Th. C. Vizitiu 1, Ecaterina Ionescu 1
1 Faculty of Dental Medicine, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
Abstract
Orthodontic appliances, both fixed and removable, impede the maintenance of proper oral hygiene and result in plaque accumulation. Many studies report that changes in the dental flora occur after starting the orthodontic treatment. The aim of this study was to evaluate the changes of the oral microbial flora during the orthodontic treatment. Materials and Methods. 24 young patients, aged 7-16, who were going to start the orthodontic treatment, have been selected. Group I was formed by the 24 patients before wearing any orthodontic appliance (T0) and group II was represented by 15 patients from the initial group, 3 months after the beginning of the treatment (T1). Coronary and subgingival plaque was collected for isolation and identification of the bacterial species involved. For the isolation of the bacteria, growth mediums were used: Todd Hewitt broth, Columbia agar, Schaedler broth and agar. The serial dilution method was used to determine the concentration of the bacteria (CFU/sample) from the aerobic and anaerobic flora. Conventional methods were used for the identification of the species and the isolated strains that are involved in pathological processes have been preserved for further study using molecular methods (PCR-based). Results and conclusions. The concentration of the aerobic and anaerobic bacteria has increased during the first 3 months of orthodontic treatment. The lactobacilli were isolated in a smaller proportion in group II (80% vs. 87% before the treatment). The oral streptococci and anaerobic bacteria isolation percentage increased after the beginning of the treatment. For the bacteria involved in pathogenic processes, an increase of the isolation rate has been observed for the patients wearing an orthodontic appliance, from 8.3% to 13.3% for S. mutans and from 4.2% to 6.7% for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. These results are not statistically significant and they are preliminary. Both study groups will be extended; dental microflora will be investigated at longer intervals of wearing orthodontic appliances.