Impact of Orthodontic Fixed Appliances on Type and Quantity of Certain Periodontal Microbial Pathogens

Objectives: The main objective of this study was to detect the correlation between several periodontal pathogens and periodontal inflammation parameters and fixed orthodontic appliances. Materials and Methods: Periodontally healthy subjects 32 (14 M, 18 F) with a mean age of 17.5 years (range: 14-28 years) attending the orthodontic clinic were recruited. Clinical periodontal parameters; plaque index (PI), bleeding on probing (BOP) and probing pocket depth (PPD) were measured and plaque samples were collected before bonding orthodontic appliances (T0) and 3 months later (T1). Real-time polymerase chain reaction (PCR) analysis was conducted on the collected samples and tested for Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), and Porphyromonas gingivalis (Pg). Results: Periodontal parameters increased significantly at T1. The correlation analysis demonstrated that PI and BOP were significantly correlated at T0 (P<0.01) and at T1 (P<0.001). However, PPD was significantly correlated with BOP only at T1 (P<0.01). Regarding the bacterial concentration results, Tf had the lowest mean concentration with 0.66 and 1.47 DNA copy/sample at baseline, and following 3 months, respectively. On the other hand, the highest count was for Pg with a mean of 3.02×104 and 106×106 DNA copy/sample at baseline, and following 3 months, respectively. Conclusions: Patients with fixed orthodontic appliances showed highest concentrations of periodontal pathogens which might confirm that orthodontic appliances contribute in the periodontal inflammation. Accordingly, oral-hygiene measures should be emphasized for fixed orthodontic patients.