Antibacterial effect of 0.2% chlorhexidine and 1% chitosan mouthwash on bacteria during orthodontic miniscrew use

Objective: Inflammation is one of the most common complications observed when using orthodontic miniscrews. Chlorhexidine mouthwash can be used to prevent and reduce the degree of inflammation, but long-term use of this solution may lead to some side effects. This study sought to evaluate the peri-miniscrew antibacterial effect of 1% chitosan, a biomaterial with antibacterial properties, relative to 0.2% chlorhexidine mouthwash. Methods: A randomized, double-blind clinical trial was conducted at the Dental Teaching Hospital and Oral Biology Research Laboratory at the University of Indonesia from February to June 2019. Thirty subjects (25 females and five males) were randomly assigned to rinse with 1% chitosan (n=10), 0.2% chlorhexidine digluconate (n=10), and Aquadest (n=10) in addition to their usual oral hygiene procedure for 4 days. Peri-miniscrew clinical inflammation signs were recorded and peri-miniscrew plaque collected before and after 4 days of rinsing. The total bacterial and red-complex bacteria count in plaque samples were evaluated by a real-time polymerase chain reaction. Results: Chitosan and chlorhexidine showed antibacterial activity, reducing total bacterial count around orthodontic miniscrews (p<0.05). The antibacterial activity of chitosan on total bacteria was not significantly different from that of chlorhexidine (p≥0.05). Regarding the antibacterial activity of chitosan on red-complex bacteria, the best result seen was a 58% bacteria count reduction in Tannerella denticola. Conclusion: Chitosan has potential antibacterial activity and could be used in mouthwash to maintain peri-miniscrew hygiene.