Dental bulge restoration and gingival collar expansion after endodontic treatment of a complicated maxillary fourth premolar crown-root fracture in a dog

This case report describes endodontic, restorative, and periodontal treatment of a complicated crown-root fracture of the right maxillary fourth premolar tooth in a dog. A buccal portion ('slab') had separated from the tooth, which extended subgingivally into root structure. Following completion of standard root canal therapy, a periodontal flap was elevated. Alveolectomy and alveoloplasty were performed, and inflamed soft tissues were debrided. The fracture site was prepared, restored, and shaped to receive a dental bulge contour. A gingival collar expansion technique was utilized to allow for apical positioning of gingiva at the distobuccal crown-root segment. Clinical and radiographic examination 15-months following treatment showed no evidence of endodontic failure. The restorations were intact, and periodontal probing depths were slightly increased probably due to gingival enlargement from concurrent cyclosporine therapy. The importance of biologic width maintenance in periodontal surgery and need for owner compliance with home oral hygiene are discussed.