(TC11) Regenerative Endodontic Procedures for Necrotic Mature Teeth: Three Cases of Successful Healing of Apical Periodontitis and Recovery of Periodontal Ligament

Abstract: Regenerative endodontic procedure(REP) is used to treat immature teeth with pulp necrosis and apical periodontitis. REP preserves the potential for root development by promoting pulp-dentin compositions in the apical papilla. Despite growing evidence of REP as an alternative for conventional root canal therapy for mature teeth, its success rate remains variable. We report a case series of successful REP on three mature teeth with necrotic pulp and external inflammatory root resorption. Three female patients: age 27 tooth#7, age 25 tooth#9, and age 58 tooth#23 with necrotic pulp and external inflammatory root resorption were treated with REP according to the AAE Clinical Consideration for a Regenerative Procedure with a few modifications. At the first visit, the apical size was enlarged to minimal 0.6mm in diameter. All canals were cleaned and shaped by XP finisher and 1.25% NaOCI and Ca(OH)2 were placed. At the second visit within 4 weeks, Ca(OH)2 was removed by 20ml of EDTA for 1min. K-file was over-instrumented into the periapical tissues to induce bleeding and their specimens were collected for culturing. At the 3-month follow-up, all three patients were completely asymptomatic, and their periapical X-rays demonstrated decreased size of periapical radiolucency and recovery of periodontal ligament(PDL) around the area with external root resorption. REP effectively healed apical periodontitis in the short term by achieving clinical recovery, resting external root resorption, and recovering the periodontium. Long-term follow-up with Cone Beam Computed Tomography and evaluation of the blood clot specimens can help study the mechanism of revascularization.