Chitosan gel prevents the growth of , and in mini-implant during orthodontic treatment.

Aims: We evaluated the effect of chitosan gel on total oral bacteria, , , and , during orthodontic treatment with mini-implants.

Material And Methods: Thirty subjects with 52 orthodontic mini-implants were divided into three groups: one group was treated with chitosan gel, the other group with chlorhexidine gel, and the control group with placebo. The plaque of the orthodontic -mini-implant area was collected before and after gel treatment. The total oral bacteria and bacteria of , , and were determined with reverse transcription-quantitative PCR.

Results: Thirty-four orthodontic mini-implants (65.38%) appeared as healthy and showed no clinical signs of inflammation. The total number of bacteria was reduced after chitosan gel application. The highest decrease in the proportion of was observed in the chlorhexidine gel application group, which showed a value of 70.86%, whereas the chitosan gel application showed a reduction of only 26.59%, and the control gel application showed the lowest reduction effect of only 2.55%. The difference in the reduction between gel application groups was significant (P < 0.05) for and .

Conclusion: The gel containing chitosan reduced the levels of total oral bacteria and bacteria.