Regenerative treatment of an immature tooth with an abscess using activated irrigation: A case report

INTRODUCTION. An immature permanent tooth with pulp necrosis, an open apex, and an acute apical abscess presents a treatment challenge. This case describes a regenerative approach combining canal disinfection, activated irrigation, and a blood-clot scaffold. PURPOSE. To describe the treatment and follow-up of an immature mandibular right second premolar with pulp necrosis and an acute apical abscess in a 10-year-old boy. CASE DESCRIPTION. The patient presented with pain, swelling, and purulent drainage associated with tooth 45. Periapical radiography and cone-beam computed tomography showed an open apex and extensive periapical radiolucency. Initial treatment comprised drainage, saline irrigation, light instrumentation with 2% chlorhexidine gel, and an intracanal dressing of calcium hydroxide with 2% chlorhexidine gel. At the second visit, 15 days later, the dressing was removed and 17% EDTA was activated with Easy Clean for three cycles of 60 seconds. Apical bleeding was induced, followed by placement of a collagen matrix, MTA HP Repair, and a composite restoration. RESULTS. Follow-up showed symptom resolution, periapical healing, increased root length, and dentinal wall thickening. The treatment timeline describes follow-up at 3, 6, and 10 months, and the case narrative reports maintained healing and tooth function at two years. CONCLUSION. This case was associated with symptom resolution, periapical healing, and continued root development after regenerative treatment. A single case cannot establish the independent contribution of irrigant activation or the predictability of the protocol.