The fate of buccal bone around dental implants. A 12-month postloading follow-up study

Abstract

Introduction and aim: Buccal bone thickness is considered to be an important factor during implant surgery. Its resorption might have an effect on the soft tissue stability and eventually on implant survival. This study aimed to investigate the resorption of the buccal bone over the first 12 months after implant loading. Materials and methods: Twenty-four subjects (47 implants) were included. The buccal bone thickness was measured during implant surgery at several distances from the implant shoulder using a specifically designed device which allows buccal bone thickness measurements without the elevation of a muco-periostal flap. These measurements were repeated after 12 months of loading. Sixteen implants were placed flapless and 31 with the elevation of a flap. Of the latter, 19 were placed following a one-stage protocol and 12 following a two-stage protocol. Results: The mean reduction in buccal bone thickness, when all groups pooled, was 0.26, 0.36, 0.35 and 0.27 mm at the shoulder and 2, 4 and 6 mm apically. Implants with initial bone thickness <1mm (thin buccal plate) did not lose significantly more bone than those with an initial thickness ≥1mm (thick bone plate) except in the ‘open-flap, one-stage’ group (P = 0.009). A flapless procedure leads to less bone resorption compared to an open-flap procedure (P = 0.03). However, the number of surgeries (one stage vs. two stages) did not influence the rate of bone resorption (P = 0.23). Conclusion: Within the limitations of this study, one might question the necessity of having a thick bone plate at the vestibular site of the implant.