Retrograde Vital Pulp Treatment in External Root Resorption Due to Third Molar Impaction: A Proof-of-Concept and Case Report

<b>Background/Aim</b>: Third molar impaction with the consequent root resorption of second molars often creates complexities in treatment planning and execution. In the past, the root canal treatment (RCT) of second molars was required in these cases to avoid pulp necrosis and infection. The aim of this paper is to report a surgical/retrograde approach for the maintenance of pulp vitality, proposed as retrograde vital pulp treatment (rVPT), in cases of asymptomatic or reversibly affected teeth with root resorptions caused by impacted adjacent teeth. <b>Methods</b>: A case report on the rVPT of two upper second molars with root resorption due to third molar impaction is presented. The chief complaint of the patient was a slight pain during bite involving the upper second molars. Heat and cold sensitivity tests were performed, suggesting a healthy pulp status. A cone beam computed tomography (CBCT) scan was performed to aid the diagnosis and treatment planning, showing bilateral upper third molar impaction and both distal roots of the upper second molars affected by external root resorption (ERR). In both cases, the third molar was surgically extracted, the surface of the root with ERR was smoothened and rVPT was carried out by performing a 3 mm retrograde preparation of the root canal and its retrograde sealing using a hydraulic calcium silicate-based cement (hCSCs). <b>Results:</b> Heat and cold sensitivity tests were performed 1 month, 3 months, 6 months and 1 year after the treatment. The patient reported no pain, and the pulp sensitivity was maintained in all follow-up periods. A CBCT scan was performed 24 months after the treatment, reporting a complete perirradicular endogenous bone apposition. <b>Conclusions</b>: Based on the successful clinical and radiographic outcomes observed in the present case after two years of follow-up, rVPT is proposed for the maintenance of pulp vitality in cases of asymptomatic or reversibly affected teeth with ERR caused by impacted adjacent teeth.