Effect of two cleaning methods on the sterilizing efficacy and dental handpiece wear

Objective To compare the sterilizing efficacy and dental handpiece wear of automatic hot cleaner and automatic cleaning-oiling maintainer cleaning methods.Methods Eighty new NSK handpieces were randomly divided into two groups,with 40 cases for each group.Group A were cleaned by hot cleaner and group B were cleaned by automatic cleaning-oiling maintainer.Each handpiece was cleaned,oiled,sterilized and used in the clinic for 200 times.The handpiece wear situation was recorded and eath18 handpieces from two groups were randomly taken to Beijing Centers for Diseases Control and prevention for sterilization inspection.Results During the experiment,20 of the 80 handpieces went out of order and 11 of them were reused after maintenance,among which nine were from group A and two were from group B.The difference between two groups were statistically significant(x2 =1.029,P ＜0.05).No bacteria was detected in 18 handpieces in group A,while one of the eighteen handpieces in group B was contaminated with fungus.There was no statistically significant difference between the two groups (x2 =5.165,P ＞ 0.05 ).Conclusions There was no significant difference in the sterilizing efficacy between two cleaning methods.The cleaning method of automatic hot cleaner can increase the incidence of insufficient oiling for its incomplete internal desiccation.Therefore,cleaning-oiling maintainer is a low-wear cleaning method to dental handpiece cleaning. Key words: Sterilization; Dental handpiece; Cleaning; Wear