Aim: This study has been implemented in order that the prevalence and pattern of root resorption in mandibular primary molars previously treated with formcresol pulpotomy could be assessed compared with that takes place in apparently sound contralateral teeth.
Subject and methods: The current retrospective cross sectional study has been fulfilled on a sample of 270 periapical radiographs of 118 children (55 females and 63 males) who have been treated at Pediatric Dentistry Department, at the Faculty of Dentistry, Cairo University. All radiographs were screned based on the method presented by Moorrees et al. for purpose of evaluating the process of root resorption . The root resorption process was divided into 5 stages.
Results : It was shown by the results of study that no difference among root resorption between treated and non-treated teeth existed in most of the cases (91 cases). Whereas, accelerated and delayed root resorption were presented by 36 and 8 of cases, consecutively.
Conclusion: It was concluded through investigation in this study that the prevalence of abnormal root resorption in the mandibular primary molars that was previously treated with formcresol pulpotomy was 32.6 %.