Oral and throat microbiological changes after the orthodontic debonding

As already known, orthodontic treatment represents a factor of plaque retention, promoting an increase of bacterial growth in the oral cavity. Nevertheless, after the orthodontic debonidng an alteration of the previous microbiological status may occurs. The present study was designed to assess the variations among six bacterial species within the oral cavity and the status of oral health after the orthodontic debonding. At the end of the fixed orthodontic treatment, 30 patients were divided into three groups based on the type of retention: I - 10 patients were treated with upper and lower fixed retention devices, II - 10 with upper and lower removable retention devices and III - 10 with lower fixed and upper removable retention devices. To assess the alterations of oral microbiota after the orthodontic debonding, two salivary swabs were collected for each individual: the first immediately after debonding (T0) and the other one 6 weeks later (T1). Six species, the most correlated with the development of caries and periodontal disease, were selected for the microbiological analysis with Real-time PCR: Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella for-sythia, Treponema denticola and Fusobacterium nucleatum. Furthermore, in order to correlate the microbiological outcomes with the clinical condition, the oral health indexes at T0 and T1 were assessed for all patients. Six weeks after debonding, the salivary levels of the bacteria investigated tend to decrease and the values of the oral health indexes tend to improve with all types of treatment considered (p<.05). Salivary bacteria levels and oral health are similarly influenced by fixed and/or removable orthodontic retentions.