Torabinejad Institute of Surgical Education and Research Venues, Irvine, California.
Private practice, Los Angeles, California.
J Endod. 2018 Dec;44(12):1796-1801. doi: 10.1016/j.joen.2018.09.005.
Current pulp revascularization procedures in teeth with necrotic pulps and open apices have produced histologic evidence of connective tissue growth, cementum, and bone within the root canals of experimental animals. This study aims to investigate the effect of maintaining uninflamed residual apical pulp tissue on the histologic outcome of pulp-dentin complex regeneration after a revascularization procedure in immature ferret cuspid teeth.
Twenty-eight cuspid teeth from 7 young male ferrets were used in this experiment. Seven teeth were reserved to serve as positive control samples without any treatment. In another 7 teeth, the pulp was completely extirpated (negative control), whereas the pulp of the remaining 14 teeth were removed to either 1-2 mm short of the apex (7 samples) or 2-4 mm short of the apex (7 samples). Blood clots were covered with mineral trioxide aggregate at the cementoenamel junction level of each tooth. Three months later, block sections were removed for histologic evaluations, and the data were statistically analyzed with the chi-square test (P < .05).
All teeth with complete pulp extirpation showed the presence of bone inside the root canal. In contrast, the root canals for most teeth with pulp amputation 1-4 mm from the radiographic apex were filled with normal pulp, which extended coronally to the mineral trioxide aggregate, where hard tissue bridges had formed.
Based on these results, we concluded that regeneration of the pulp-dentin complex is possible when the apical 1-4 mm of the apical pulp remains intact in immature teeth.
目前对于有坏死牙髓和开放根尖的牙齿，牙髓血运重建术已在实验动物的根管内产生了结缔组织生长、牙骨质和骨的组织学证据。本研究旨在探讨在不成熟雪貂尖牙牙髓血运重建术后，保留未发炎的根尖残留牙髓组织对牙髓-牙本质复合体再生的组织学结果的影响。
本实验使用了 7 只年轻雄性雪貂的 28 颗尖牙。7 颗牙作为阳性对照样本，不做任何处理。在另外 7 颗牙中，牙髓被完全切除（阴性对照），而其余 14 颗牙的牙髓则被切除至根尖 1-2mm（7 个样本）或根尖 2-4mm（7 个样本）处。每个牙的牙骨质-釉质交界处用三氧化矿物聚合体覆盖血凝块。3 个月后，取出块状切片进行组织学评估，并采用卡方检验对数据进行统计学分析（P<0.05）。
所有牙髓完全切除的牙都显示根管内有骨。相比之下，牙髓切除术切除根尖 1-4mm 处的牙根管内大部分都填充了正常牙髓，牙髓向冠方延伸至三氧化矿物聚合体，在该处形成了硬组织桥。
根据这些结果，我们得出结论，当未成熟牙的根尖 1-4mm 处的根尖牙髓保持完整时，牙髓-牙本质复合体的再生是可能的。
