The effect of different grinding types on metal-ceramic adhesion

Abstract

Objective

The strong bond strength (SBS) between metal and ceramic is crucial to the success and longevity of metal-ceramic restorations. Therefore, this study aimed to determine the SBS between ceramic and cobalt-chromium (Co-Cr) alloys produced by different methods, treated with sandblasting, and four different grinding procedures.

Materials and methods

A total of one hundred and fifty Co-Cr samples were produced, including fifty samples from each group using casting, laser sintering, and milling techniques. The produced samples were divided into five subgroups according to their main groups. The sample groups were ground in one direction with a sintered diamond bur, carbide bur, pink stone, carbon separating disc, and the other group was sandblasted with 110 μm Al₂O₃. After surface treatments, an SBS test was performed, and the data were analyzed by one-way statistical analysis of variance (ANOVA) and Tukey HSD comparison test (p > .05). Surface characterizations of Co-Cr alloys were also examined with digital microscopy after debonding.

Results

There was a statistical difference between the laser sintering and milling groups compared to the fabrication techniques. While the highest SBS value was determined in milling groups (16.85 ± 2.63) with Al₂O₃ sandblasting, the lowest was found in the casting group (8.97 ± 3.35) with Al₂O₃ sandblasting. The use of abrasive burs with different surface properties and sandblasting used in metal leveling and finishing surface preparation significantly changes the ceramic's adhesion to the metal surface.

Keywords:

• Shear strength
• metal-ceramic alloy
• chromium-cobalt alloys
• metal-ceramic restorations

Disclosure statement

No potential conflict of interest was reported by the author.