Comparison of the Effect of Three methods of Porcelain Surface Treatment on Shear Bond Strength of Composite to Porcelain

Background and Aim: Several methods are available for intraoral repair of chipped porcelain restorations by composite resin. Also, there is still controversy regarding the best method of porcelain repair in terms of bond strength and cost effectiveness. This study aimed to compare three methods of porcelain surface treatment on shear bond strength (SBS) of composite to porcelain. Materials and Methods: This in vitro, experimental study was conducted on 30 porcelain blocks with a metal base in three groups. In group 1, porcelain surface was etched with hydrofluoric (HF) acid and silanized. After the application of bonding agent, several composite increments with 2mm thickness were applied on the porcelain surface. In group 2, porcelain surface was sandblasted with 50µaluminum oxide particles, etched and silanized. In group 3, grooves with 2mm length and 0.5 mm depth were created on the porcelain surface. The surface was then etched and silanized. Bonding agent and composite were then applied. The samples were then mounted in acrylic resin, stored in water for one week and subjected to thermocycling. The SBS was then measured using a universal testing machine. The SBS data were compared among the three groups using one-way ANOVA. Results: The mean SBS was 9.13±6.09, 12.71±9.82 and 11.44±7.37 MPa in groups 1-3, respectively. No significant difference in bond strength was noted among the three groups (P>0.05). Conclusion: No significant difference exists among the three surface treatment methods evaluated in this study in terms of SBS of composite to porcelain.