全冠牙体预备后影响牙髓-牙本质复合体反应因素的研究

目的:观察全冠牙体预备后牙髓牙本质复合体的反应及剩余牙本质厚度和修复时间对牙髓的影响。方法:选择因正畸需要拔除的健康第一前磨牙38颗,根据牙体制备的深度不同分为3组,暂时冠修复后分别于术后1,3,6周后拔除观察牙髓的炎症反应及剩余牙本质厚度。结果:全冠牙体预备后,牙髓组织主要表现为轻、中度的炎症反应。6周左右可见修复性牙本质形成。剩余牙本质厚度影响牙髓的反应,牙本质越厚,牙髓重度炎症的发生率越低(P<0.05)。结论:术后观察时间对牙髓预后的影响是以剩余牙本质的厚度为前提,剩余牙本质小于2mm时,时间与牙髓反应关系密切(P<0.01)。剩余牙本质为2～2.5mm时,时间与牙髓的反应相关(P<0.05)。但剩余牙本质厚度大于2.5mm时,时间与牙髓反应无关。

Factors Influencing Pulpal-dentin Complex Response after Crown Preparation

Objective: To determine the importance of the remaining dentin thickness, preparation depth and post-operative time on the pulpal inflammation after the crown preparation. Methods: 38 human bicuspids scheduled for extraction for the orthodontic reasons were selected for this study. The teeth were divided into 3 groups according to different preparation depth. After the periods of 1, 3 and 6 weeks of post-operative, the severity of the pulpal reaction was ranked and the remaining dentine thickness was measured. The influence of the remaining dentin thickness and post-operative time on pulpal reaction severity was compared by statistical methods. Results: The mild and moderate inflammation was present in the pulp tissue after crown preparation. In the sixth week, reparative dentin deposited at the border of pulp and dentin. The remaining dentin thickness was correlated with the pulpal response and as the remaining dentin was thinner, the pulp inflammation increased(P<0.05). Conclusion: When the remaining dentin thickness was less than 2 mm, the severity of pulp reactions closely corelated with time. But when the thickness was superior to 2.5 mm, pulp reaction has no correlation with post-operated time.