Effects of Disinfectant Solutions Against COVID-19 on Surface Roughness, Gloss, and Color of Removable Denture Materials

The objective of this study was to investigate the effect of surface disinfectant solutions against COVID-19 on the surface roughness, gloss, and color of removable denture materials. Fifty rectangular metallic specimens made of Co-Cr alloy and fifty disk-shaped specimens made of PMMA were prepared according to the manufacturers' instructions. Fifty maxillary right central incisors were also included in the study. The above-mentioned specimens were equally divided into five groups (n = 10). Four disinfectant solutions were tested (0.1 wt% NaOCl, 0.5 wt% H₂O₂, 78 wt% ethanol, and 1 wt% Povidone Iodine), and freshly distilled water was used as the control. To simulate clinical practice, each specimen was immersed in the disinfectant solution 15 times. All specimens were marked, and surface roughness, gloss, and color were measured before and after immersion. All roughness parameters (Sa, Sq, Sz, Sc, and Sv) and gloss values before and after immersion were statistically compared. ΔE*ab values were statistically compared with perception and acceptability thresholds according to ISO/TR 28642. No significant differences were identified for surface roughness parameters for all groups tested. All materials demonstrated a significant increase in gloss after aging regime, while only the metallic specimens illustrated ΔE*ab values higher than the acceptability threshold after disinfection with H₂O₂. None of the surface properties deteriorated after exposure to tested disinfectants, and thus, all of them can be effectively implemented in everyday practice.