Outcomes of pulpectomy in the primary dentition and age-related morphological changes in the root canal of primary molars: A retrospective study

Abstract Objectives To investigate the factors influencing primary tooth survival after pulpectomy and to elucidate age-related morphological changes in the root canal of primary molars. Materials and Methods This retrospective study included 592 primary anterior teeth and 583 primary molars after pulpectomy. Survival analysis was performed to determine the predictors of pulpectomy failure. Cone-beam computed tomography (CBCT) data of the maxillary first primary teeth from 63 children aged 3–8 years were collected, and Spearman’s correlation and binary logistic regression were performed to assess age-related changes in canal morphology. Results Periapical periodontitis, Vitapex® filling, and non-general anesthesia treatment increased the failure risk of anterior primary teeth pulpectomy. Older age at treatment increased the primary molar pulpectomy failure risk. On CBCT analysis, the ratio of canal length to root length for the mesiobuccal (MB), distobuccal (DB), and palatal (P) roots negatively correlated with age (P<0.05). The ratio between the root canal wall area with inner diameter lesser than 0.15 mm and the whole root canal wall area (R.15) at plane D of the MB canals positively correlated with age (P<0.05). The number of discontinuous canals (Ndis) for the MB and DB roots increased with age and the canal area at plane D for MB and P canals negatively correlated with age (P<0.05). Conclusions Older age at treatment for primary molar pulpectomy and periapical lesions, non-general anesthesia treatment, and Vitapex® filling for anterior primary teeth pulpectomy may predict a higher failure risk. Age-related morphological changes in the primary molar root canal were evident and could be a reason for treatment failure.