不同方向剪切力作用下两种树脂粘结剂与人牙釉质的剪切粘结强度研究

目的：考察不同施力方向上树脂粘结剂与人牙釉质的剪切粘结强度。方法：使用树脂类粘结剂A（Clearfil SE BOND）和B（Prime＆Bond NT），将各自配套的复合树脂粘结在离体人牙釉质面上，当剪切力沿根尖、骀面、近中和远中方向作用时测量其剪切粘结强度。结果：粘结剂A和B与牙釉质的剪切粘结强度值显示，根尖方向[分别为（44．38±3．68）Pa和（45．50±2．88）Pa]〉近中方向[分别为（37．81±7．56）Pa和（40．15±2．59）Pa]和远中方向[分别为（35．71±3．34）Pa和（35．75±4．15）Pa]〉[牙合]面方向[分别为（29．19±3．75）Pa和（33．44±3．79）Pa]，近中方向和远中方向间差异无统计学意义（P〉0．05），根尖方向与[牙合]面方向间差异有统计学意义（P〈0．05）。结论：树脂粘结剂与人牙釉质剪切粘结强度的大小与剪切力作用的方向相关。

Directionality of shear bond strength of resin adhesives on human enamel

OBJECTIVE: To investigate the relationship between the shear bond strength of resin adhesion on the enamel of human teeth and loading direction. METHODS: Two kinds of dental resin adhesives [Group A (Clearfil SE BOND) and Group B (Prime&Bond NT)] were used to bond their responding resin composites to the enamel of human teeth respectively. The shear tests were performed from four directions: root apex direction, occlusion direction, mesial direction, and distal direction. RESULTS: The shear bond strength of the two resin adhesives on the enamel behaved in the same way, which was the root apex direction [(44.38 +/- 3.68) Pa and (45.50 +/- 2.88) Pa] > mesial direction [(37.81 +/- 7.56) Pa and (40.15 +/- 2.59) Pa] and distal direction [(35.71 +/- 3.34) Pa and (35.75 +/- 4.15) Pa] > occlusion direction [(29.19 +/- 3.75) Pa and (33.44 +/- 3.79) Pa], respectively. A significantly statistical difference in the shear bond strength values was found between the root apex direction and the occlusion direction (P < 0.05), and there was no statistical significant difference between the mesial and distal directions (P > 0.05). CONCLUSIONS: The shear bond strength between the human tooth enamel and the dental resin adhesives is related to the direction of the shearing force.