Reducing the surface roughness of dental acrylic resins by using an eggshell abrasive material

Statement of problem Excessive surface roughness of denture base resins adversely impacts oral health. Purpose The purpose of this in vitro study was to examine the abrasive potential of eggshell powder in reducing the surface roughness of denture base resins. Material and methods Thirty poly(methyl methacrylate) specimens were fabricated and polished with eggshell powders of different particle sizes and with pumice. The average surface roughness (R_a) after polishing was measured with a profilometer. Scanning electron microscope and optical electron microscope techniques were used to assess the surface roughness morphology of the specimens. ANOVA was used to analyze the R_a values. The Tukey honest significant differences and Bonferroni tests were used to identify differences between the 2 abrasive materials (α=.05). Results Significant differences in the R_a values were observed between the fine and medium eggshell powder abrasives (P<.05). Similarly, significant differences were found between pumice and the fine eggshell powder abrasives (P<.001). No significant differences were found between pumice and the medium eggshell powder abrasive (P>.05). Specimens polished with pumice had the highest R_a values, whereas specimens polished with the fine eggshell powder abrasive had the lowest R_a values. Conclusions By connecting the R_a values to the threshold limit value of 0.2 μm, eggshell powder abrasive finished denture acrylic resin surfaces better than pumice.