Mechanical Properties of Mini-Implants Used in Extra-Radicular Anchorage

• Published in: Pesquisa brasileira em odontopediatria e clínica integrada Vol. 23
• Main Authors: Lopes, Gabriela Barros, Pithon, Matheus Melo, Mordente, Carolina Morsani, Nojima, Lincoln Issamu, Horta, Martinho Campolina Rebello, Oliveira, Dauro Douglas, Soares, Rodrigo Vilamarim
• Format: Journal Article
• Language: English
• Published: Associação de Apoio à Pesquisa em Saúde Bucal 01.01.2023; Association of Support to Oral Health Research (APESB)
• Subjects: DENTISTRY, ORAL SURGERY & MEDICINE; Orthodontic Anchorage Procedures; Orthodontics; Stainless Steel; Titanium; Titanium; Orthodontic Anchorage Procedures; Stainless Steel; Orthodontics
• ISSN: 1519-0501; 1983-4632; 1983-4632
• DOI: 10.1590/pboci.2023.044

ABSTRACT Objective: To evaluate the mechanical properties of mini-implants (MIs) manufactured from stainless steel and compare them with conventional titanium-aluminum-vanadium alloy MIs. Material and Methods: The following groups were formed: G1 (n=24), 8×1.5 mm steel MIs; G2 (n=24), 12×2.0 mm steel MIs; and G3 (n=24), 10×1.5 mm titanium MIs. The 72 MIs were inserted in the infra zygomatic crest region of the maxilla and retromolar trigone in the jaw of 10 pigs. Pull-out, insertion torque, fracture and percussion tests were performed in order to measure the tensile strength, primary stability and fracture strength of MIs. A digital torque gauge was used to measure insertion and fracture torque, a universal mechanical testing machine was used for pull-out testing and a periotest device was used to measure the micromovement of MIs. For morphological and MI component evaluation, scanning electron microscopy (SEM) was performed. D'Agostino & Pearson, Kruskal-Wallis, and Dunn post-hoc and normality tests were used. Results: G2 insertion and fracture torques were significantly higher than G1 and G3 insertion and fracture torques (p<0.05). The pull-out and percussion tests presented similar values among the groups. SEM revealed that the fracture point was predominantly on the fourth thread for steel MIs (G1 and G2) and on the seventh thread for titanium-aluminum-vanadium MIs (G3). Conclusion: The mechanical properties of stainless steel MIs are superior to those of titanium-aluminum-vanadium alloy MIs.