Lava Ultimate-LAV), (d) Polymer infiltrated ceramic network (Enamic-ENA), (e) Polymer infiltrated ceramic (Experimental-1-CS1), (f) Polymer infiltrated ceramic (Experimental-2-CS2), (g) Lithium disilicate reinforced alumina (n!ce-NIC) were cut into slices (3 x 6 x 8 mm(3)) and conditioned: (a) Method 1: 5% hydrofluoric acid etching (H)+silane and (b) Method 2: Silica coating (CoJet (A)+silane). Group LIS was conditioned with only Method 1 and Group ZIR only with Method 2 (control). Resin cement (Variolink Esthetic II) was bonded onto the conditioned specimens and photopolymerized. One-half of the specimens was subjected to ageing (thermocycling 5-55 degrees, 5000 cycles) and the other half was stored in distilled water (37 degrees C, 24 h). The resin-substrate interface was loaded under shear forces in a Universal Testing Machine (1 mm/min). Data (MPa) were analyzed using two-way ANOVA and Tukey`s tests (alpha = 0.05). Substrate type, conditioning method and ageing had a significant effect on adhesion values (p < .05). In aged conditions, ENA-H, ENA-A, LAV-H, LAV-A, CS2-A (15 +/- 4 - 11.6 +/- 5) showed no significant difference (p > .05), with the CS2-A (15 +/- 4) showing the least reduction (5.5%) compared to all other groups (5.8-62.6%). CS1-A (100%) followed by ENA-H, ENA-A (93%), CS2-A (80%) presented the highest incidence of cohesive failures after ageing.