The effects of different pilot-drilling methods on the mechanical stability of a mini-implant system at placement and removal: a preliminary study

Abstract

Objective: To investigate the effects of different pilot-drilling methods on the biomechanical stability of self-tapping mini-implant systems at the time of placement in and removal from artificial bone blocks. Methods: Two types of artificial bone blocks (2-mm and 4-mm, 102-pounds per cubic foot [102-PCF] polyurethane foam layered over 100-mm, 40-PCF polyurethane foam) were custom-fabricated. Eight mini-implants were placed using the conventional motor-driven pilot-drilling method and another 8 mini-implants were placed using a novel manual pilot-drilling method (using a manual drill) within each of the 2-mm and 4-mm layered blocks. The maximum torque values at insertion and removal of the mini-implants were measured, and the total energy was calculated. The data were statistically analyzed using linear regression analysis. Results: The maximum insertion torque was similar regardless of block thickness or pilot-drilling method. Regardless of the pilot-drilling method, the maximum removal torque for the 4-mm block was statistically higher than that for the 2-mm block. For a given block, the total energy at both insertion and removal of the mini-implant for the manual pilot-drilling method were statistically higher than those for the motor-driven pilot-drilling method. Further, the total energies at removal for the 2-mm block was higher than that for the 4-mm block, but the energies at insertion were not influenced by the type of bone blocks. Conclusions: During the insertion and removal of mini-implants in artificial bone blocks, the effect of the manual pilot-drilling method on energy usage was similar to that of the conventional, motor-driven pilot-drilling method.

Insertion torque and orthodontic mini-implants: A systematic review of the artificial bone literature

“…46,53 No differences in MIT levels were measured when pilot holes were prepared with either motor or hand-driven drills. 49…”

“…The stability of the connection of different cortical bone materials to polyurethane cancellous bone could also affect outcomes and could explain conflicting associations between MIT values and increasing cortical bone thickness. 13,14,49,54…”

“…A total of 23 articles fulfilled the eligibility criteria (Table 1). 13,14,16,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] Five of these articles were either complete or partial copies of original articles, and another three articles were suspect of duplicate publication because they appeared almost identical (Table 1). To control publication bias, multiple publications were counted as one study, and references of duplicate articles were only listed in the tables and not in the text of this article.…”

Effects of predrilling on the osseointegration potential of mini-implants

“…However, it should be noted that this method can significantly vary depending on the clinical environment (visibility and bone quality). 29 Hand drilling of the pilot hole is likely to be more easily accepted by clinicians and patients than handpiece drilling. Further study is required considering the differences between results for this animal study and a human clinical application.…”

Evaluation of Stability of Surface-Treated Mini-Implants in Diabetic Rabbits

“…The mini-implants were 1.8 mm in diameter and 8.5 mm in length. They were two-component system composed of screw and head portion (threaded portion 6.5 mm) (Cimplant Co., Seoul, Republic of Korea) [ 22 ]. The mini-implants were self-tapping and dull-pitched modified cylinder type and they were the same for both diabetic and control groups except for the surface treatment of one group.…”