Implant failure and clinical and radiographic outcomes after surgical treatment of peri-implantitis: A meta-analysis

PURPOSE

To assess the implant failure rate and clinical and radiographic outcomes of implants affected by peri-implantitis that received surgical treatment.

MATERIALS AND METHODS

A systematic search was conducted of three databases (PubMed, Embase and Cochrane Library) to identify studies that examined implant failure and biological outcomes after surgical peri-implantitis treatment, including ≥ 10 patients and reporting on a follow-up period of at least 12 months. Data and risk of bias were assessed qualitatively and quantitively. Surgical modalities were subdivided into reconstructive, non-reconstructive and combined. Meta-analyses were performed for implant failure, marginal bone level and probing pocket depth at 12 and 36 months with the respective subset of available data for each time and endpoint.

RESULTS

A total of 45 studies with 3,463 treated implants were included in the quantitative evaluation. Meta-analyses revealed low implant failure rates of 1.2% (95% confidence interval 0.4%, -2.1%) and 4.2% (95% confidence interval 1.0%, -8.8%) at 12 and 36 months, respectively. No significant difference between the subgroups was observed at 12 months. At 36 months, reconstructive modalities showed a significantly lower implant failure rate (1.0%; 95% confidence interval 0.0%, 5.0%; P = 0.04, χ2(1) = 4.1) compared to non-reconstructive modalities (8.0%; 95% confidence interval 2.0%, 18.0%). The mean probing pocket depth was 3.71 mm (95% confidence interval 3.48, 3.94 mm) at 12 months and 3.63 mm (95% confidence interval 3.02, 4.24 mm) at 36 months. The mean marginal bone loss was 3.31 mm (95% confidence interval 2.89, 3.74 mm) at 12 months and 2.38 mm (95% confidence interval 1.01, 3.74 mm) at 36 months. No significant differences between the modalities were observed for bleeding on probing after either of these time points. Cumulative interventions during supportive therapy were reported in 9% of the studies.

CONCLUSION

Surgical treatment of peri-implantitis results in a low implant failure rate in the short and medium term. No differences were noted between the different interventions with regard to failure rate. Surrogate therapeutic endpoints were improved after treatment, without significant differences between the different modalities. Therapeutic success and/or disease resolution and cumulative interventions during supportive therapy are seldom reported in the literature, but limited long-term outcomes are documented consistently.

Titanium particles in peri-implantitis: distribution, pathogenesis and prospects

Peri-implantitis is one of the most important biological complications in the field of oral implantology. Identifying the causative factors of peri-implant inflammation and osteolysis is crucial for the disease's prevention and treatment. The underlying risk factors and detailed pathogenesis of peri-implantitis remain to be elucidated. Titanium-based implants as the most widely used implant inevitably release titanium particles into the surrounding tissue. Notably, the concentration of titanium particles increases significantly at peri-implantitis sites, suggesting titanium particles as a potential risk factor for the condition. Previous studies have indicated that titanium particles can induce peripheral osteolysis and foster the development of aseptic osteoarthritis in orthopedic joint replacement. However, it remains unconfirmed whether this phenomenon also triggers inflammation and bone resorption in peri-implant tissues. This review summarizes the distribution of titanium particles around the implant, the potential roles in peri-implantitis and the prevalent prevention strategies, which expects to provide new directions for the study of the pathogenesis and treatment of peri-implantitis.

How does diabetes mellitus impact on the prognosis of dental implants?

DATA SOURCES

Web of Science, Embase, PubMed and Cochrane Library databases were searched for publications up to August 2021.

STUDY SELECTION

The study noted clear inclusion and exclusion criteria. Search terms were provided; only observational studies were considered.

DATA EXTRACTION AND SYNTHESIS

A total of 122 studies were identified through the search strategy. Following deduplication, two reviewers conducted the screening.

RESULTS

A total of 21 observational studies were included, involving cohort, case-control, and cross-sectional study designs. A meta-analysis identified increased risk of peri-implantitis in patients with diabetes mellitus and in smokers when compared to non-diabetic subjects and non-smokers. No significant association was found between poor plaque control or periodontal history and peri-implantitis.

CONCLUSIONS

Patients with diabetes mellitus appear to have a higher risk of peri-implantitis.

Implants Placed with the All-On-4 Technique: A Radiographic Retrospective Study on 156 Implants with a 5- to 14-Year Follow-up

The aim of this retrospective study was to evaluate the performance of implants placed with the All-on-4 technique after a mean time in function of 9 years. A total of 34 patients with 156 implants were selected for this study: 18 patients underwent tooth extraction on the day of implant placement (Group D), and 16 patients were already edentulous (Group E). A periapical radiograph was taken at a mean follow-up of 9 years (range: 5 to 14 years). Success and survival rates and the prevalence of peri-implantitis were calculated. Statistical analysis was used to assess comparisons between groups. After a mean follow-up of 9 years, the cumulative survival rate was 97.4% and the success rate was 77.4%. The difference between the initial and final radiographs resulted in a mean marginal bone loss (MBL) of 1.3 ± 1.06 mm (range: 0.1 to 5.3 mm). No differences were seen between Groups D and E. Peri-implantitis affected 15 implants (9.6%) in 9 patients (26.5%). This study shows that the All-on-4 technique is a reliable treatment method for both edentulous patients and patients requiring tooth extractions, with results maintained over a long follow-up period. The present MBL results are similar to those around implants in other rehabilitation types.

Lack of keratinized mucosa increases peri-implantitis risk

DESIGN

A systematic appraisal and statistical aggregation of primary studies in humans.

DATA SOURCES

The researchers utilized PubMed (Medline) and Scopus databases as the primary data sources for this study. They performed a comprehensive literature search based on free keywords and Medical Subject Heading (MeSH) terms to enhance the search accuracy. The database search was concluded on November 13, 2022. Furthermore, a meticulous examination of the references cited in the selected studies was conducted to identify additional relevant articles that could be incorporated into the analysis.

STUDY SELECTION

The systematic review focused on partially or fully edentulous patients receiving dental implants and aimed to determine if the lack of keratinized mucosa at the implant site increased the risk of peri-implantitis compared to patients with adequate keratinized mucosa. Human studies with a minimum of 100 implants, cross-sectional, cohort, or case-control designs, and a follow-up period of at least one year were included. Studies lacking a clear case definition or information on peri-implantitis and those that did not investigate keratinized mucosa as a risk indicator were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently utilized a systematic review screening website (Rayyan, Qatar Computing Research Institute, Qatar Foundation) to select potential articles, and conflicts were resolved through discussion or consultation with a third reviewer. The data extraction process involved recording information from the included articles, such as study design, patient and implant numbers, prosthesis type (fixed or removable), follow-up duration, peri-implantitis case definition, prevalence at patient and implant levels, keratinized mucosa cutoff value, odds ratio (OR) of peri-implantitis considering keratinized mucosa, and conclusions on the potential effect of keratinized mucosa from each study. The Newcastle Ottawa scale (NOS) and a modified version of NOS were used, respectively, to assess the quality of cohort and cross-sectional studies. Studies scoring below 6 out of 9 points were classified as low quality. For the meta-analysis, the relationship between peri-implantitis and keratinized mucosa was evaluated using the odds ratio (OR) and standard error (SE). Heterogeneity was assessed through the Chi2 test and I2 index, determining whether a random-effects or fixed-effects model should be applied. Subgroup and cluster analyses were conducted based on specific criteria, and forest plots and funnel plots were generated to visualize results and identify potential study bias. Sensitivity analysis was performed to verify the robustness of the meta-analysis, with statistical significance set at p < 0.05. The Review Manager (RevMan) software facilitated data analysis. The GRADE rating system was used to determine the level of evidence, considering factors such as bias risk, imprecision, inconsistency, indirectness, and publication bias. The certainty of the evidence was evaluated based on the overall outcomes of analyzed subgroups.

RESULTS

Twenty-two primary studies were identified, and a meta-analysis was conducted on 16 cross-sectional studies. The prevalence of peri-implantitis ranged from 6.68% to 62.3% at the patient level and from 4.5% to 58.1% at the implant level. The overall analysis revealed a significant association between the lack of keratinized mucosa and a higher prevalence of peri-implantitis (OR = 2.78, 95% CI 2.07-3.74, p < 0.00001). Subgroup analyses with a consistent case definition of peri-implantitis (MBL ≥ 2 mm) showed similar results (OR = 1.96, 95% CI 1.41-2.73, p < 0.0001). Studies focusing on fixed prostheses only demonstrated that the lack of keratinized mucosa was associated with an increased prevalence of peri-implantitis (OR = 2.82, 95% CI 1.85-4.28, p < 0.00001). Among patients under regular implant maintenance, the absence of keratinized mucosa significantly raised the occurrence of peri-implantitis (OR = 2.08, 95% CI 1.41-3.08, p = 0.0002). Studies adjusting for other variables also confirmed a higher risk of peri-implantitis with inadequate keratinized mucosa (OR = 3.68, 95% CI 2.32-5.82, p = 0.007). Although some publication bias was observed, the certainty of evidence based on the GRADE system was judged to be "moderate."

CONCLUSIONS

The lack of keratinized mucosa increased the risk of peri-implantitis, emphasizing the need to consider it during dental implant placement. Inadequate data on patient-specific factors and the predominance of cross-sectional studies influenced the evidence quality (i.e., moderate). Future studies with consistent methodologies shall confirm these findings and identify additional risk indicators to improve implant dentistry practices.

Implants in GBR-Augmented Sites in Patients Treated for Generalized Aggressive Periodontitis: A 10- to 20-Year Prospective Case Series

The aim of this case series was to evaluate implants inserted in bone after guided bone regeneration (GBR). Fourteen patients with generalized aggressive periodontitis (GAP) who had lost one or two maxillary teeth in the incisor or premolar region were enrolled in the study. Due to bone resorption, the lateral width and vertical height of the bone were insufficient for implant placement. GBR was carried out in a staged approach using titanium-reinforced e-PTFE (expanded polytetrafluoroethylene) membranes. No bone grafts or bone substitute materials were used. After 6 to 8 months, turned-surface implants (n = 47) were inserted in augmented and nonaugmented bone sites and prosthetically treated with single crowns. All patients were examined during a 3- to 6-month recall schedule over a 10- to 20-year period, and clinical and radiographic examinations were performed. GBR yielded mean vertical and lateral bone gains of 4.5 and 7.0 mm, respectively. The implant survival rate was 100%, mucositis was present in 28.8% of sites, and peri-implantitis was not found. The annual bone loss at tooth sites was significantly higher than at implant sites in augmented bone (0.5% vs 0.2%, respectively; P = .000), and the adjacent teeth had significantly higher annual bone loss (0.8%; P = .000). Thus, severely periodontally compromised patients can be managed successfully in the long-term with the described clinical protocol.

Nonsurgical Management of Peri-implant Bone Loss Induced by Residual Cement: Retrospective Analysis of Six Cases

This report presents six consecutive cases of peri-implantitis associated with residual methacrylate cement. The cases responded to cement removal and disinfection procedures. Six patients, each presenting one methacrylate cement-retained implant restoration and showing peri-implant inflammation and bone loss, were treated. All the cases were negative for bleeding on probing after 6 weeks, and this was maintained at 1 year of follow-up from nonsurgical therapy and crown refixation with alternative and resorbable cement. The treatment effectively solved the inflammation and led to complete restoration ad integrum, as evaluated clinically and radiographically, after 1 year.

Effectiveness of Periapical Radiography Versus Cone Beam Computed Tomography with Different Kilovoltage Settings in the Detection of Chemically Created Peri-implant Bone Defects: An In Vitro Study

PURPOSE

To determine the effectiveness of cone beam computed tomography (CBCT) images obtained with different kilovoltage settings compared with intraoral periapical photostimulable storage phosphor (PSP) plate images in the detection of chemically created peri-implant defects utilizing a bovine rib bone model in vitro.

MATERIALS AND METHODS

After placing 80 implants in bovine ribs, peri-implant circumferential bone defects of different sizes were created with 70% perchloric acid. CBCT images (3D Accuitomo 170) were acquired at 90 and 75 kVp, and intraoral periapical images were acquired using a PSP system (Carestream KODAK, CS 7600). Using a 5-point Likert scale, two oral and maxillofacial radiologists (OMR) and two oral and maxillofacial surgeons (OMS) evaluated the likelihood of a bone defect being absent or present. The kappa statistic was used to compare observer agreement, and area under the curve values were compared using analysis of variance and the post hoc Tukey test. Significance was set at P ≤ .05.

RESULTS

PSP reliability ranged from discordance to slight for small defects and fair to moderate for larger defects. For CBCT, OMRs had good agreement for defects using 90 kVp, and slight to fair using 75 kVp. Agreement for OMS observations was fair for 75 kVp, and varied from slight to good for 90 kVp. Small lesions were detected more effectively by CBCT than by PSP, and larger lesions were detected more effectively by CBCT at 90 kVp than by CBCT at 75 kVp or by PSP.

CONCLUSION

CBCT imaging at 90 kVp was associated with a significantly higher rate of detection of both small and large chemically simulated bone defects than PSP or CBCT at 75 kVp. CBCT imaging at 75 kVp proved better than PSP for the detection of small defects.