Autogenous bone ring augmentation around single tooth implantation in the esthetic zone: A retrospective case series study with 2–3 years of follow-up

Background: /purpose: Bone ring technique (BRT) is an effective method to reconstruct alveolar bone defects with simultaneous implant placement. This study aimed to evaluate the efficacy of the BRT in single maxillary anterior tooth implantation and its esthetic outcomes over 2–3 years of follow-up. Materials and methods: Fifteen patients with single maxillary incisor loss received autogenous BRT with simultaneous implant placement. The vertical/horizontal bone gain, remaining vertical bone height (RVBH), remaining buccal bone width (RBBW), and vertical/horizontal bone resorption around implant over 2–3 years of follow-up were measured by using cone-beam computed tomography. Esthetic results including white esthetic score (WES), pink esthetic score (PES), and papilla index (PI) were evaluated by clinical recorded photographs. Results: All implants showed evidence of osseointegration, and the mean vertical and horizontal bone gain of 14 sites was 5.55 ± 0.87 mm and 4.73 ± 0.70 mm, respectively. During 2–3 years of follow-up, all mean values of RBBW were more than 2 mm. Main vertical bone loss appeared within 4 months after surgery and the RVBH value decreased as the follow-up duration continued. Maximum buccal bone thickness resorption mostly appeared in the middle level of the implant during the primary two follow-up periods (P < 0.05). Esthetic results showed that the mean WES/PES was higher than 17, and more than half cases demonstrated relatively high PI (3 points) throughout the follow-up. Conclusion: BRT could achieve excellent bone augmentation effect and can offer predictable esthetic outcomes for single tooth implant restoration in the esthetic zone.