空气喷磨对乳牙树脂充填微渗漏的影响

Microleakage of composite resin restorations in primary molars after bur or air abrasion preparation

目的:体外评价空气喷磨备洞与常规车针备洞对乳牙树脂充填微渗漏的影响。方法:对照组(Ⅰ,n=12)人离体乳磨牙常规备洞,其余组分别用27μm(Ⅱ,n=12)和50μm(Ⅲ,n=12)氧化铝微粒空气喷磨备洞。每组抽取2颗样本,其中1颗牙齿进行酸蚀,2颗样本行扫描电镜对比观察。余牙树脂充填、热循环处理后亚甲基蓝溶液染色。结果:27μm氧化铝微粒空气喷磨与常规车针备洞比较无显著差别(P>0.05)。50μm氧化铝颗粒空气喷磨较常规备洞能显著减少乳牙树脂充填的微渗漏(P<0.05)。但50μm与27μm组间无显著差别(P>0.05)。扫描电镜观察:与单纯空气喷磨或常规车针备洞者比较,空气喷磨后酸蚀,牙齿表面形态呈规则的蜂窝状。结论:50μm氧化铝颗粒空气喷磨可显著减少乳牙树脂充填的微渗漏。

Objective： To investigate microleakage in class Ⅰ cavities prepared by air abrasion or high-speed dental bur in primary molars and restored with composite resin. Methods： Thirty primary molars were divided into 3 groups. Group Ⅰ（n = 12, control） ： prepared by high-speed; group Ⅱ（ n = 12） ： prepared by air abrasion, using 27 μm aluminum oxide particles; group Ⅲ（ n = 12） ： prepared by air abrasion, using 50 μm aluminum oxide particles, Two primary molars of each group, which one of them was etching, were observed by SEM. Preparations were placed with composite resin. All the primary molars in each group were thermocycled and dye penetration was evaluated in order scale. Results： No significant differences existed between groups Ⅰ and group Ⅱ（ P 〉 0.05 ）but a statistical difference between groups Ⅰ and groups Ⅲ （ P 〈 0.05 ）. The tooth preparated by air abrasion with etching showed characteristic ＂honeycomb＂ pattern in SEM-micrograghs. Conclusion： Air abrasion preparation influences microleakage in class Ⅰ restorations with the composite resin.