Shear bond strength and debonding failure mode of ceramic brackets according to the surface treatment of porcelain

도재 표면 처리가 따른 세라믹 브라켓의 전단 접착 강도 및 탈락 양상

The purpose of this study was to evaluate the shear bond strength and failure mode of ceramic brackets according to the surface treatment of porcelain. Sixty Porcelain samples were randomly divided into six groups of ten samples. Then they were treated as follows: Group 1(silane only), Group 2(etching+silane), Group 3(stone+silane), Group 4(sandblasting+silane), Group 5(stone +etching+silane), Group 6(sandblasting+etching+silane) After surface treatment of porcelain, sixty Transcend 6000 brackets were bonded to the prepared porcelain surface and they were stored in $37^{\circ}C$ saline for 24 hours. An Instron universal testing machine was used to test the shear bond strength of ceramic brackets to porcelain. After debonding, bases of ceramic brackets and porcelain surfaces were examined under scanning electron microscope(SEM) to determine failure mode. Statistical analysis of the data was carried out with one-way ANOVA and Duncan's multiple range test. The results were as follows : 1. The shear bond strength of surface-treated groups 2 to 6 was higher than that of only silane-treated group 1, and there was statistical significance. (P<0.05) 2. There was no significant difference among the groups 3 to 6. (P>0.05) 3. The shear bond strength of etching-surface treated group 2 was significantly lower than those of sandblasting-surface treated group 4, complex surface treated group 5 and group 6. 4. According to the scanning electromicroscopic images, the surface roughness of sandblasting-surface treated group 4 was less than those of the group 5 and 6, but there was no significant difference in the shear bond strength. (P>0.05) As a conclusion we can have a clinically adequate bond strength when an application of silane is done after the treatment of porcelain surface with more than one way to bond ceramic bracket on the porcelain. Also, it is considered that the sandblasting and application of silane is effective for the simplication and convenience of the treatment.

도재의 표면처리가 세라믹 브라켓의 전단 접착강도에 미치는 영향과 브라켓 탈락 양상을 알아보기 위해 60개의 ceradent 도재 시편을 glazing 후 군당 10개씩 여섯 군으로 다음과 같이 분류하였다: 1군(silane), 2군(etching+silane), 3군(stone+silane), 4군(sandblasting+silane), 5군(stone+etching+silane), 6군(sandblasting+etching+silane) 통상적인 방법으로 세라믹 브라켓을 접착한 후 전단 접착강도를 측정하고 탈락양상을 육안 및 주사전자현미경으로 관찰하여 다음과 같주 결론을 얻었다. 1. 표면처리 후 silane을 도포한 2군부터 6군은 silane만을 도포한 1군에 비해 유의성 있는 전단 접착강도의 증가를 보였다(P<0.05). 2. 한 가지 방법 이상으로 표면처리한 3군부터 6군은 서로 유의한 차이를 보이지 않았다(P>0.05). 3. etching 표면 처리한 2군은 sandblasting 표면 처리한 4군과 복합 표면 처리한 5,6 군에 비해 전단 접착 강도가 낮았다. (p<0.05) 4. sandblasting 표면 처리한 4군은 주사 전자 현미경 소견상 복합 처리한 5,6군보다 감소된 요철 정도를 보였으나 전단접착 강도 측정 결과 유의한 차이를 보이지 않았다. (p>0.05) 이상의 결론을 종합해볼 때 도재에 세라믹 브라켓을 접착하기 위해서는 한가지 이상의 방법에 의한 도재의 표면처리 후 silane을 도포해야 임상적으로 적절한 접착강도를 얻을 수 있으며, 술식의 간편성을 고려할 때 sandblasting 후 silane 처리를 하는 것이 효율적일 것으로 사료된다.