The Study Of Dental Unit Water Lines Contamination And Antibacterial Effect Of Nano-silver Disinfectant

Objective:1.To provide a scientific basis for the control of pollution by studying pollution status of dental unit water lines from three different types hospitals in our city.2.To study the efficacy and timeliness of aerobic bacteria disinfection in dental unit water lines water contamination by using nano-silver disinfectant,and to explore appropriate disinfection methods and dosage.Methods:1.Choose 10 dental unit from three types of hospitals including private dental clinics separately(A),community hospitals(B),general hospital(C),for each dental unit,collective the water from the the high-speed,mouthwash,teeth cleaning machine at the time of initial diagnosis and treatment before and after the whole day use water,put the samples in sterile collection tube,and coated plate count in 1hour.2.Four concentrations of nano silver solutions(0.25%,0.5%,1%,2%)and solid medium containing nano silver were used to treat water samples in the dental unit water lines,respectively,and the bacteriostatic effect of nano silver on 1 day,4 days,7 days,14 days and 28 days was observed.Results:Comparison of different hospital grades,the number of colonies: class B hospital > class C hospital > class A hospital;Before and after treatment,except that there was no statistically significant difference in the number of bacterial colonies before treatment in B hospital,C hospital,and C hospital before and after treatment of dental cleaning machine,the number of bacterial colonies in other groups was significantly higher than that after treatment,and most of them were more seriously polluted before a day of treatment than after treatment.;Compared with different parts,the number of colonies: tooth cleaning machine > high-speed mobile phone >mouthwash.The water pollution of mouthwash was generally lighter than that of dental cleaning machines and high-speed mobile phones in the three types of hospitals.2.The bacteriostatic effect of nano-silver in the liquid phase at all four concentrations was not good.The bacteriostatic rate of 1 day after disinfection was 20%,and a large number ofbacteria could be seen on 4 days,7 days,14 days and 28 days.There was no bacterial growth at 1 day,4 days,7 days and 14 days after disinfection of the four concentrations of solid nano-silver,and there was no difference between the concentrations.A small amount of bacterial growth was found after 28 days.Conclusion:The status of pollution for different parts of dental units from not the same though from several types of hospitals,and the effect of water disinfection during night is not satisfactory.2.The solid nano-silver has a strong antibacterial effect on the anaerobic bacteria in the dental unit water lines.