空气喷磨对乳牙树脂充填微拉伸强度的影响

目的：研究空气喷磨对乳牙树脂充填微拉伸强度的影响,为该技术的临床应用提供依据。方法24颗离体乳磨牙切除冠部釉质暴露牙本质后,随机分为2组,分别用50μm氧化铝微粒空气喷磨(空气喷磨组)和金刚砂车针预备(金刚砂车针组)。每组抽取2个样本牙,1个样本牙直接扫描电镜观察,另外1个进行酸蚀后行扫描电镜观察。余留样本牙复合树脂充填后制成试件,采用微拉伸技术,测试试件断裂时的最大应力。结果空气喷磨组的微拉伸强度为(24.470±3.194) Mpa,高于金刚砂车针组(22.294±2.268) Mpa,差异有统计学意义(P<0.05)。扫描电镜观察：涡轮机金刚砂车针预备后酸蚀的牙本质表面呈浅坑状形态,空气喷磨后酸蚀呈规则的蜂窝状。结论空气喷磨技术可提高乳牙复合树脂充填的微拉伸强度。

The influence of the air abrasion on the resin filling microtensile bond strength of deciduous tooth

Objective To investigate the influence of the air abrasion on the resin filling microtensile bond strength of deciduous tooth. Methods 24 primary molars were randomly divided into 2 groups. Crown enamel was removed to ex-pose dentin. Superficial occlusal dentin were prepared by air abrasion or high-speed dental bur. Two samples were select-ed from each group. One of them was directly observed by scanning electron microscope ( SEM) and the other was ob-served by SEM after etching. The rest of samples were restored with the composite resin. Microtensile test was used to ex-amine the microtensile bond strength. Results The microtensile bond strength of air abrasion group was ( 24. 470 ± 3. 194) Mpa, which was statistically higher than that of high-speed dental bur group ( 22. 294 ± 2. 268) Mpa ( P<0. 05) . The tooth prepared by air abrasion with etching showed the characteristic of "honeycomb" pattern in SEM micrograghs, while the tooth in the control group showed a shallow shape. Conclusion Air abrasion preparation can improve the mi-crotensile bond strength in dentin restorations with the composite resin.