TENSILE STRENGTH OF DIRECT-BONDING BRACKETS

Direct-bonding bracket 의 인장강도(引張?度)

As adhesive systems were improved, a great variety of bracket bases were available. The purpose of this study was to evaluate the adhesive porperties of 3 types of direct-bonding brackets by testing the tensile stremgth. 60 noncarious premolars extracted for orthodontic treatment were used. The tensile strength was tested by Tensilon/UTM-1-10000C after 24 hours from bonding. Following results were obtained; There was no difference between the tensile strength of foil-mesh base bracket and photoetched base bracket statisstically. However, the accurate test result of plastic bracket could not be obtained due to the distortion of bracket wing during testing. Of the failure in fail-mesh base bracket and photo-etched base bracket, the combination type of failure, where part of the adhesive remained on the tooth and part on the bracket was the most common type (50%, 50%), The second type of failure occured at the bracket-adhesive interface (30%, 35%) and the last type of failure occured at the adhesive-tooth interface (20%, 15%).

저자(著者)는 3가지 종류(種類)의 bracket을 교정(矯正)을 위(爲)해서 발치(拔齒)한 20개(個)씩의 소구치(小臼齒)에 접착(接着)하여 24시간(時問) 후(後)에 인장강도(引張?度)를 측정(測定)한 결과(結果) 다음과 같은 결론(結論)을 얻었다. foil-mesh base bracket과 photo-etched base bracket의 평균인장강도(平均引張强度)는 통계학적(統計學的)으로 유의(有意)한 차(差)가 없으며, plastic bracket은 인장강도(引張强度) 측정(測定) 시(時) wing의 변형(變形)에 의(依)해서 정확(正確)한 측정(測定) 결과(結果)를 얻을 수 없 었다. 접착제(接着劑)가 떨어진 양상(樣相)은 foil-mesh base bracket과 photo-etched base bracket에서 접착제(接着劑)가 치아(齒牙)와 bracket 에 부분적(部分的)으로 붙어서 떨어진 것이 각기(各其) 50%로 가장 많았고, 접착제(接着劑)가 치아(齒牙)에만 붙어서 떨어진 것 (30%, 35%), 접착제(接着劑)가 bracket에만 붙어서 떨어진 것 (20%, 15%) 순(順)으로 나타났다.