Surface roughness of a feldspathic dental porcelain after simulation of occlusal adjustment and polishing

Abstract

Purpose: The aim of this study was to evaluate the surface roughness (Ra) of a feldspathic dental porcelain (IPS Classic Ivoclar) subjected to two polishing systems after simulation of occlusal adjustment. Methods: Twenty disk-shaped feldspathic ceramic (IPS Classic Ivoclar) specimens were fabricated according to the manufacturer instructions and divided into two groups (A and B). The baseline surface roughness (Ra 0) of the glazed specimens was measured using a surface profilometer (Surtronic 3+). The surface was ground with diamond burs (PM82F and 0261PM), and the surface roughness was measured (Ra 1). Group A was treated with the Edenta diamond bur finishing system (EXA-Cerapol #352, #362 and Cerapol Super #372), and Group B was treated with the Tri Hawk silicon tip polishing system (Universal Fase 1 and Fase 2) before the final surface roughness measurement (Ra 2). Data were analyzed by ANOVA and Tukey’s test at the 5% significance level. Results: Surface roughness mean and standard deviation values (in micrometer) were: Group A – Ra 0=0.21±0.07, Ra 1=0.66±0.07, Ra 2=0.23±0.07; and Group B – Ra 0=0.20±0.04, Ra 1=0.72±0.06, Ra 2=0.21±0.05). No significant differences were found between the polished groups and the glazed surface. Conclusion: According to the methods used, both polishing systems provided surface roughness similar to that of the original glazed surface. Key words: Polishing; porcelain; roughness