MTA用于犬牙直接盖髓术的组织学观察

目的 通过组织学观察，比较MTA（Mineral Trioxide Aggregate)和氢氧化钙制剂(Dycal)在直接盖髓时对牙髓的影响。方法 3条健康杂种犬尖牙12颗，随机分为2组：MTA，Dycal。用裂钻在尖牙唇侧颈部穿髓后以MTA和Dycal盖髓，GIC修复牙体缺损。4个月后将犬处死取下尖牙，常规制作组织切片，观察牙髓炎症反应和牙本质桥形成情况。结果 MTA盖髓的实验组中，5／6无炎症或仅有轻度炎症反应，该组所有标本均有牙本质桥形成。Dycal盖髓的对照组牙髓均有轻度或中度的炎症反应，只有2例出现了牙本质桥。结论 MTA具有良好的生物相容性，适用于直接盖髓术，有望替代现有的盖髓材料。

Using Mineral Trio xide Aggregate as a Direct Pulp-Capping Material in Dogs

Objective The purpose of this study was to compare the dental pulp responses in dogs after MTA(Mineral Trioxide Aggregate)and a calcium hydroxide(Dycal)were applied as pulp-capping materials.Methods Twelve cuspids in three healthy adult beagle dogs were divided into two groups randomly.MTA or Dycal was used to repair the exposed site which was created with a fissure bur in a high-speed handpiece with copious water spray at the labial cervical access.Then the cavity was filled with glass ionomer cement(GIC).Four months later,the specimens were processed for histologic examination to observe the pulpal inflammation and dentin bridge formation.Results Five of six samples capped with MTA were free of pulpal inflammation,and all of samples in this group had dentin bridge formation.In contrast,all of samples capped with Dycal showed pulpal inflammation,and dentin bridge formation occurred in only2samples.Conclusion MTA is a biocompatible material which can promote dentin bridge formation.It can be used as a direct pulp-capping material during vital pulp therapy.