A Study On The Polishing Performance Of Different Polishing Tools For E.max CAD Glass-ceramic

ObjectiveThe purpose of this study was to compare the polishing performance of five different glass-ceramic polishing tools on e.max CAD glass-ceramic by surface roughness,glossiness,scanning electron microscope(SEM)observing and provide evidence for clinical polishing tool selection.MethodsPreparing sixty e.max CAD glass-ceramic specimens which size was 15mm* 10mm*5mm,then divided these specimens into 6 groups and measured surface roughness and glossiness after grinding with waterproof sandpaper and diamond bur.These specimens received different surface treatments when statistical results of every group were consistent with each other.The surface treatments including glazing(group G),polishing with Shofu polishing set,that is,Porcelain Adjustment Kit+Cera Master(group SF),3M Sof-LexTM Discs(group 3M),Toboo M polishing system(group Tob),EVE DIAPRO system(group EVE),and Ivoclar Vivadent Optra Fine system(group Ivo).Polishing quality was measured with vancometer and profilometer,and we selected glossiness,Ra and Rz values for statistical analysis.Qualitative surface evaluation was performed through SEM.ResultsThe mean glossiness values of each group were as follows: G(68.4GU±1.5G U)>3M(58.4GU±2GU)>Ivo(55.7GU±3.7GU)>SF(47.5GU±3.3GU)>EVE(40.7GU±4.6GU)>Tob(32.2GU±3.5GU).No significant difference was observed between 3M and Ivo groups(P>0.05),but the remaining treatment groups were significantly different from each other(P<0.05).As for surface roughness results,the mean Ra values of each group were as follows: 3M(0.202 μm±0.034 μm)<G(0.227 μm±0.014 μm)<SF(0.287 μm±0.02μm)<Ivo(0.32 μm±0.012 μm)<EVE(0.471 μm±0.044 μm)< Tob(0.567μm±0.028 μm).No significant difference was observed between 3M and G gruops(P>0.05), and SF and Ivo groups(P>0.05),but the remaining treatment groups were significantly different from each other(P<0.05).Statistical results of Rz values were the same as the Ra values,and visual analysis of the images obtained from SEM was consistent with the surface roughness statistical results.ConclusionsThe polishing performance of different polishing tools for e.max CAD glass-ceramic was different.Sof-LexTM Discs achieved the best performance,which was comparable to that of glazing.The polishing effects of Shofu polishing set and Optra Fine system were better than EVE DIAPRO system’s.Toboo M polishing system didn’t achieve good performance.