在模拟牙根表面再吸收缺陷的情况下，根管内矿三氧化物聚合体和氢氧化钙在四周内对 pH 值变化的影响：一项使用配对人牙的体外研究。

Effects of intracanal mineral trioxide aggregate and calcium hydroxide during four weeks on pH changes in simulated root surface resorption defects: an in vitro study using matched pairs of human teeth.

机构信息

Department of Endodontology, School of Dentistry, Oregon Health & Science University, Portland, OR 97239, USA.

出版信息

J Endod. 2011 Jan;37(1):40-4. doi: 10.1016/j.joen.2010.09.003.

DOI:10.1016/j.joen.2010.09.003

PMID:21146074

Abstract

INTRODUCTION

Diffusion of hydroxyl ions from intracanal calcium hydroxide (CH) through dentin is used to arrest external inflammatory root resorption. However, long-term and short-term CH placement has been associated with an increased risk of root fracture. Intracanal mineral trioxide aggregate (MTA) might provide an alternative to CH as a source of hydroxyl ions. This in vitro study compared the effects of intracanal MTA and CH on hydroxyl ion diffusion through dentin by measuring pH changes over time in simulated root surface resorption defects prepared in matched pairs of teeth; the null hypothesis tested was that there is no difference.

METHODS

Root surface cavities were prepared 5 mm from the apex in extracted human permanent anterior teeth (21 matched pairs) and 7 additional teeth (controls). Root canals were instrumented to size 50/.04 and filled with either tooth-colored MTA (ProRoot) or CH (UltraCal XS); control teeth were filled with saline. The pH in root surface cavities was measured at 3 hours, 24 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks.

RESULTS

In controls, pH readings did not differ significantly during the 4 weeks (P > .05, repeated-measures analysis of variance [ANOVA]). For the experimental intragroup effects, significant pH changes occurred over time in the MTA group (P = .005, repeated-measures ANOVA) and the CH group (P < .0001). For the experimental intergroup effects, the overall mean pH was higher in the MTA group (8.66; standard error [SE], 0.07) compared with the CH group (8.46; SE, 0.07) (P = .014, paired t test). At 4 weeks pH was higher in the MTA group (8.30; SE, 0.16) compared with the CH group (7.90; SE, 0.11) (P = .011); at all other time points intergroup differences were insignificant. The null hypothesis was rejected.

CONCLUSIONS

Intracanal MTA and CH groups differed in their overall effect on pH measured in simulated root surface resorption defects. At 4 weeks intracanal placement of MTA compared with CH resulted in a small but significantly higher pH.

摘要

简介

从根管内氢氧化钙（CH）向牙本质扩散的羟基离子用于阻止外部炎症性牙根吸收。然而，长期和短期 CH 放置与根折风险增加有关。根管内三氧化矿物聚合体（MTA）可能是 CH 作为羟基离子来源的替代物。本体外研究通过测量在匹配的前牙中制备的模拟牙根表面吸收缺陷中随时间变化的 pH 值变化，比较了根管内 MTA 和 CH 对羟基离子通过牙本质扩散的影响；检验的零假设是没有差异。

方法

从根尖处提取的人类恒牙前牙（21 对匹配牙）和另外 7 颗牙（对照组）制备根尖表面腔，根尖表面腔距离根尖 5 毫米。根管用 50/.04 牙色 MTA（ProRoot）或 CH（UltraCal XS）填充；对照组牙用生理盐水填充。在 3 小时、24 小时、1 周、2 周、3 周和 4 周时测量根尖表面腔的 pH 值。

结果

在对照组中，4 周内 pH 值无显著差异（P >.05，重复测量方差分析[ANOVA]）。对于实验组内组间效应，MTA 组（P =.005，重复测量 ANOVA）和 CH 组（P <.0001）随时间 pH 值显著变化。对于实验组间组间效应，MTA 组的平均 pH 值总体上高于 CH 组（8.66；标准误差[SE]，0.07）（P =.014，配对 t 检验）。在 4 周时，MTA 组的 pH 值（8.30；SE，0.16）高于 CH 组（7.90；SE，0.11）（P =.011）；在所有其他时间点，组间差异均不显著。零假设被拒绝。