Microbial adherence and surface roughness of denture base materials: An in vitro study

Implant-supported overdentures have become a widely accepted treatment modality for edentulous patients, offering enhanced retention, stability and comfort compared to conventional complete dentures. Hence, a total of 78 standardized specimens were fabricated and divided into three groups (n = 26 each): Group A (heat-cured PMMA), Group B (CAD/CAM milled resin) and Group C (3D-printed resin). Group B exhibited the lowest surface roughness (0.62 ± 0.12 µm) and microbial adherence (0.41 ± 0.09 OD), followed by Group C (1.25 ± 0.18 µm Ra; 0.68 ± 0.12 OD), while Group A showed the highest values (1.82 ± 0.23 µm Ra; 0.91 ± 0.15 OD). All intergroup comparisons were statistically significant (p < 0.001). A strong positive correlation (r = 0.86, p < 0.001) was observed between surface roughness and microbial adherence. It is concluded that CAD/CAM milled resin offers superior surface smoothness and reduced microbial adherence compared to heat-cured PMMA and 3D-printed resins.