Implant placement after marsupialization of a dentigerous cyst

This paper presents a case of a dentigerous cyst accompanied by a history of inflammation, resorption of the roots of the first molar and the lingual aspect of the distal root of the second molar, and devitalization of the 2 premolars. The treatment option chosen was marsupialization of the cyst, extraction of the involved teeth, endodontic treatment of both premolars, and implant insertion in the area of the first mandibular molar at a later stage. Twelve months postsurgery the area of interest was almost flattened and the radiographic examination revealed total disappearance of the radiolucency. An implant of 15 x 4 mm was inserted in the area of the first mandibular molar. Despite the excellent implant stability achieved, a thin central zone of the defect remained void of bone. After complete excision of soft tissue the defect was filled with an alloplastic bone substitute. Eight months later (20 months postsurgery), the implant was uncovered and the restorative procedure completed. The implant and the crown have been functioning sign and symptom free for 48 months. Marsupialization was preferred instead of enucleation due to (1) proximity of the cyst to the mandibular canal; (2) need for apicectomy of both premolars to gain good access for enucleation; (3) refusal of the patient to undergo a second surgery for bone harvesting; (4) lower probability for postoperative contamination; (5) need of small quantity of bone substitute; (6) easier extraction of the impacted second molar due to its coronal movement. The disadvantages of the treatment were the long healing period and the discomfort of the patient at the early stages of marsupialization. It was judged that the advantages outweighed the disadvantages in this case. We discuss the findings of other authors who support the conservative approach to jaw cysts in a young population, and the concerns that exist in the literature about the ability of osseoconductive graft materials to generate vital bone and achieve implant-to-bone contact.