Mini-implants for Orthodontic Anchorage: Surface Analysis after Redrilling and Sterilization – An in vitro Study

Abstract

Objective: This study aimed to investigate, in vitro, possible alterations on mini-implants surface after retrieval and if the cleaning process and sterilization can predispose damages. Materials and methods:Two commercial mini-implants were tested for deformations after drilling and removing in artificial bone four times. Samples were analyzed by scanning electron microscopy, and surface alterations verified through thread and pitches deformation. To alterations caused by insertion/removal and the cleaning process and sterilization were verified in different procedures: Insertions and sterilization, only insertions, and only sterilization. Photomicrographs were analyzed in order to compare the surface characteristics. Head deformation was verified qualitatively. For a quantitative analysis, distances between threads were measured across the active part of the mini-implants. Results:No deformation was observed in both groups. The cleaning and sterilization processes did not provoke alteration in both groups. Nevertheless, the presence of synthetic bone was noted in some samples. The mean distances between implant threads were similar after all steps in all regions in both groups. Conclusion:The results suggest that the tested mini-implants can be retrieved without damage of its surface after four cycles of insertion, removal, and sterilization.

Ions release Evaluation and Changes in Mini-implant Orthodontic Surface

“…The images were obtained with secondary electron detector, increasing from 200× to 2000×, 20 kV, and 0.8 μA. 21…”

Surface characteristics and mechanical behavior of retrieved orthodontic microimplants

“…The aforementioned situations are all related with the reuse of microimplants, including immediate relocation and postponed relocation. However, it remains controversial whether the reuse of microimplants is sensible and feasible (Mattos et al, 2010;Chung et al, 2014;Estelita et al, 2014;Iijima et al, 2015;Noorollahian et al, 2015;Gross et al, 2016). In previous studies, some researchers described their recycling protocols and reported that their methods had no significant negative effects on mechanical strength (Estelita et al, 2014;Noorollahian et al, 2015;Gross et al, 2016), while others did not recommend the reuse of retrieved microimplants because of their altered surface characteristics and changed mechanical properties (Mattos et al, 2010;Chung et al, 2014).…”

A comparative surface evaluation of orthodontic mini-implants before and after en masse retraction—A SEM study

“…A thorough understanding of biomechanical principles involved in the application of micro-implants should be known, and the complete assessment of anchorage should be evaluated at the start of the treatment. [ 10 13 ]…”

“…Immediate loading in clinical practice could reduce osteointegration and thus leads to soft tissues not enveloping the mini-screw surfaces. [ 9 10 ] Manufactures usually supply information on outer diameter, length, and chemical composition. Depth, pitch, and lead angle of the thread and surface characteristics are rarely provided.…”