Reparative Dentin Formation Using Stem Cell Therapy versus Calcium Hydroxide in Direct Pulp Capping: An Animal Study

Abstract Direct pulp capping process is a therapeutic method aimed at maintenance of pulp vitality and health by using a biocompatible material placed directly over the exposed pulp. The aim of this study was to evaluate and compare the effect of direct pulp capping procedures by dental pulp stem cells (DPSCs) or calcium hydroxide on dentin tissue formation. Three mongrel dogs were used as experimental model. Two access cavities were prepared in the right and left mandibular fourth premolars in all dogs to expose and extirpate the pulp tissues which were processed in the lab to obtain a single-cell suspensions. The isolated cells were cultures in odontogenic medium for subsequent differentiation. The maxillary teeth (3 incisors and one canine) of the corresponding dog number were subjected to class V cavities to expose their pulps which were assigned into 2 groups of 12 teeth each ( group I - pulp capping with calcium hydroxide) and (group II - pulp capping with dental stem cells DPSCs). The operated teeth were collected after 3 months and processed for histological and electron microscopic examinations. Specimens were subjected to elemental analysis of calcium and phosphorus. EDX elemental analysis revealed significant differences in the calcium and phosphorous wt, % in the reparative dentin of calcium hydroxide treated group which confirmed histologically. Direct pulp capping by DPSCs has shown promising generative potential for regaining normal dentin.

摘要 直接盖髓术（Direct pulp capping）是一种通过将生物相容性材料直接置于暴露牙髓上来维持牙髓活力与健康的治疗方法。本研究旨在评估并比较牙髓干细胞（dental pulp stem cells, DPSCs）与氢氧化钙用于直接盖髓术对牙本质组织形成的效果。实验选用3只杂种犬作为实验模型。为所有实验犬的左右下颌第四前磨牙制备2个窝洞，以暴露并摘除牙髓组织；随后将摘除的牙髓组织在实验室中处理以获得单细胞悬液。将分离得到的细胞接种于成牙本质培养基中培养，以进行后续分化。对应编号实验犬的上颌牙齿（3颗切牙与1颗尖牙）被制备为V类窝洞以暴露牙髓，并分为2组，每组12颗牙齿：I组采用氢氧化钙盖髓，II组采用牙髓干细胞（DPSCs）盖髓。术后3个月收集手术牙齿，进行组织学与电子显微镜检查。对标本进行钙与磷元素分析。能量色散X射线元素分析（EDX）结果显示，氢氧化钙治疗组修复性牙本质中的钙、磷质量百分比存在显著差异，该结果经组织学验证。采用DPSCs实施直接盖髓术展现出了恢复正常牙本质结构的良好再生潜力。