Effect Of Disinfection Methods For Silicone Elastomer On The Surface Properties And Initial Candidal Adhesion

[Objective] To study the surface properties after silicone elastomer materials is disinfected by different kinds of disinfection methods,ompared with the surface morphology,the surface roughness.the surface wettability.the surface free energy and the number of the fungus adhered to the surface.[Materials and methods] First:The silicone elastomer specimen were cleaned by altrasonic cleaner for4min.Then divided those specimen into4groups. Group A was the specimen disinfected by high temperature and pressure(134℃) for30min, group B was the specimen disinfected by2%Alkaline glutaraldehyde forl Oh, group C was the specimen disinfected by1%Acetic acid peroxide for30,groupD was the specimen disinfected by0.1%Chlorine dioxide for1h.respectively.This was called the first sterilization time.Then had done it again for the second,third,forth sterilization time. Silicone elastomer materials without disinfectant treatment served as the controls.Observed the surface morphology of specimen in the SEM.Second:The contact angles were measured through the Sessile drop method before and after treatment. The changes of the contact angles were evaluated.The surface roughness was measured though the surface roughness measuring instrument.Third:Taking the common C.albicans for research.C. albicans that adhered on the specimens for2h,8h,24h was observed in vitro assay by Plate count method.[Results] First:As the time went on specimen were disinfected by group A and group B treatment.the size of the aperture in the surface were increasing. The filler exposed more and show the tendency of reunion.The surface morphology of the silicone elastomer infected C and D were relatively small.Second:As the time went on,specimen were disinfected by group A and group B, the surface roughness was increasing, surface wettability and surface free energy were decreasing. The surface quality of the silicone elastomer infected C and D were relatively small.Third:There was AP under the condition of2h、8h、24h in each time of4kinds of sterilization.the number of the fungus that adhered on the specimen was not seen obviously change. When there was no AP,high temperature and pressure group and glutaraldehyde group as the treatment of the extension of time, Ra>0.458um.the number of the fungus that adhered on the specimen was increasing.[Conclusion]1.With prolonging the sterilization time,The surface quality of silicone rubber is greater influence. At the same sterilization time,the specimen is disinfected by high temperature and pressure and glutaraldehyde whose surface quality is significantly greater than disinfected by Acetic acid peroxide and Chlorine dioxide, the surface quality of silicone rubber for Glutaraldehyde treatment group(except the first sterilization time) is greater than high temperature and high pressure treatment group.2. With prolonging the sterilization time, the number of C. albicans that adhered on the surface of the specimen that is disinfected by high temperature and pressure and glutaraldehyde is greater than Acetic acid peroxide and Chlorine dioxide Without the condition of the AP.There is the AP under the condition of2h,8h,24h in each time of4kinds of sterilization,the number of fungus that adhered on the specimen is not seen obviously change.