The purpose of the labor is determinate the factors thatb lead to the prevalence of caries and oral hygiene index OHI, the buffering capacity of saliva (ph) and caries prevalence. Were included respondents aged 12 years, students from elementary schools in the city of Stip (311) and their peers in rural areas near Stip.(104) For all students are made following research Determination of the frequency of dental caries; Determination the average caries index (KIP); Determination the general caries frewuency (KIO); Registration of the index of oral hygiene; Determination of buffering capacity of saliva using DENTOBUF- test ( vivadent, Schaan, Lihtenstein ) Assesment of the buffering capacity of saliva we get this results- 0 = Ph > 6 normal ( good buffer capacity of saliva ) blue color, 1 PH = 4.5-5.5- Trim ( midly acidic buffer capacity of saliva ) green color2= pH < 4.0 low ( acidic buffer capacity of saliva ) yellow color. The results indicate that at the respondents from Stip Kepwas 6.32 and for the environment 7, 22. Statistical difference on values for OHI index between the two groups of respondents indicating high statistical significance (p< 0.01). Statistical differences on pH values of saliva between the two groups of respondents indicating high statistical significance (p<0.01). The conclusion is that the data resived from this study will help in getting a realistic picture of dental health and risk factors of a particular territory andit is possible toa really help in implementation of appropriate measures. Key words: buffering capacity, caries prevalence
