Abstract
Aim: to develop a model for regenerative endodontics using newly-weaned Wistar rats immature molars with pulp necrosis to histologically describe the evolution of apical tissues following treatment with a bi-antibiotic paste, induced bloodclot formation and MTA. Methods: Ten 25-day-old female Wistar rats were divided into an initial control group (Ci) and two experimental groups in which pulp necrosis was experimentally induced on the left mandibular first molar by exposing the pulp chamber and leaving it open to the oral environment. One of the experimental groups was left untreated (E1) while the other was submitted to a protocol of regenerative endodontics 10 days thereafter (E2). Fifteen days after placement of a bi-antibiotic paste, bleeding was induced into the root canal space and MTA was placed upon. Animals were euthanized 30 days later. Right mandibular first molars served as an 80-day-old final control group (Cf). Each hemimandible was histologically processed to analyse parameters associated with root development. Statistical analysis was carried by means of ANOVA; p values below 0.05 were considered statistically significant. Results: baseline (i.e. 25-days old) mean root length and apical diameter of the distal root canal were 1.84±0.25 and 0.38±0.02mm respectively. Following the regenerative endodontic protocol, cells lining the walls of the root canal and significant increase to both length (2.37±0.22mm) and diameter (0.32±0.03 mm) were observed. Conclusions: newly-weaned Wistar rats serve as a suitable model to evaluate regenerative endodontic protocols. However, further research is needed in order to disclose the nature of the cells and/or cell mediators involved.
Highlights
The American Association of Endodontists has defined regenerative endodontic therapy as “biologically based procedures designed to replace damaged structures, including dentine and root structures, as well as cells of the pulp-dentine complex”[1]
Mean values for root canal length and apical diameter of the canal of the distal root of the mandibular first molar are shown in Table 1; statistically significant differences were found between Ci and Experimental group 2 (E2) (p
Stem cell research brought along new therapeutic approaches to treat immature permanent teeth with a diagnosis of pulp necrosis
Summary
The American Association of Endodontists has defined regenerative endodontic therapy as “biologically based procedures designed to replace damaged structures, including dentine and root structures, as well as cells of the pulp-dentine complex”[1]. Considering the core principles of tissue engineering, - a triad that includes an appropriate source of stem/progenitor cells, growth factors, and scaffolds – regenerating functioning pulp tissue would be the ideal therapeutic approach when treating immature teeth with open apexes and a diagnosis of pulp necrosis[3,4]. Immature open apexes are richly vascularised and some cells of the apical papilla and Hertwig’s Epithelial Root Sheath (HERS) might be able to survive infection[5]. If noxious stimuli are removed, these cells become able to proliferate in proximity to the periapical tissues leading to the regeneration of radicular and periradicular tissues such as alveolar bone, periodontal ligament, cementum and dentine-pulp complex thereby allowing the root to mature increasing both in length and thickness[6]. Considering human samples are difficult to harvest, animal models might contribute to shedding some light on this matter and identifying cell populations as well as the intrinsic and extrinsic factors that might participate in the process of apexogenesis/maturogenesis[6,8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
