Background and aim: Recurrent aphthous stomatitis is a relapsing disease with typical ulcers that involve the oral mucosa. The objective of this study was to determine the microbial flora and pH of mouth in patients during and between disease relapse.
Materials and Methods: Patients were selected by simple non-random sampling. Totally 28 patients were included in this study. After filling out a questionnarie, patients were referred to the laboratory and a sample from oral ulcer was obtained and cultured in both aerobic and anaerobic media. PH of mouth was measured by pH meter. Same process was repeated two weeks after remission.
Results: Considering non-group A Streptococci and gram positive bacteria, there were no changes in oral flora culture in aerobic environment in relapse and remission time. Staphylococcus aureus growth was seen in aerobic environment in 3(10.7%) patients in relapse and in 2 (7.1%) in remission which was not statistically significant. There were not considerable changes in group A Streptococci in remission and relapses and also in gram negative bacilli. But in anaerobic cultures there was considerable increase of non-group A Streptococcus in relapse and remission (71/4%, in relapse and 39.3% in remission, P<0.01). There were not specific changes in other bacteria. There was higher oral pH in 53.3% of patients, lower pH in 20% and no change in pH in 26.7% of patients during active phase of disease.
Conclusion:There is considerable increase in non-A Streptococcus and increasing oral pH in majority of patients with aphthous stomatitis in relapse time.