DISCUSSION
fracture, orthodontic
SECONDARY
Surface treatment with sandblasting and acid etching allows osteoblast migration and retention over the orthodontic mini-implant surface, facilitating osseointegration, which results in improved clinical stability of the implant.Primary stability is defined as the mechanical retention of the implant to the bone. It is an important factor determining the clinical success of an implant and is commonly assessed by measuring the maximum insertion torque. An optimum insertion torque reduces micromotion of the implant in the bone after insertion, which can affect primary mechanical stability. High insertion torque may result in stripping of the bone during insertion, which results in reduced holding strength of the implant and reduces the secondary stability of implants by 40%-50%.In this study, the mean maximum insertion torque for surface-treated mini-implants and non-surface-treated mini-implants was 17.9 ± 5.6 Ncm and 16.4 ± 9.0 Ncm, respectively (Although the insertion torque measured in this study was higher than the normally recommended (5-10 Ncm), the failure rate reported was comparable to that reported in previous studies.The removal torque is the rotational force applied for the removal of mini-implants. The maximum removal torque is the highest value of removal torque recorded during implant removal.In this study, the mean removal torque of surface-treated and non-surface-treated mini-implants was 8.1 ± 2.9 Ncm and 3.3 ± 1.9 Ncm, respectively (The removal torque is a parameter widely used for evaluating the osseointegration of implants. Osseointegration of orthodontic mini-implants may offer high stability during orthodontic treatment and the ability to withstand dynamic and rotational forces, and may allow more choices for the application of orthodontic force.The implications of osseointegration in implant removal after the completion of orthodontic treatment are relevant. A very high removal torque may damage the surrounding bone or fracture the mini-implant during removal.In this study, non-surface-treated mini-implants contributed with 71.4% of the failed implants, whereas surface-treated mini-implants contributed with 28.6% of the failed implants. Although the failure rate was lower for surface-treated mini-implants than for non-surface-treated mini-implants, the difference was not statistically significant. This may be attributed to the small sample size of this study (Extensive research has been conducted in the past, both with dental and orthodontic implants, concluding that increasing the roughness of implants promotes osseointegration.