1. Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study
- Author
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Emine Buğra, Emre Oflaz, Fatma Kübra Erbay Elibol, Metin Orhan, Teyfik Demir, TOBB ETU, Faculty of Engineering, Department of Mechanical Engineering, TOBB ETÜ, Mühendislik Fakültesi, Makine Mühendisliği Bölümü, and Demir, Teyfik
- Subjects
Materials science ,Bone density ,Open Bite ,Orthodontics ,Common method ,Bone and Bones ,03 medical and health sciences ,0302 clinical medicine ,Bone Density ,Cortical Bone ,Orthodontic Anchorage Procedures ,medicine ,Humans ,Dental Implants ,Open bite ,Anchorage ,Dominant factor ,030206 dentistry ,Pullout strength ,medicine.anatomical_structure ,Mini implants ,Loading rate ,Cortical bone ,030217 neurology & neurosurgery - Abstract
Introduction: Anchorage, which is defined as resistance against undesired tooth movements, is one of the most important factors in success of orthodontic treatment. In recent years, mini-implants have been used instead of uncomfortable headgears and Nance appliances. The pullout test is the most common method for measuring the anchorage capacity of mini-implants. The aim of this study was to investigate the effects of cortical bone thickness and cortical layer bone density on pullout strength of mini-implants. Methods: Mini-implants were placed in polyurethane foam blocks representing 3 different cortical thicknesses (1 mm, 2 mm, and 3 mm) and 3 different cortical bone densities (grade 40, grade 45, and grade 50). Pullout tests were performed with 5 mm/min loading rate. Load vs displacement values were recorded during the tests. Results: Comparing cortical thicknesses on the same bone densities, statistically significant differences were found between 1 mm, 2 mm, and 3 mm thicknesses. Likewise, comparing bone densities on the same cortical thicknesses, statistically significant differences were found among all groups. Spearman rank tests showed that both cortical thickness and cortical bone density are correlated with pullout strength (rs, 0.548; P