人牙本质通透性的体外测定

The permeability of human dentin in vitro

目的:体外比较不同测试条件和不同部位人牙本质的通透性。方法:切取人离体下颌第三磨牙牙合侧近髓、中间及颊侧近髓、中间牙本质片,经酸蚀处理后,采用灌注法分别在不同液压、不同渗透液体条件下测定其通透值;并用金相显微镜观察各部位牙本质小管密度,分析通透值与牙本质小管密度间的相关性。结果:100 cm液压测定的通透值明显大于32 cm液压(P<0.05);稀释牛血清测得的通透值明显小于蒸馏水和生理盐水(P<0.05),蒸馏水与生理盐水相比无统计学差异(P>0.05);牙合侧牙本质通透值明显大于颊侧,近髓牙本质通透值明显大于中间(P<0.05);牙本质通透值与其小管密度呈显著正性相关(P<0.05)。结论:牙合侧牙本质通透性大于颊侧,牙本质通透性与其小管密度密切相关,实验结果对临床粘结剂的选择有一定指导意义。

AIM： To compare the permeability of different parts of dentin and in different conditions. METHORDS： Dentin discs from various parts of extracted human third molars were prepared and treated with 35% phosphate acid, then permeability of the discs was measured by perfusion method under different hydrostatic pressure and with different perfusion fluid. The correlation between the dentin permeability and dentinal tubular density was ana- lyzed. RESULTS ： The permeability of the dentin discs under the hydrostatic pressure of 100cm water column was sig- nificantly higher than that under 32cm（P 〈 0.05 ）. The permeability of the discs in diluted bovine serum was signifi- cantly lower than that in distilled water and saline （P 〈 0.05）. No significant difference was found between the perme- ability values in distilled water and saline（P 〉 0.05 ）. The permeability of the occlusal dentin was significantly higher than that of buccal dentin（ P 〈 0.05 ）. The permeability of the inner dentin was significantly higher than that of middle dentin（ P 〈0.05 ）. The permeability of the dentin was positively related to the dentin tubular density （P 〈 0.05 ）. CONCLUSION： The permeability of the occlusal dentin is higher than the buccal dentin. Dentin permeability is core- lated with the dentinal tubular density.