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Li Z, Zhang K, Li R, Xu L, He L, Pang X, Lu J, Cao B, Zhang B. [Effect of orthodontic traction on the microstructure of dental enamel]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2020; 40:1165-1171. [PMID: 32895182 DOI: 10.12122/j.issn.1673-4254.2020.08.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the effect of orthodontic traction on the microstructure of dental enamel. METHODS Forty-eight isolated premolars were randomly divided into 6 groups (n=8), including Group A (blank control group), in which the teeth were bonded with the orthodontic brackets without any loading force; Groups B1, B2, and B3 where the teeth were bonded with the orthodontic brackets using clinical adhesives and loaded with 50 g force for 6 months, 200 g force for 6 months, and 200 g force for 1 month, respectively; and Groups C1 and C2, where the teeth were bonded with straight wire brackets using light curing bonding and chemical curing bonding techniques, respectively. All the teeth were embedded with non-decalcified epoxy resin. Scanning electron microscope (SEM), atomic force microscope (AFM), and energy spectrometer (EDS) were used to analyze interface morphology and elemental composition of the teeth sliced with a hard tissue microtome. RESULTS Compared with those in Group A, the teeth in the other 5 groups showed increased adhesive residue index with microcracks and void structures on the enamel surface under SEM; AFM revealed microcracks on the enamel surface with angles to the grinding direction. A larger loading force on the bracket resulted in more microcracks on the enamel interface. The interface roughness differed significantly between Groups A and C2, and the peak-to-valley distance differed significantly between Groups A, C, and C2. CONCLUSIONS Orthodontic traction can cause changes in the microstructure of normal dental enamel.
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Affiliation(s)
- Zhixin Li
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Kailiang Zhang
- School of Stomatology, Lanzhou University, Lanzhou 730000, China.,Department of Prosthodontics, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Ruiping Li
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Lingdan Xu
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Lulu He
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Xiaochan Pang
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Jiyuan Lu
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Baocheng Cao
- School of Stomatology, Lanzhou University, Lanzhou 730000, China.,Department of Orthodontics, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Baoping Zhang
- School of Stomatology, Lanzhou University, Lanzhou 730000, China.,Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China
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Nakamura K, Abe S, Minamikawa H, Yawaka Y. Calcium Charge and Release of Conventional Glass-Ionomer Cement Containing Nanoporous Silica. MATERIALS 2018; 11:ma11081295. [PMID: 30060441 PMCID: PMC6117706 DOI: 10.3390/ma11081295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 07/21/2018] [Accepted: 07/23/2018] [Indexed: 11/16/2022]
Abstract
The aim of this study was to evaluate calcium charge and release of conventional glass-ionomer cement (GIC) containing nanoporous silica (NPS). Experimental specimens were divided into two groups: the control (GIC containing no NPS) and GIC-NPS (GIC containing 10 wt % NPS). The specimens were immersed in calcium chloride solutions of 5 wt % calcium concentration for 24 h at 37 °C, whereupon the calcium ion release of the specimens was measured. The calcium ion release behavior of GIC-NPS after immersion in the calcium solution was significantly greater than that of the control. Scanning electron microscopy and electron-dispersive X-ray spectroscopy results indicated that calcium penetrated inside the GIC-NPS specimen, while the calcium was primarily localized on the surface of the control specimen. It was demonstrated that NPS markedly improved the calcium charge and release property of GIC.
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Affiliation(s)
- Koichi Nakamura
- Department of Dentistry for Children and Disabled Person, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586, Hokkaido, Japan.
| | - Shigeaki Abe
- Department of Biomaterials and Bioengineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586, Hokkaido, Japan.
| | - Hajime Minamikawa
- Department of Dentistry for Molecular Cell Pharmacology, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586, Hokkaido, Japan.
| | - Yasutaka Yawaka
- Department of Dentistry for Children and Disabled Person, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586, Hokkaido, Japan.
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