Comparison of Biomechanical Properties of Surface-Treated and Untreated Machined Orthodontic Mini-Implants: An In Vitro Study

Abstract

Background and Objectives: The use of mini-implants has become more popular, and there has been a heightened focus on factors that contribute to their success. The purpose of the study is to compare the effects of various surface treatment methods of mini-implants on their bone cutting capacity, insertion torque required, and fracture resistance when compared with the untreated machined mini-implants. Materials and Methods: The study included 4 groups. Each group consisted of 10 orthodontic mini-implants (OMIs). The first experimental group contains titanium oxide coated mini-implants, the second group contains grit-blasted implants with aluminum oxide, the third group consists of mini-implants coated with hydroxyapatite crystals, and the control group is formed by untreated machined mini-implants. Each group is evaluated for cutting efficiency, maximum insertion torque, and fracture resistance using a customized torque testing gauge. Results: The results showed that surface treating OMIs with hydroxyapatite particles increases the surface roughness, thereby enhancing their stability without decreasing the bone cutting ability compared with OMIs without surface treatment. Conclusion: Roughened surface of OMIs with hydroxyapatite particles exhibited maximum fracture resistance without decreased corresponding bone cutting efficiency.