effect of fixed orthodontic treatment on salivary flow, ph and microbial count

objectives : the present study was designed to evaluate the changes in saliva properties and oral microbial flora in patients undergoing fixed orthodontic treatment. materials and methods: two important saliva properties namely the salivary flow rate and ph as well as oral microbial flora were assessed in 30 orthodontic patients before starting fixed orthodontic treatment and after six, 12 and 18 weeks of treatment. selective media, sabouraud dextrose agar, mitis salivarius agar and rogosa agar were used for isolation of candida albicans, streptococcus mutans and lactobacillus acidophilus, respectively. statistical analysis was performed using friedman and dunn’s tests. p< 0.05 was considered statistically significant. results: after six, 12 and 18 weeks of commencing fixed orthodontic treatment, the total colony counts of candida albicans, streptococcus mutans and lactobacillus acidophilus showed a significant increase. the saliva ph decreased during the orthodontic treatment (p< 0.05) while the salivary flow did not change significantly.  conclusions: fixed orthodontic treatment causes major changes in the saliva properties. the changes in oral microflora and saliva properties show the importance of caries preventive measures during orthodontic treatment.