INVESTIGATION OF THE EFFECT OF DIFFERENT POLISHING TECHNIQUES ON THE SURFACE ROUGHNESS OF DENTURE BASE AND REPAIR MATERIALS

Statement of problem. The rough surface of denture base materials may cause plaque accumulation and staining. Thus, the effectiveness of polishing techniques should be known. Purpose. The purpose of this study was to compare the effects of chairside polishing kits and conventional laboratory techniques on the surface roughness of denture base and repair materials. Material and methods. Ninety-six specimens, 50 +/- 1 mm in diameter and 0.5 +/- 0.05 thick, were fabricated from heat-polymerized acrylic resin (HP), polyamide resin (PR), and autopolymerizing resin (AP) and submitted to grinding with a tungsten carbide bur. The specimens were divided into 4 groups according to the polishing technique used: control group without polishing, conventional laboratory polishing, polished with Acrylic Polisher HP blue kit, and polished with AcryPoint polishing kit. Surface roughness (R-a) was measured after polishing with a profilometer. Data were analyzed with a 2-way analysis of variance, and the Tukey honestly significant difference (HSD) test was performed to identify significant differences (alpha=.05). Results. The polishing techniques significantly affected the R-a of denture base materials (P<.001). The highest mean average R-a was measured for the control group. The lowest R-a values were determined in specimens exposed to conventional laboratory polishing techniques. No significant differences were found between Acrylic Polisher HP blue and AcryPoint polishing kits (P>.05). Statistically significant differences were found in the R-a between the PR and both the HP and AP (P<.001); PR exhibited the highest R-a values. Conclusions. Conventional laboratory polishing was the most effective polishing technique. A significantly smoother surface than that of the specimens in the control group was produced with chairside silicone polishing kits.