The Comparative Study On Both The Surface Roughness And The Adhesion Of Streptococcus Mutans On Both Zirconia Ceramic And Titanium Alloy

When dental restorative materials are put into mouth as a variant substance,some changes in microecological conditions as caries or periodontitis may take place in the mouth.Adherence and colonization of microbe on dental restorative materials are first and vital steps for further aggravation.The process of adhesion is complex and is affected by many factors,such as materials used,surface characters,a kind of bacteria,acquired pellicle and components of saliva.Purpose:This study is to measure the surface roughness of the samples after the respective surface finished and their ability of retention of Streptococcus mutans.In addition this study is to compare the difference of surface properties between two prosthodontic materials in order to provide the theory for clinical application.Methods:Twelve specimens of each material are fabricated according to the manufactures' directions and divided into five groups.Each sample group adopts respective clinically and commonly used surface treatment method grinding,polishing and glazing.Initial roughness measurements(Ra measured inμm)are made by the usage of a profilometer.Then the specimens are separately placed into liquid culture medium in which there are streptococcus mutans(ATCC 25175)and incubated in the condition of different vibrating speed for 1h under 37℃.Then,they are photographed and the adhered bacteria is counted,which is stained by acridine orange and is examined by fluorescence microscopy.All surface treatments are analyzed with SEM.Results:(1).There is no significantly difference of roughness values between group A and group B.The roughness of samples in group C are significantly rougher than that in group A and B.There is no significant difference of the cell adhesion on porcelain surface between they are glazed and polished,but more bacteria adhered on the porcelain surface in group C.SEM results show similar smooth surface for group A and group B,and polishing treatment has some fine cracks,and grinding treatment has some rough cracks(2).There is no significantly difference of roughness values between group A and group D.There is no significantly difference of the cell adhesion on the surface between group A and group D.SEM results show similar smooth surface for showed two groups(3).There is no significantly difference of roughness values between group B and group E.There is significant difference of the cell adhesion on the surface between group B and group E,more bacteria adhered on the surface in group E.polishing treatment of ceramic has some fine cracks,and polishing treatment of Titanium alloy has some leakage and introcession.Conclusion:(1).Porcelain surface polished treatment is clinically acceptable compared with its glazed.They all exhibit the least amount of bacteria adhesion.The more porcelain surface is rough,the more bacteria adhere on it.(2).Porcelain surface glazed treatment is clinically acceptable compared with titanium alloy glazed.They all exhibit the least amount of bacteria adhesion.(3).In clinics,porcelain surface polished treatment and titanium alloy polished treatment are commonly used.Porcelain surface polished treatment can obtain better surface properties than that of titanium alloy.