Method: Forty-two maxillary premolar porcelain denture teeth (Unilux-Enta Lactona) embedded in acrylic blocks and the coronal one-third of teeth were removed perpendicularly to long axis of denture teeth. Porcelain teeth surfaces were ground wet with 600-grit silicon carbide (SiC) paper. They were randomly divided into 6 groups according to the surface treatments (n=7): Group 1: 10% Hydrofluoric acid (HF) + Silane; Group 2: Tribochemical silica coating (CoJet, 3M ESPE) + Silane; Group 3: Er:Cr:YSGG laser (Biolase) etching + Silane; Group 4: Er:Cr:YSGG laser-etch + %10 HF + Silane; Group 5: Sandblasting (SB)+Silane; Group 6: SB+ 10 %HF + Silane. The Er:Cr:YSGG laser etching was performed with the settings; 3W, 20Hz, with air and water cooling. After each surface treatment, an adhesive was applied to the surface and composite resin was incrementally built up. The SBS test was carried out using a universal testing machine (0.5 mm/min). Data were analyzed using Anova and Tukey HSD tests at a significance of p<0.05. SEM analysis was also performed for one specimen of each group after the SBS test to evaluate the nature of the fracture surface and surface texture.
Result: Er:Cr:YSGG laser etched and then silane applied group (G3) showed the highest SBS values (7.7±1.5MPa) and SB with combination silane applied group (G5) showed the lowest (3.9±1.3MPa). However, there were no statistically significant differences in SBS values among all groups (p˃0.05).
Conclusion: Er:Cr:YSGG laser treatment may be an alternative method to Sandblasting, Tribochemical silica coating and HF application for enhancing the bond strength of porcelain denture teeth to composite resin.