Aim: Infectious complication which is reduced by chlorhexidine application may contribute to immediate orthodontic miniscrew failure. This study was determined to assess the influence of this agent on miniscrew immediate failure rate.
Materials and Methods: The study sample consisted of 62 miniscrews inserted in 31 patients that their treatment plan consisted of placing one miniscrew on each side of their maxillary arch between first molar and second molar (2 screws for each patient). Fifteen patients were given a chlorhexidine regimen.
Results: In the first six weeks after miniscrew insertion and before their loading 13.33 % of miniscrews in chlorhexidine group failed but the failure rate in non-chlorhexidine group was 6.25 %. According to Fisher's exact test the difference in failure rate was not statistically significant. Also there was no significant relation of failure rate to any category of the measured insertion torques or placement side (left or right) of miniscrews.
Conclusion: Using chlorhexidine does not affect the miniscrew immediate failure rate. Also, insertion torque value and placement side (left or right side of the jaw) in the maxilla do not seem to have influence in miniscrew failure rate.