光学相干断层成像检测牙釉质表层脱矿与再矿化的实验研究

Experimental study on demineralization and remineralization of enamel surface using optical coherence tomography

目的利用光学相干断层成像技术(OCT)观察不同制剂对年轻恒牙釉脱矿和再矿化效果的影响。方法 将正畸拔除的年轻恒前磨牙制成60个釉质块,随机均分为4组。每天进行如下处理:A组蒸馏水湿敷30min;B组含氟牙膏湿敷30min;C组护牙素湿敷30min;D组多乐氟湿敷30min,置于脱矿液1.5h,最后置于人工唾液中22h。每个步骤间用去离子水冲洗实验样品。实验周期重复30天。在处理前和第 7、15、30天,使用扫频光源OCT完成对样本的扫描和成像,同时使用显微硬度计测量各样本表面的显微硬度。结果 釉质脱矿深度:7天后,A组与其他各组相互比较,差异有统计学意义( P <0.05),B、C、D组组间比较差异无统计学意义( P >0.05)。30天后,C组和D组比较,差异无统计学意义( P >0.05),其余各组之间两两比较,差异均有统计学意义( P <0.05)。显微硬度测量:30天后,各处理组较处理前显微硬度值降低,A组显微硬度值最低,C组与D组显微硬度值高于B组,且差异有统计学意义( P <0.05)。C组和D组间釉质块显微硬度值差异无统计学意义( P >0.05)。结论 OCT可以较准确的显示釉质脱矿部位,在早期龋的诊断方面具有临床意义。护牙素和多乐氟均能有效的抑制牙釉质表面脱矿。

Objective To investigate the effect of different preparations on demineralization and remineralization of young permanent teeth by optical coherence tomography (OCT). Methods A total of 60 enamel blocks were prepared from young permanent premolars and randomly divided into 4 groups. The surface of each sample was applied with the following materials, group A (distilled water),group B(fluoride-containing toothpaste),group C(tooth mousse),group D (Duraphat), then put into demineralization solution for 1.5h(37℃), and finally into artificial saliva for 22h(37℃).The experiment cycle was repeated for 30 days. The scanning and imaging of the samples were completed before treatment and 7, 15 and 30 days after treatment, and the micro hardness of each sample surface was measured by micro hardness tester. Results There was significant difference in the demineralization depth of enamel after 7 days between group A and other groups( P <0.05),but the difference was not significant among group B,C and D( P >0.05).There was no significant difference in the demineralization depth of enamel after 30 days between group C and group D ( P >0.05). Micro hardness value of group A was the lowest. The micro hardness value of group C and group D was higher than that of group B ( P <0.05).There was no significant difference in micro hardness value between group C and group D ( P >0.05). Conclusion OCT can accurately show the demineralization site of enamel. Both GC tooth mousse and Duraphat can effectively inhibit enamel surface demineralization.