Retrospective cohort study of 4591 Straumann implants in private practice setting, with up to 10-year follow-up.

BackgroundDue to the risk of peri‐implantitis, following dental implant placement, this study aimed to evaluate risk indicators associated with marginal bone loss from a retrospective open cohort study of 4,591 dental implants, placed in private practice, with 5‐ to 10‐year follow‐up. Furthermore, the prevalence of mucositis and peri‐implantitis among the study cohort was evaluated, comparing strict versus relaxed criteria for bleeding on probing.MethodsPeriapical radiographs were used to evaluate changes in crestal bone level. Peri‐implant soft tissue was evaluated using an ordinal mucosal index in comparison with the conventional binary threshold for bleeding (i.e., present or not). Periodontal probing depth was not evaluated. Linear mixed models were used to evaluate bone level over time, and other risk indicators, at the patient and implant level.ResultsRisk indicators found to have a significant impact on bone level included: autoimmune disease, heavy smoking, bisphosphonate therapy, implant location, diameter and design, and the presence of a bone defect at site of implantation. The prevalence of mucositis at the implant level was 38.6% versus 14.2% at 6 to 7 years, when using strict versus relaxed criteria, respectively. The prevalence of peri‐implantitis after 6 to 7 years was 4.7% and 3.6% when using strict versus relaxed criteria, respectively.ConclusionsThe results of this study identify several risk factors associated with bone loss. Furthermore, the prevalence of mucositis and peri‐implantitis was shown to be lower at both the implant and the patient when using strict versus relaxed criteria based on the assessment of oral health surrounding dental implants.

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Background The present retrospective study was aimed to assess the long‐term clinical performance of dental implants in a cohort study of 4247 patients. Methods A longitudinal observational cohort study was done on all implants performed by a single periodontist from July 1995 to April 2019. The main outcome variables of this study were implant failure and marginal bone level around implants. Results The study participants received a total of 10 871 implants with a mean of 2.56 implants per patient. The cohort was followed‐up to 22.2 years (mean = 4.5 ± 4.2). Among the 4247 patients of the current study, 140 patients (3.3%) experienced a combined total of 178 implant failures. According to life table analysis, at the implant level the cumulative survival rate at 3, 5, 10, and 15 years was 98.9%, 98.5%, 96.8%, and 94.0%, respectively while at patient level was 97.4%, 96.7%, 92.5%, and 86% at 3, 5, 10, and 15 years. Patients with multiple units were at a greater risk for having an implant failure. Baseline bone level was 0.09 ± 0.28 mm while at 8–10 years the mean bone level was 0.49 ± 0.74 mm. The incidence of peri‐implant mucositis at the implant level was 9.4% at 2–3 years, 9.3% at 4–5 years, 12.1% at 6–7 years, and 11.9% at 8–10 years. The incidence of peri‐implantitis was 2%, 2.6%, 3.2%, and 7.1% at 2–3, 4–5, 6–7, and 8–10 years, respectively. Cigarette smoking and diabetes mellitus were positively correlated with implant failure. Conclusions Though the results are promising and encouraging in terms of survival and bone level over time, it is important to emphasize the potential risk factors and consider them prior to dental implant placement.

The purpose of this report is to describe the crestal bone level (CBL) around implants of various designs, describe the peri-implant soft tissue condition, and evaluate the relationship between the two over time. Materials and Methods: This retrospective cohort study reports on 2,060 patients with 4,591 implants evaluated after 3 months; 1, 3, 5, and 7 years; and up to 10 years. Periapical radiographs were used to evaluate changes in CBL. The peri-implant soft tissue was evaluated using a modified Bleeding Index termed the Implant Mucosal Index (IMI) where: 0 = no bleeding; 1 = minimal, single-point bleeding; 2 = moderate, multipoint bleeding; 3 = profuse, multipoint bleeding; and 4 = suppuration. Results: At 3 months, the mean CBL was 0.06 ± 0.22 mm; by 8 to 10 years, it had increased to 0.44 ± 0.81 mm. The median CBL remained stable throughout the study at < 0.1 mm. At 8 to 10 years, 15% of implants exhibited a CBL > 1.02 mm, and 5% exhibited a CBL > 2.28 mm. More than 50% of patients experienced some bleeding, as seen by an IMI ≥ 1 during follow-up. A positive correlation was found between IMI and CBL, as shown by a mean CBL after 4 years of 0.33 mm, 0.71 mm, and 1.52 mm for IMI = 2, 3, and 4, respectively. One exception was between IMI = 0 and IMI = 1, where no significant difference was found and bone loss was minimal. Conclusion: Bone loss, as measured by changes in CBL during the first 10 years of implant life spans, was minimal for most implants. Nevertheless, it is not unusual to observe implants with advanced bone loss. The soft tissue condition is a good indicator of bone loss. Time alone and minimal bleeding did not correlate with bone loss, but care should be taken for implants with profuse bleeding or suppuration. Int

In general, standard platform implants restored with zirconia abutments were successful for the longest periods of observation and are a viable treatment alternative in anterior areas. Some of the studied designs of platform switching implants with zirconia abutments performed well for up to 5 years.

Implants with an anodized surface showed a high long-term survival rate in a daily practice. Longer implants and implants placed in the mandible were associated with greater survival. Immediate loading and tapered design did not affect implant survival. Profuse multipoint bleeding and suppuration on recall were associated with greater bone loss.

This retrospective study with a follow-up period of 4 months to 10 years evaluated survival, success, and complication rates of implants placed using osteotome sinus floor elevation (OSFE) without added bone grafting. A total of 926 implants were placed, including 530 short implants (6 mm to 8.5 mm) and 209 implants in low residual bone height (RBH) (< 5 mm). Bone levels were evaluated at approximately 3 months and at 1, 3, and 5 years, and in some cases up to 10 years after implants were placed. The implant survival rate was 98.3% at the 5-year follow-up. Twelve of the 926 implants failed (6 preprosthetic, 6 postprosthetic). The success rate was 95.4% at a threshold of less than 1 mm of bone loss for combined systems (Straumann; Nobel Biocare). Short implant survival and success rates were statistically comparable to conventional-length implants. Low-RBH implants had a lower but acceptable survival rate of 95.7%. Adverse events were rare, with one case of infection and zero cases of vertigo reported. The findings of this study indicate that implant placement with OSFE without added bone graft is highly successful, even when short implants are used in low RBH.