Cytotoxic effects of titanium alloy orthodontic mini-screw implants: Clinical prospective study

Abstract

Objectives: to evaluate possible cytotoxic effects of titanium alloy (Ti alloy) orthodontic miniscrew implants on the surrounding oral mucosal cells. Materials and Methods: Thirty orthodontic mini-screw implants (MSIs) installed to serve as anchorage for maxillary canine retraction after maxillary first premolar extraction. Fifteen female orthodontic patients with mean age of 16.11±1.68 years were consented to participate in the study, which ran for four months. The orthodontic appliance consisted of direct-bonded Roth monocrystalline ceramic brackets, and teflon-coated preformed archwires. Clinical evaluation of MSIs and oral hygiene condition were evaluated throughout the study period. Percentage of oral mucosa cells' DNA fragmentation were analyzed before insertion of MSIs, after one week, one month, three months and four months of MSIs insertion with the Comet assay analysis. Results: ANOVA test showed statistically significant decrease in oral hygiene condition during the study period. Statistically insignificant difference was evident in DNA fragmentation index of the collected oral mucosal cell in different time intervals. Conclusions: Orthodontic titanium alloy MSIs were biocompatible and demonstrated no cytotoxic effects on oral mucosal cells.