Implant Treatment for Severe 3-Dimensional Bone Defects in the Area of Missing Adjacent Maxillary Central and Lateral Incisors: Long-Term Follow-Up Using Titanium Mesh and GBR Techniques.

This report presents 2 cases of severe bone defects following the extraction of adjacent maxillary central and lateral incisors. In both cases, the teeth were extracted in the hospital's oral surgery department due to extensive apical periodontitis. Postoperatively, 3-dimensional bone defects were observed, including mesiodistal, labial, and palatal bone loss extending near the nasal floor. In the first case, 2 implants were placed using the guided bone regeneration (GBR) method with titanium mesh. Subsequently, during the second stage surgery, a minor GBR procedure was performed to improve the contour of the implant neck. In the second case, in which the bone defect was even more severe than in the first, a multi-GBR approach was selected. After the initial GBR procedure, insufficient bone formation was observed in the central area of the defect. To address this, the ice cream cone technique was employed to enhance bone regeneration. Subsequently, 2 implants were placed. After implant placement, a vertical concavity was observed between the necks of the 2 implants. To correct this, a second GBR procedure using titanium mesh was performed as in case 1. However, an interimplant black triangle was observed, and a vascularized interpositional periosteal-connective tissue flap was performed to eliminate it. Both cases have been followed for more than 6 years since the placement of the final prostheses with no significant findings in intraoral examinations or cone beam computerized tomography images. Esthetically, no interimplant black triangle was observed. In case 1, a satisfactory outcome was achieved by remaking the prostheses. However, in case 2, which had a more severe bone defect than case 1, the clinical crown length of the prostheses is slightly longer compared with the contralateral side.