Portland cement修复磨牙髓室底穿孔的实验研究

目的 评估波特兰水门汀(Portland cement,PC)直接修复磨牙髓室底穿孔的效果,并与无机三氧化聚合物(mineral trioxide aggregate,MTA)作比较.方法 选取人新鲜拔除的恒磨牙53颗,按随机数字表法分为PC、MTA2个实验组(n=24)和1个对照组(n=5).实验组在髓室底中央制备直径2 mm的穿孔模型,分别用PC和MTA修复穿孔.对照组只开髓不制备穿孔模型.利用体视显微镜观察修复后样本的根分叉形态.扫描电子显微镜(SEM)观察材料和牙体组织的结合界面,并测量结合界面间隙宽度.采用葡萄糖定量法分析模型检测微渗漏值.结果 体视显微镜下两实验组对根分叉外形修复均达到了良好效果.SEM观察显示PC和MTA与牙体组织之间均可见不连续的微间隙存在,PC与牙体组织间隙宽度为(7.363±2.159) μm,MTA与牙体组织间隙宽度为(8.693±3.551) μm,两者无明显差异(P＞0.05).在观察期内,虽然PC组的微渗漏值小于MTA组,但无统计学差异(P＞0.05).结论 PC与MTA修复髓室底穿孔的封闭效果相当,且PC价格低廉,不易使牙体变色,可以考虑作为MTA替代材料进一步研究.

Experimental study of furcal perforation repair with Portland cement

Objective To evaluate the effect of furcal perforation repaired with Portland cement (PC) by comparing to those repaired with mineral trioxide aggregate (MTA).Methods Fifty-three newly extracted human molars were collected and randomly divided into 2 experimental groups:group PC (n =24),group MTA (n =24) and a negative control group (n =5).Perforations in diameter of 2 mm were prepared at the central pulp chamber floor repaired with PC and MTA,respectively.No perforations were created in the control.The furcation appearances were observed under stereomicroscope after repairing.The interfaces between material and dentin were observed with scanning electron microscope (SEM),and the width of interface gaps was measured.Microleakage was tested by glucose oxidase detection.Results The fineness of furcation appearance after repairing was observed.Some discontinuous microgaps between the material and dentin were found in group PC and group MTA under SEM.The gaps in group PC and group MTA were 7.363±2.159 and 8.693 ± 3.551 μm respectively,which was not significantly different (P ＞ 0.05).In observation period,the value of microleakage in group PC was less than group MTA,but there was no statistical difference (P ＞ 0.05).Conclusion The effect of PC and MTA for repairing furcal perforation was similar.Nevertheless,PC is advantageous for its cheaper price and less coloration of the teeth,which makes it a substitute of MTA in the future study.