Effects Of Different Surface Treatments On Surface Roughness And Bacteria Adhesion Of Zirconia

Objective:This study was to investigate the influence of different surface treatments(sintering,occlusal adjusting,glazing and polishing)on the surface roughness and bacterial adhesion of two zirconia ceramic materials(ZENOSTAR,AIDITE).To explore the two commonly used zirconia ceramic material polishing performance for the zirconia ceramic material surface treatment process to provide clinical guidance.Methods:(1)Two kinds of zirconia ceramic materials(ZENOSTAR,AIDITE),which were commonly used in clinical practice,were cut according to the manufacturer’s instructions CAD / CAM processing,and 120 pieces were prepared with a length of 10 mm × 10 mm × 2 mm,and then glazing and polishing.Two types of dedicated zirconia polishing burs(DFS,MEISINGER),universal porcelain polishing bur(CERMASER)with a combination of two polishing paste(ZENOSTAR polishing paste,diamond polishing paste)are selected.(2)Zirconia ceramic specimens were processed surface roughness and scanning electron microscopy surface topography.(3)The bacterial adherence was evaluated by the colony forming unit and optical density of Streptococcus mutans in the finished zirconia porcelain specimen.Results:(1)Surface roughness test results: different surface treatment of two zirconia ceramic specimen,the surface roughness difference was statistically significant(P= 0.001).There was no significant difference in the surface roughness between the two zirconia samples(P= 0.704).The surface roughness of the zirconia ceramic specimen was significantly improved(P= 0.001).There was no significant difference between the three groups,they are lower than the sintering group,the difference was statistically significant(P = 0.006,0.002,0.000).ZENOSTAR zirconia all porcelain specimen can be polished better than AIDITE zirconia ceramic specimen(P = 0.001).Among the three polished lasers,the best-type zirconia polished bur MEISINGER had the best polishing performance(P = 0.001).The polishing performance of universal porcelain polished bur(CERMASER)was the worst(P<0.001).There was no statistically significant difference in the polishing performance between the two pastes(P = 0.959).(2)Scanning electron microscopy observation: ZENOSTAR zirconia ceramic specimen sintering after the completion of the structure of dense,crystal structure of the boundary clear and uneven.AIDITE zirconia ceramic specimen sintered after the completion of the surface structure is dense but crystal structure.The border is not clear,not flat.The surface of the two zirconia ceramic test pieces became very rough,irregular,ridge and deep pits,and the surface after glazing treatment became smooth and smooth.Two zirconia ceramic test pieces after DFS,MEISINGER polished car polished surface becomes flat,with uniform scratches,which AIDITE zirconia ceramic specimen surface scratches deeper.Two zirconia ceramic burs after CERMASER polished car polished surface is still relatively rough,scratches are uneven,with ridges and pits.Two zirconia ceramic test pieces after ZENOSTAR polishing paste after the surface is more smooth,with the diamond polishing paste after the surface treatment scratches slightly shallow.ZENOSTAR zirconia ceramic specimen with AIDITE zirconia ceramic test pieces,the surface scratches lighter.(3)Streptococcus mutans CFU showed that the difference between the two zirconia porcelain samples was statistically significant(P = 0.012),and different surface treatments significantly affected the deformed chains of zirconia ceramic specimens(P = 0.001).There was no significant difference between the polishing group,the polishing group and the glaze group.(4)The results of OD of Streptococcus mutans showed thatthe results of optical density of Streptococcus mutans showed that there was no significant difference in the optical density of Streptococcus mutans after two surface treatment(P = 0.494).Different surface treatments change the optical density of Streptococcus mutans(P = 0.001)for zirconia ceramic specimens.No significant interaction was observed between the material and the surface treatment(P = 0.999).There was no significant difference in the optical density of Streptococcus mutans between the polishing group,the polishing group and the glaze group.There was no significant difference in the optical density of Streptococcus mutans between the sintered and blended zirconia samples(P = 0.327).Polishing group,polishing paste group,glaze group compared with the sintering group,zirconia ceramic specimen Streptococcus mutans decreased optical density.The density of Streptococcus mutans was higher than that of the sintered group(P = 0.001).Conclusion:(1)Sintered zirconia prostheses are recommended for routine dressing,regardless of the need for clinical occlusal adjusting,which can significantly reduce the surface roughness of zirconia prostheses and significantly reduce the amount of Streptococcus mutans.(2)It is recommended to use a dedicated zirconia polishing burs.The MEISINGER special zirconia polishing burs can significantly reduce the surface roughness of zirconia and significantly reduce the amount of Streptococcus mutans.It is not recommended to use universal porcelain polished burs.(3)The use of polishing paste does not affect the final polishing effect,does not affect the amount of Streptococcus mutans adhesion.