Torabinejad Mahmoud, Faras Hadi, Corr Robert, Wright Kenneth R, Shabahang Shahrokh
Loma Linda University, Loma Linda, California.
Loma Linda University, Loma Linda, California.
J Endod. 2014 Apr;40(4):515-20. doi: 10.1016/j.joen.2013.12.025. Epub 2014 Feb 12.
A growing body of evidence is building a case for the possibility of tissue regeneration within the root canal of necrotic teeth, allowing for continued root development. However, it remains unknown what type of tissue is produced after regenerative endodontics. The purpose of this study was to use blood clots and platelet-rich plasma (PRP) as scaffolds in regenerative endodontics under ideal conditions in a ferret model to examine the tissues generated within the root canals.
The pulps of 21 canine teeth from 7 young ferrets were extirpated using broaches without filing the canal walls. Bleeding was stimulated from the periapical tissues, and a blood clot was induced in the canal space to the level of the cementoenamel junction in 12 teeth. PRP was prepared and placed in the canals to the level of the cementoenamel junction in 9 teeth. The coronal access was sealed with mineral trioxide aggregate. Seven canines were not operated on and served as controls. Three months later, block sections including each canine and its surrounding tissues were removed for histologic evaluation. The tissues found in the canals of experimental teeth were compared with those in the control teeth.
Almost all of the experimental teeth showed the presence of intracanal bonelike tissue. No evidence of dentinal wall thickening or apical narrowing was noted in the experimental teeth.
In this experimental model, the use of either PRP or blood clots during regenerative endodontics leads to the formation of intracanal bonelike tissue without continual root maturation.
越来越多的证据表明,坏死牙髓的根管内存在组织再生的可能性,从而使牙根能够继续发育。然而,再生牙髓治疗后产生的是何种组织仍不清楚。本研究的目的是在雪貂模型的理想条件下,将血凝块和富血小板血浆(PRP)用作再生牙髓治疗的支架,以检查根管内生成的组织。
使用拔髓针去除7只幼年雪貂的21颗犬齿牙髓,不锉磨根管壁。刺激根尖周组织出血,在12颗牙齿的根管内诱导形成血凝块至牙骨质牙釉质界水平。制备PRP并将其放置在9颗牙齿的根管内至牙骨质牙釉质界水平。用三氧化矿物凝聚体封闭冠方入口。7颗犬齿未进行手术作为对照。3个月后,取出包括每颗犬齿及其周围组织的块状切片进行组织学评估。将实验牙齿根管内发现的组织与对照牙齿的组织进行比较。
几乎所有实验牙齿的根管内均出现类骨组织。实验牙齿未发现牙本质壁增厚或根尖狭窄的证据。
在该实验模型中,再生牙髓治疗期间使用PRP或血凝块均可导致根管内类骨组织形成,而牙根无持续成熟。