evaluation of changes in streptococcus mutans colonies in microflora of the indian population with fixed orthodontics appliances

background: orthodontic therapy has oral ecological changes causing increased numbers of mutans streptococci in saliva and plaque. the purpose of this study was to estimate counts and colonization pattern of streptococcus mutans after application of fixed orthodontic appliances. materials and methods: plaque samples of randomly selected sixty patients were collected before placement of orthodontic appliances from buccal and labial aspects of the anterior teeth and four first molars and readings were recorded as t0. after placement of appliances (0.22 mbt preadjusted gemini), i.e., 2nd and 3rd month, the plaque samples were collected again from same site and readings were recorded as t1 and t2, respectively. counts of s. mutans in these patients were determined by using dm strips (orion diagnostic, espoo, finland). kruskal–wallis test and mann–whitney u‑test were used to find out significant differences between different time interval for dentocult score for s. mutans in orthodontic patients ( p < 0.001). results: prior to the treatment, 46 patients (76%) showed mild and 14 patients (24%) showed moderate colonization of s. mutans . after treatment, the severity of colonization increased showing fifty patients (84%) moderate and six patients (10%) showing severe colonization of s. mutans at t1, which further increased in severity at t2 with 54 patients (90%) showing severe colonization with s. mutans . conclusions: results showed that fixed orthodontic appliance increases colonization of s. mutans during orthodontic treatment. key words: toothbrushing, oral hygiene, streptococcus mutans