Effect of a silicon carbide bur on shear bond strength between resin cement and zirconia.

PURPOSE: This in-vitro pilot study aimed to investigate the effect of a silicon carbide grinding bur on the shear bond strength (SBS) between zirconia and 10-MDP-containing cement. MATERIALS AND METHODS: Thirty zirconia specimens were prepared and randomly assigned to three groups based on surface pretreatment: airborne-particle abrasion with aluminum oxide particles (APA), treatment with a silicon carbide grinding bur (SiC bur), and airborne-particle abrasion followed by silicon carbide bur treatment (APA + SiC bur). All specimens were bonded with an adhesive resin cement (PANAVIA V5), aged with 5,000 thermocycles, and subjected to an SBS test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's post hoc test (α = 0.05). Fracture modes were assessed. RESULTS: The APA group showed significantly higher SBS than the SiC bur and APA + SiC bur groups (p < 0.001). The APA + SiC bur group showed a higher mean SBS than the SiC bur group, but the difference was not statistically significant (p > 0.05). CONCLUSION: Silicon carbide bur treatment did not have a beneficial effect on SBS after 5,000 thermocycles. Airborne-particle abrasion resulted in significantly higher SBS than silicon carbide bur treatment alone or airborne-particle abrasion followed by silicon carbide bur treatment. CLINICAL RELEVANCE: Under the tested conditions, the silicon carbide bur cannot be recommended as an alternative or an adjunct to airborne-particle abrasion for improving zirconia-resin cement bonding.