Evaluation of different surface treatments on the bond strength of CAD/CAM PMMA denture teeth to heat-polymerized acrylic denture base.

This in vitro study aims to evaluate various surface treatments on the shear bond strength and failure mode of CAD/CAM PMMA teeth to the heat-polymerized acrylic denture base. The study sample consisted of 100 teeth that were divided equally into five groups: Group 1: denture artificial teeth (control), Group 2: PMMA teeth without surface treatment, Group 3: PMMA teeth with MMA etching, Group 4: PMMA teeth with sandblasting (aluminum oxide particles), and Group 5: PMMA teeth with perpendicular grooves. The shear bond strength test was performed using a universal testing machine and the failure mode was recorded. Data were analyzed using ANOVA followed by Tukey's post-hoc tests (α = 0.05). MMA increased the shear bond strength compared with other surface treatments (sandblasting and perpendicular grooves; P < 0.001). Sandblasting and perpendicular grooves showed no significant difference in the shear bond strength (P = 0.548 and 0.061; respectively). There were statistically significant differences in the frequencies of failure mode between the studied groups (P < 0.001). The control, PMMA, and PMMA + Sandblasting groups showed the weakest bonding. MMA application improved the shear bond strength for CAD/CAM PMMA teeth, the perpendicular groove seems to be not sufficiently effective, while the sandblasting cannot be considered as a surface treatment.