Effects of Bone Augmentation on Implant Success and Survival: A Retrospective Analysis With 6-Year Mean Follow-Up

To compare the clinical, radiographic, esthetic outcomes, and success and survival rates of dental implants placed after bone augmentation techniques.

This retrospective study included a total of 764 patients receiving 764 dental implants between 2009 and 2019. Four hundred implants were placed without bone augmentation (control), and 364 were placed after bone augmentation. Bone augmentation techniques were guided bone regeneration (GBR), ridge split, and onlay bone grafting. Gingival index (GI), plaque index (PI), probing depth (PD), bleeding on probing (BOP), pink esthetic score (PES) and marginal bone loss (mm) and area (mm²) were measured. The study variables of the implants among augmentation groups were compared statistically.

The mean PI and GI scores, and BOP values of the implants in the augmentation and control groups were comparable (p = 0.365, p = 0.230, and p = 0.371 resp.) The mean PD scores of the implants were 2.82 ± 1.22 in the augmentation and 2.54 ± 1.29 in the control groups; the difference was significant (p = 0.002). The mean vertical bone loss of the implants was 0.78 ± 0.70 in augmentation and 0.82 ± 0.82 in the control groups, which was comparable (p = 0.461). The mean PES total values of the implants were 8.30 ± 1.55 in augmentation and 10.04 ± 2.43 in the control groups; the difference was significant (p < 0.001). There were no significant differences between the augmentation and control groups in implant survival (99.18% vs. 98%, p = 0.228) and success (82.97% vs. 85.50%, p = 0.389) rates. Significant differences in some study variables were observed among the augmentation groups. The survival and success rates of the implants in GBR (99.21% and 85.04%), ridge split (99.19% and 79.68%), onlay (99.12% and 84.21%), and control (98.00% and 85.50%) groups were similar (p = 0.630 and p = 0.479, resp.) in the 6-year mean follow-up.

The implants placed in augmented bone showed similar cumulative success and survival rates compared to implants placed in natural bone with a 6-year mean follow-up. The augmentation group showed lower esthetic scores. There are some differences in clinical parameters among augmentation groups; however, all the augmentation groups showed similar success and survival rates.