Orthodontic appliances did not increase risk of dental caries and periodontal disease under preventive protocol.

Objectives: To assess periodontal parameters and microbial species levels after orthodontic appliance placement in patients who received oral hygiene instructions and who were monitored and motivated throughout the study.
Materials and Methods: The Periodontal Index was recorded and saliva collection was performed before (T0) and 30 (T1), 60 (T2), and 90 (T3) days after orthodontic appliance placement in 15 patients (mean age 17.53 ± 8.0 years). Analysis was carried out using checkerboard DNA-DNA hybridization. Nonparametric statistical analysis was performed.
Results: The Periodontal Index did not change. The total amount of the purple and red complexes and Candida species showed a significant decrease from T2. The green, yellow, and orange complex showed a significant decrease at T3. The specific species analysis showed that Prevotella nigrescens, Pseudomonas putida, Fusobacterium periodonticum, Pseudomonas aeruginosa, Peptostreptococcus anaerobius, and Tanerella forsythia showed high incidence before bonding, and their levels decreased at T2 and T3. Only Porphyromonas gingivalis showed increased levels at T2 and displayed the highest level at T3. The Streptococcus group decreased their levels from T2 onward.
Conclusions: A dynamic change in microbial levels was identified. The decrease in the levels of complexes present was only possible due to the mechanical method of oral hygiene implemented in this sample.