Influence of different implant materials on the primary stability of orthodontic mini-implants

Abstract

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft(3) trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates(®) device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success.

Figure 1

(A) Titanium alloy mini‐implant (diameter, 2 mm; length, 12 mm). (B) Stainless steel mini‐implant (diameter, 2 mm; length, 12 mm). (C) Titanium alloy mini‐implant (diameter, 2 mm; length, 10 mm). (D) Stainless steel mini‐implant (diameter, 2 mm; length, 10 mm).

Figure 2

(A) The Implomates^®, resonance frequency analyzer used in the study. (B) Resonance frequency (kHz) of test mini‐implant detected using the Implomates^® device.