Endodontic treatment of primary molars is a great challenge to the dentists because of their complex morphology. However, there have been limited controlled in vivo studies about filling materials for primary teeth. Hence, the aim of this study is to evaluate and compare histologic responses of different calcium hydroxide canal filling materials that are used in daily clinical practice. Pulpectomies were performed in 132 teeth of the dogs. The root canals were randomly filled with either Vitapex ® (n = 44), Metapex ® (n = 44), or Metapaste ® (n = 44). After 4 or 13 weeks, respectively after operation, the dogs were sacrificed, and teeth were processed for histologic examinations. Inflammatory reaction was evaluated and scored in a blind manner. The Fisher's exact test and Kruskal-Wallis test were used to compare the tested groups. In 4-week-group, all inflammatory responses were in normal range except for fibrosis. In 13-week-group, increased response to various inflammation reaction was shown compared to the 4-week-group. However, there were no statically significant differences between the tested groups in all inflammatory reaction. Overall, there were no significant differences among three materials in responses of apical tissues and all of them showed favorable tissue responses.

The pulp treatment of primary and immature teeth in the children and adolescents is affected by the environment of the patients, clinical careers and dentists performing the techniques, as well as clinical modalities and pulpal diagnosis. The purpose of this study was to investigate the current status of pulp treatment performed in real clinical practice, as well as the reasons behind the choice of treatment methods.The study was conducted on a total of 153 members of the Korean Academy of Pediatric Dentistry, and statistical data from the Health Insurance Review and Assessment Service (HIRA) from 2010 to 2018 were analyzed together. Both the survey results and the statistics from the HIRA showed that 1-visit pulpectomies of primary teeth were most common, and the frequency of the use of the Ni-Ti file was increased in children with primary or mixed-dentition. In the treatment of immature permanent teeth, regenerative endodontic treatment by individual dentists was found to be less frequent than in university hospitals.