Influence of Finishing Clear Aligner Marginal Termination Design on Subgingival Periodontal Microbiota During Orthodontic Treatment: A Prospective Longitudinal Split-Mouth Study

What this Trial Is About

Researchers are investigating whether the edge design of clear orthodontic aligners worn during the finishing phase affects the bacteria living in the groove between the tooth and gum (gingival sulcus). The study compares two designs: a supragingival edge that covers about 2 mm of gum tissue and a juxtagingival edge that follows the gumline exactly without covering gum tissue. The main question is whether the supragingival design leads to higher levels of bacteria associated with gum disease after 4 and 8 weeks of wear. Participants wear both aligner designs at the same time—one on the upper jaw and the other on the lower jaw—for 8 weeks. The aligners are made from the same material and differ only in their edge shape. The supragingival design partially encloses the gum groove entrance, potentially reducing saliva flow and oxygen, while the juxtagingival design leaves the gum groove more exposed. This split-mouth design allows participants to serve as their own control, improving comparison accuracy. Throughout the study, participants visit three times: at baseline, 4 weeks, and 8 weeks. During these visits, fluid samples from the gum groove are collected to measure levels of seven bacteria linked to gum disease using a real-time PCR test. Participants report their aligner wear time to ensure compliance. Researchers focus on the number of bacteria exceeding clinical thresholds in each jaw and analyze differences between the two aligner designs. The total participation involves wearing aligners for 8 weeks with periodic sample collection and monitoring.

Influence of Finishing Clear Aligner Marginal Termination Design on Subgingival Periodontal Microbiota During Orthodontic Treatment: A Split-Mouth Study.