Long-term marginal bone loss in 217 machined-surface implants placed in 68 patients with 5 to 9 years of follow-up: a retrospective study.

PURPOSE: The aim of the present study was to evaluate marginal bone loss (mBL) adjacent to dental implants with a machined surface with at least 5 years of function. MATERIALS AND METHODS: Machined-surface implants with a minimum follow-up of 5 years were included in the study. Recorded clinical parameters included plaque and gingival bleeding indices, smoking habit (nonsmoker, 0 to 10 cigarettes/day, or more than 10 cigarettes/day), presence of periodontal disease (healthy or periodontally compromised), and compliance with periodontal maintenance. Marginal bone loss (mBL) was assessed radiographically around the implants using the long-cone parallel technique. RESULTS: Sixty-eight participants who received 217 implants were included in the study. No late failures occurred. The mean duration of follow-up was 6.7 years (range, 5 to 9 years). The mean mBL after 5 to 9 years was 0.43 threads (± 1.12 threads) (0.26 mm). Thirteen implants (6.0%) showed a mBL of at least three threads. Multiple linear regression (R2 = 0.229) showed that implants in patients with poor periodontal maintenance and implants placed in periodontally compromised patients were significantly associated with greater mBL (P < .005). Female gender and follow-up time were also associated with greater mBL. CONCLUSIONS: Limited long-term mBL was associated with machined-surface implants. Regular periodontal maintenance visits every 3 to 6 months, especially in periodontally compromised patients, have to be considered paramount to maintain peri-implant bone levels over the long term.

Prevalence of peri-implant diseases. A cross-sectional study based on a private practice environment.

AIM: To determine the prevalence of peri-implant diseases in private practice patients enrolled in a periodontal maintenance programme. MATERIAL AND METHODS: A cross-sectional study was carried out in patients with dental implants attending the dental clinic to comply with a periodontal maintenance programme between January and June 2010. Implants with at least 1 year of loading time (range: 1-18 years) were included. A patient-based prevalence analysis of peri-implant diseases was carried out. Additionally, implants were classified into the following categories: healthy, clinically stable, mucositis and peri-implantitis. RESULTS: A total of 245 patients (964 dental implants) were analysed. Implant and patient-based peri-implantitis prevalences were 9.1% [95% confidence interval (95%CI): 7.5-11.1%] and 16.3% [95%CI: 12.2-21.5%] respectively. Mucositis affected 21.6% [95%CI: 19.1-24.5%] of the studied implants and 38.8% [95%CI: 33.3-45.4%] of the patients. CONCLUSIONS: The prevalence of peri-implantitis in private practice patients enrolled in a periodontal maintenance programme was estimated to be between 12% and 22%. Almost 40% of the patients had mucositis. These prevalences are similar to those published in University environment samples.