(A) prospective, split-mouth, clinical study of orthodontic titanium miniscrews with machined and acid-etched surfaces

Abstract

The aim of this study was to determine whether the success rate and primary stability of surface-treated miniscrews differed significantly from those of non-treated miniscrews. Patients who required one or more miniscrews for the same reason in each quadrant were recruited into a single-blinded, split-mouth, randomized, controlled trial with a 1:1 allocation ratio. Self-drilling miniscrews with two surface types were used; with no surface treatment and with an acid-etched surface treatment. The cumulative success rate and primary stability of each type of miniscrew was examined, and factors potentially affecting the success and failure of miniscrews were investigated. Forty patients were included in the study, with a total of 98 orthodontic miniscrews. 1. The overall success rate was 88.8 %, and the respective success rates for acid-etched and machined surface miniscrews were 91.8 % and 85.7 %. 2. The respective mean insertion torques were 13.62 ± 5.95 N•cm for acid-etched miniscrews and 13.38 ± 4 N•cm for machined surface miniscrews. Periotest values measured immediately after insertion were -0.50 ± 2.77 for acid-etched miniscrews and -0.28 ± 3.36 for machined surface miniscrews. There were no statistically significant differences between the two types of miniscrews 3. There was no significant difference in the mean insertion torques and periotest values according to surface treatment and jaw. 4. In the analysis of risk factors that affect the stability of orthodontic miniscrews, the success rate of miniscrews was low in cases of distalization and open bite group, which was statistically significant. Neither the success rate nor the primary stability of acid-etched surface miniscrews and machined surface miniscrews differed significantly. There is a high possibility that miniscrews will fall out in patients who have an open bite or require total distalization.