The korean journal of orthodontics (대한치과교정학회지)
- Volume 15 Issue 2
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- Pages.261-269
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- 1985
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- 2234-7518(pISSN)
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- 2005-372X(eISSN)
A STUDY ON TENSILE STRENGTH AND PHYSICAL ALTERATION OF THERMALLY RECYCLED METAL BRACKETS
열처리한 재생금속 bracket의 인장강도와 물리적 변화에 관한 연구
- Park, Chang-Gee (Department of Dentistry, Graduate School, Chosun University)
- 박창기 (조선대학교 대학원 치의학과)
- Published : 1985.09.01
Abstract
The purpose of this study was to measure and compare tensile strength for 3 types of new direct-bond brackets and the same brackets after recycling and to evaluate recycled brackets to determine the extent of physical alteration after recycling. Three types of new direct-bond brackets were bonded to recently extracted human premolar teeth and the tensile strength was measured by Universal Testing Machine. The brackets were recycled by thermal process and the tensile test was repeated. To determine the extent of physical alteration after recycling, the slot width and the hardness of metal brackets were measured and to analyze the microstructure of the brackets, photographs of the bracket microstructure were taken. Following results were obtained: 1. The tensile strength of recycled brackets was lower than that of new brackets, but there was no statistically significant difference. (p>0.05) 2. In the new and recycled brackets, the tensile strength of mini-mesh base bracket was statistically higher than that of conturlok base bracket,
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