ABSTRACT
Pulpal and periapical diseases are the common diseases in human diseases. The traditional treatment method for these diseases is root canal treatment, which is to completely remove and control infection, repair or prevent periapical lesions by root canal mechanical preparation, chemical disinfection and filling. At present, although root canal treatments have a high success rate, there are still a series of problems. Dental pulp regeneration has attracted more and more attention from researchers in promoting the formation of pulp-like tissue in root canals. The ultimate goal of regenerative endodontics is to form a functional endodontic-dentin complex with inner blood vessels and nerves, outer layers of dentin cells arranged along the root canal wall, and new dentin formed by secreting matrix, so as to restore pulp vitality. Stem cells, scaffolds, biosignal molecules, and regenerative microenvironment are key tissue engineering factors that affect pulp regeneration. In this paper, the strategies and applications of pulp regeneration were reviewed around the above factors and clinical procedures.
ABSTRACT
Objective Few studies are reported on the radicular groove and root canal variation of the mandibular first premolar.This study aimed to observe the root canal system and root variation of the mandibular first premolar by cone-beam computed tomography (CBCT).Methods We selected CBCT images of 643 mandibular first premolars of 336 patients and subjected the data obtained to statistical analysis.Results Of the 643 mandibular first premolars, 637 (99.1％) had a single root and the other 6 had double roots;502 (78.1％) had a single root canal, 133 (20.7％) had two, 5 (0.78％) had three, and 3 (0.47％) presented C-shaped root canal morphology.The average length of the 643 mandibular first premolars was (13.2±1.5) mm and the mean distance from the apical foramen to the anatomical apical end of the root was (0.93±0.35) mm.Totally, 123 (19.1％) of the mandibular first premolars had a radicular groove, of which 94 (76.4％) had double root canals and the root canal systems included typesⅠ in 24 (19.5％), Ⅱ in 2 (1.6％), Ⅲ in 19 (15.4％), Ⅳ in 1 (0.8％), Ⅴ in 69 (56.1％), and Ⅶ in 3 (2.4％).Conclusion The root canal system of the mandibular first premolar has a significant variation.CBCT can reveal the complex anatomical structure of the mandibular first premolar and provide reliable evidence for the root canal treatment.