Optimization of Heat-Dried Silane Application for CAD/CAM Ceramic Resin Bonding

Abstract

Purpose. Evaluate surface treatments and silane application methods and their effect on shear bond strength (SBS) before and after aging. Materials and methods. Slices of IPS e.max CAD and Vitablocs Mark II, were embedded in acrylic resin. The block was randomly assigned to 5 groups; E:etching with hydrofluoric acid (HF), rinsing, followed by cleaning in ultrasonic bath; E/S:HFetching and cleaned as group E followed by silane application for 20s, air drying and hot drying; E/S+:HFetching and cleaned as group E, followed by silane application for 60s, air drying and hot air drying, rinsing with boiling water and hot air drying; S:silane application for 20s followed by air drying and hot air drying; S+:silane application for 60s followed by air drying, air drying and hot air drying, rinsing in boiling water and hot drying. Cylinders of composite resin (n=12) were bonded with adhesive. SBS testing was carried out after 24h or after thermocycling for groups E; E/S and E/S+. Results. For 24h SBS showed significantly higher mean bond strength with E/S, for both ceramic, compared to E and E/S+. The use of silane alone showed significantly lower mean bond strength. No significant differences were found between E/S and E/S+ for VITA. The SBS was negatively affected by simulated aging in E/S group and positively in E/S+. Conclusions. The association of HFetching and a heat-dried silane showed to be significant to obtain a high SBS. Furthermore, the optimized silane application is not relevant to the immediate SBS while it enhances after aging.