Effects of recycling on the biomechanical characteristics of retrieved orthodontic miniscrews.
10.4041/kjod.2017.47.4.238
- Author:
Soon Dong YUN
1
;
Sung Hwan CHOI
;
Jung Yul CHA
;
Hyung Seog YU
;
Kwang Mahn KIM
;
Jin KIM
;
Chung Ju HWANG
Author Information
1. Department of Orthodontics, The Institute of Cranio-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Korea. hwang@yuhs.ac
- Publication Type:Original Article
- Keywords:
Retrieved orthodontic miniscrew;
Recycling;
Surface characteristics;
Biomechanical characteristics
- MeSH:
Microscopy, Electron, Scanning;
Recycling*;
Spectrum Analysis;
Torque
- From:The Korean Journal of Orthodontics
2017;47(4):238-247
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: The aim of this study was to compare recycled and unused orthodontic miniscrews to determine the feasibility of reuse. The comparisons included both miniscrews with machined surfaces (MS), and those with etched surfaces (ES). METHODS: Retrieved MS and ES were further divided into three subgroups according to the assigned recycling procedure: group A, air-water spray; group B, mechanical cleaning; and group C, mechanical and chemical cleaning. Unused screws were used as controls. Scanning electron microscopy, energy-dispersive X-ray spectrometry, insertion time and maximum insertion torque measurements in artificial bone, and biological responses in the form of periotest values (PTV), bone–implant contact ratio (BIC), and bone volume ratio (BV) were assessed. RESULTS: Morphological changes after recycling mainly occurred at the screw tip, and the cortical bone penetration success rate of recycled screws was lower than that of unused screws. Retrieved ES needed more thorough cleaning than retrieved MS to produce a surface composition similar to that of unused screws. There were no significant differences in PTV or BIC between recycled and unused screws, while the BV of the former was significantly lower than that of the latter (p < 0.05). CONCLUSIONS: These results indicate that reuse of recycled orthodontic miniscrews may not be feasible from the biomechanical aspect.
