Abstract
The present case describes the successful healing of a periapical lesion associated with the left maxillary lateral incisor (# 22, Federation Dentaire Internationale) having a type 3b dens invaginatus tooth morphology. The treatment was complicated by the presence of blunderbuss root apex and large periapical lesion (>10 mm) with through and through bone defect (Bucco palatal cortical bone perforation, Von Arx Type 1b). An adolescent boy reported palatal swelling and pus discharge in relation to tooth #22. A thorough clinical and radiographic examination revealed tooth #22 as having a type 3b dens invaginatus with an open apex and a diagnosis of pulp necrosis and acute apical abscess. The case was managed by non-surgical root canal treatment followed by endodontic surgery using principles of guided tissue regeneration. A 5-year recall revealed an asymptomatic functional tooth with complete healing.