Survival Rates and Bone and Soft Tissue Level Changes Around One-Piece Dental Implants Placed with a Flapless or Flap...

The purpose of the current study was to determine the survival rates and to measure marginal bone changes and peri-implant conditions 8.5 years after placement of one-piece implants with an anodically oxidized surface (AOS). A total of 52 subjects who received a one-piece implant with an AOS using a flapless or flap protocol and completed a previous randomized clinical trial were contacted for a recall visit 8.5 years after implant placement (T_8.5). Implant success and survival rates, probing pocket depth (PPD), presence of bleeding on probing (BoP), papilla level, and incidence of complications and peri-implant disease were assessed by a single, blinded examiner. A second blinded examiner evaluated marginal bone level changes. Results for 8.5 years were compared to those at the time of implant placement, implant loading (0.5 year), and 1 and 1.5 years follow-up. The results based on 28 patients who attended the follow-up visit (half had flapless and half a flap protocol) showed a 100% implant survival rate and a 96.4% implant success rate 8.5 years after implant placement using one-piece implants, with no difference in survival and success rates between the flapless and the flap protocol. During the same follow-up period, a significant increase in crestal bone height from 1.5 to 8.5 years was observed. Analysis suggested decreasing mean levels of bone loss with time (P < .001). Moreover, there was 0.8 to 1.0 mm of bone loss through year 1.5, which decreased to 0.3 mm at 8.5 years (P < .05). There was no statistically significant difference in PPD or BoP over time. Similar mean levels of PPD were found in flap and flapless groups (mean [SD] = 2.4 [0.3] and 2.2 [0.4] mm, respectively [P = .18]), as well as similar rates of BoP (22.8% vs 17.9%, respectively). Papilla levels increased during the first year after implant loading. However, there was little additional change between 1.5 and 8.5 years. A total of eight fractured porcelain crowns and three crown loosenings were reported. One-piece implants with an AOS showed high survival rates and stable marginal bone and periimplant soft tissue levels regardless of whether a flapless or flap protocol was used.