聚酰胺－胺诱导牙本质表面矿物沉积的体外实验

摘要

Objective:To evaluate the sealing ability of the 3.0th generation of polyamidoamine dendrimer(3.0 PAMAM)on hu-man dentinal tubules.Methods:1 6 extracted premolars were cut into 2 mm thick dentin slices to establish sensitive dentin model in vitro.Then 2 samples without any treatment were selected randomly into demineralized dentin group,and the remain 1 4 dentine pills were divided into 2 groups by the random number table(n=7).Samples in the experimental group were treated with 3.0 PAMAM, those in the control group were treated with deionized water.After having immersed in the artificial saliva for 2 and 4 weeks respec-tively,the dentin slices were examined by scanning electron microscope(SEM)and X-ray energy dispersive spectroscopy(EDS). Results:SEM showed that the minerals on the surfaces of the dentine disks in experimental group were formed gradually with the time,the dentinal tubules were blocked 4 weeks after treatment.The minerals on the sample surface in control group were less and the dentinal tubules remained open.EDS results showed that Ca/P(1 .49 ±0.1 6)of mineral deposition in the experimental group was higher than that in the control group (1 .1 8 ±0.20)(P<0.05).Conclusion:The 3.0th generation of PAMAMhas the occlu-ding ability by inducing remineralization on the dentine surface and it may be used in the treatment of dentin hypersensitivity.%目的：探讨3．0代聚酰胺－胺（3．0PAMAM）在牙本质表面诱导生成的矿化物封堵牙本质小管的效果。方法：选取16颗健康正畸牙，制备16个脱矿牙本质样本，按随机数字表法随机选择7个样本作为对照组，7个作为实验组，余2个样本不做任何处理作为脱矿牙本质组。对照组用去离子水处理，实验组用3．0 PAMAM处理之后将各组样本同时浸入人工唾液2、4周后，通过SEM观察每组牙本质小管的微观形貌，X射线能谱仪（EDS）检测牙本质表面沉积物的钙、磷元素含量，并采用两独立样本t检验分析比较4周后2组样本的Ca／P值。结果：SEM观察显示实验组牙本质样本矿化程度随矿化时间延长，表面矿化物逐渐形成，处理4周后完全覆盖所有的牙本质小管口。对照组样本表面矿化物较少，牙本质小管口仍然开放。EDS结果显示沉积物Ca／P值实验组（1．49±0．16）高于对照组（1．18±0．20）（P＜0．05）。结论：3．0代聚酰胺－胺对敏感牙本质有一定的生物矿化及封闭作用，在治疗牙本质敏感方面存在潜在价值。