Assessment of the periodontal health status in patients undergoing orthodontic treatment with fixed or removable appliances : a microbiological and preliminary clinical study

Objectives: The use of removable orthodontic appliances minimizes the negative effects on periodontal health allowing patients to carry out oral hygiene without obstacles. The aim of this preliminary study was to evaluate microbiological and clinical changes presented during the first three months of orthodontic therapy in adults with fixed appliances and Invisalign® System (Align Technology, Santa Clara, California). Materials and Methods: Plaque Index (PI), Probing Depth (PD), Bleeding on probing (BOP), Compliance to oral hygiene and subgingival microbial samples were assessed in 30 patients. Samples were analyzed by real time PCR to detect periodontal pathogens and microbial biofilm mass. A statistical comparison was made over time and amongst the three groups, using Chi-square X2, Odds Ratios (OR), Regression analysis (DOE) and ANOVA. Results: After 30 and 90 days of treatment there was only one sample with periodontopathic anaerobes found in a patient treated using fixed orthodontic appliances. Direct influence of orthodontic treatment on compliance and less subgingival biofilm mass were found with Invisalign® patients who increased the time dedicated to oral hygiene. A decrease on PD (p=0,002) and BOP (p<0,001) was detected in the Invisalign® group after 90 days of treatment. Conclusions: In this preliminary study, fixed and removable appliances did not increase the risk for periodontal disease in patients undergoing orthodontic therapy. However, the removable Invisalign® appliances may facilitate oral hygiene procedures, maintaining a lower level of microbial biofilm mass, even with poor oral hygiene compliance, minimizing the negative effects on gingival inflammation.