Comparison of Microbial Colonization and Periodontal Status Between Conventional, Self Ligating and Clear Aligner Therapy. A Randomized Controlled Clinical Trial

Objectives: The purpose of this study was to evaluate the microbial colonization and periodontal status between conventional, self ligating and clear aligner system.
Methods: 60 non extraction orthodontic patients were randomly assigned to three groups; Group 1(G1) clear aligners (Invisalign), Group 2 (G2) self-ligating brackets and Group 3 (G3) conventional preadjusted edgewise brackets (PEA). The facial surface of maxillary lateral incisor and second premolar were used as target teeth for the anterior and posterior segments of the dental arch respectively. For microbial counts, plaque specimens were collected and serial dilution was performed. Tripticase soy agar plates were used for total bacterial evaluation and mitis salivarius bacitracin agar plates for strep. mutans respectively. The plates were incubated for 36 hours at 37°C. Periodontal health was measured using the gingival index (GI), plaque index (PI) and papillary bleeding index (PBI). Data collection was done at beginning of treatment (T0) and after 9 months of orthodontic treatment (T1). Statistical analyses were performed using dependent analysis of variance (ANOVA) with bonferroni post hoc analysis. The statistical significance was set at P<0.05
Results: All three groups were similar at the beginning of treatment. At the end of 9 months no significant differences were observed for total bacterial and strep. mutans counts in either the premolar or lateral incisor region between G1 and G2. However significant differences were observed for total bacterial count in the premolar region between G1 & G3, and G2 & G3. In terms of periodontal health G1 showed significantly lower gingival architecture scores compared to G2 and G3. No significant differences were observed for the plaque scores or bleeding patterns amongst either group.
Conclusions: Both clear aligner therapy and self-ligating brackets were superior to conventional appliances for microbial counts. However no significant difference was observed between clear aligners and self-ligating brackets.