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A Comparison of the Surface Properties of CAD/CAM and Conventional Polymethylmethacrylate (PMMA).

PURPOSE
To compare surface properties of 2 brands of pre-polymerized resin blocks for complete dentures (CAD/CAM PMMA) to conventional heat-polymerized PMMA.


MATERIALS AND METHODS
A total of 45 rectangular specimens (25 × 25 × 3 mm) were fabricated from 3 brands of PMMA (n = 15/group): AvaDent CAD/CAM PMMA, Tizian-Schütz CAD/CAM PMMA, Meliodent conventional PMMA. Specimens were examined for wettability using the sessile drop method, surface roughness using a digital contact profilometer, and microhardness using Vickers hardness number. Statistical analysis was performed using one-way ANOVA and Tukey pairwise multiple comparisons. p-Values of ≤0.05 were considered significant.


RESULTS
AvaDent specimens demonstrated the highest mean contact angle (72.87 ± 48°) and the highest mean Vickers hardness number (20.62 ± 0.33). The conventional heat-polymerized specimens showed the highest mean surface roughness (0.22 ± 0.071 μm). Tizian-Schütz specimens showed the lowest mean surface roughness (0.12 ± 0.02 μm).


CONCLUSIONS
As CAD/CAM PMMA groups exhibited significantly more favorable surface properties in comparison to the conventional heat-polymerized groups, CAD/CAM dentures are expected to be more durable. Different brands of CAD/CAM PMMA may have inherent variations in surface properties.