Surface Evaluation of Polishing Techniques
DiaShine Proven to produce statistically significantly smoother surfaces of New Resilient CAD/CAM Restorative Materials when compared with glazed controls.
Purpose: The purpose of this study was to measure the surface roughness of milled chairside computer-assisted design/computer assisted machining (CAD/CAM) restorations using several contouring/polishing systems as to their effectiveness for creating a clinically acceptable surface.
Materials and Methods: One hundred onlays were milled from monolithic CAD/CAM blocks with an MCXL milling chamber (Sirona Dental) as follows: 30 resin nano-ceramic (Lava Ultimate, 3M ESPE), 30 hybrid ceramic (Enamic, Vita) and 40 leucite-reinforced ceramic (EmpressCAD, Ivoclar). A single group of EmpressCAD onlays was glazed-fired in a porcelain oven (Programat CS2, Ivoclar). Finishing and polishing systems consisted of either an abrasive-polish technique or a brush-polish technique. Roughness values were measured using a three-dimensional measuring laser microscope (OLS4000 LEXT by Olympus).
Results: There was a significant difference in the baseline surface roughness of the CAD/CAM materials (p ≤ 0.05), with the resin nano-ceramic (Lava Ultimate) being smoother than the hybrid ceramic (Enamic), and both being smoother than the leucite-reinforced ceramic (EmpressCAD). All polishing techniques resulted in a smoother surface compared with the baseline surface for the leucite-reinforced ceramic (p ≤ 0.05), with both techniques resulting in a significantly smoother surface than glazing in a porcelain oven (p ≤ 0.05). Both polishing techniques resulted in a smoother surface compared with the baseline surface for both the nano-ceramic and hybrid ceramic materials (p ≤ 0.05).
Conclusions:
Within the limits of this in vitro study: The use of various finishing/polishing techniques on a leucite reinforced ceramic CAD/CAM restorative material produced statistically significantly smoother surfaces when compared with glazed controls (p < 0.05). It is possible to create equally smooth surfaces for the resilient chairside CAD/CAM materials as the chairside CAD/CAM ceramic using several finishing and polishing techniques. No statistically significant difference was found between brush/paste and abrasive rubber polisher systems with a potential clinical advantage noted to the brush/paste system, as it is less likely to inadvertently flatten the porcelain surface.
Clinical Significance: The results of the study indicate that it is possible to create an equally smooth surface for chairside CAD/CAM resilient materials compared with milled ceramics using several finishing and polishing techniques. In addition, both polishing techniques resulted in smoother ceramic surfaces when compared to glazed ceramic surfaces.The polished surface of the ceramic material was smoother than the glazed ceramic surface.