Effect of Different Therapies on Root Formation of Traumatic Incisors

Objectives: To compare the influence of different treatments on root development and formation of immature permanent incisors with dental trauma.
Methods: In this retrospective study, we collected 711 radiographs of dental trauma from image database system of West China School of Stomatology (Jul. 2016 -Dec. 2017). After cases were excluded using pre-defined inclusion and exclusion criteria, 21 indirect pulp capping, 48 pulpotomy and 58 apexification were included. NIH ImageJ with TurboReg plug-in was used to correct angular differences between the preoperative and recall images, and the calculation of variations of root length, dentinal wall thickness and apical closure tendency was evaluated by ImageJ and presented in percentage. Kruskal-Wallis ANOVA followed by stepwise step-down comparisons were applied to compare the changes of root morphology among different treatment group. Besides, the type of apical closure was also figured qualitatively and analyzed using chi-square test.
Results: Apexification group showed weaker apical closure trend compared with the other two groups. It also showed thinner dentinal wall thickness in apexification group compared with the pulpotomy group but no difference with indirect pulp capping group. Pulpotomy and indirect pulp capping has no significant difference in apical closure trend and dentinal wall thickness. However, there were no significant differences in the development of root length among three groups. In addition, there was a moderate correlation between the treatment and the type of apical closure. Pulpotomy was inclined to form normal apical constriction rather than dentin bridge, however, apexification was inclined to form dentin bridge rather than normal apical constriction. And indirect pulp capping has no specific inclination to any closure types.
Conclusions: Apexification results in an abnormal root development mostly by effecting the dentinal wall thickness and apical closure rather than root length. Pulpotomy is more beneficial to the normal root development of immature traumatic teeth.