Dental Ceramics after Grinding and Polishing Treatments

Abstract

Background: The longevity and aesthetic quality of dental ceramics heavily depend on their surface characteristics, particularly surface roughness, which is influenced by grinding and polishing treatments. Understanding how different polishing systems affect the surface integrity of various ceramic materials is crucial for optimizing restorative dental procedures. Objective: This study aimed to evaluate the effect of different grinding and polishing systems on the surface roughness and morphology of commonly used dental ceramics: feldspathic porcelain, lithium disilicate, and zirconia. Method: A total of 120 ceramic specimens (15 mm × 20 mm × 2 mm) were fabricated from feldspathic porcelain, lithium disilicate, and zirconia. Each material group was randomly divided into subgroups, with each subgroup receiving a specific polishing system (System A, B, or C), including a control group with no polishing. The specimens underwent grinding using fine diamond burs followed by polishing. Surface roughness (Ra) was measured using a contact profilometer, and surface morphology was analyzed through Scanning Electron Microscopy (SEM). Additionally, Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) were used to assess the elemental and crystalline composition of the polishing systems. Results: Polishing System B significantly reduced the surface roughness (Ra) across all ceramic types, producing the smoothest surfaces. System A showed moderate results, while System C was the least effective in reducing roughness. SEM analysis revealed that System B produced minimal surface defects, particularly in zirconia and lithium disilicate. Statistical analysis using ANOVA confirmed significant differences in surface roughness between the polishing systems (p < 0.05). Post hoc tests further supported these findings, with System B outperforming others in terms of surface smoothness. Conclusion: Polishing System B demonstrated superior performance in reducing surface roughness and improving surface morphology in dental ceramics, especially for zirconia and lithium disilicate. These findings highlight the importance of selecting the appropriate polishing system based on the ceramic material used in restorative dentistry. Further studies should explore the long-term clinical durability of these polished surfaces.