Detection Of Mutans Streptococci (MS) From Saliva And Survey Of The MS Distribution Of Natural Population In Lanzhou

Objective:To investigate the oral Mutans Streptococci (MS) distribution situation from the habitants in Lanzhou and to provide basic data for the oral health and dental caries prevention. Methods:942cases saliva samples were collected using rinsing method from the permanent residents in urban and rural areas of Lanzhou City. They were grouped according to caries, age, gender, living location (urban and rural). MS were cultured by Murashige&Skoog medium (MS) and Dentocult SM, and checked with the microscopic observation. The MS-positive rates in various groups were analysed statistically. Results:The MS-positive rate in all samples was74.63%(703/942) and the MS-positive rate in male [80.36%(401/499)] is significantly higher than that in female [67.44%(292/433)]; In caries group, MS-positive rate is98.49%(456/463), while51.56%(247/479) in decay-free group (P<0.01); Rural group79.37%(350/441), while urban group71.66%(359/501)(P<0.05);89.32%(209/234) in35-44age group is highest than18-34,45-64and65-75age group (P<0.05). Conclusion:The MS-positive rate detection in oral cavity is closely relative to severity of dental caries; The male group is higher than female group; The incidence of dental caries and MS-positive detection rate is higher than other groups for the rural population, male and middle-age group (35-44years). These people need build better oral health behavior which is helpful for early diagnosis, early prevention and early treatment of dental caries.