Factors influencing outcomes of surgical therapy of peri-implantitis: A secondary analysis of 1-year results from a randomized clinical study.

AIM: To identify predictors of treatment outcomes following surgical therapy of peri-implantitis. MATERIALS AND METHODS: We performed a secondary analysis of data from a randomized controlled trial (RCT) comparing access flap with or without bone replacement graft. Outcomes at 12 months were probing pocket depth (PPD), bleeding on probing (BOP), soft-tissue recession (REC) and marginal bone level (MBL) change. Multilevel regression analyses were used to identify predictors. We also built an explanatory model for residual signs of inflammation. RESULTS: Baseline PPD was the most relevant predictor, showing positive associations with final PPD, REC and MBL gain, and negative association with probability of pocket closure. Smokers presented higher residual PPD. Absence of keratinized mucosa at baseline increased the probability of BOP but was otherwise not indicative of outcomes. Plaque at 6 weeks was detrimental in terms of residual PPD and BOP. Treatment allocation had an effect on REC. Final BOP was explained by residual PPD ≥6 mm and plaque at more than two sites. CONCLUSIONS: Baseline PPD was the most relevant predictor of the outcomes of surgical therapy of peri-implantitis. Pocket closure should be a primary goal of treatment. Bone replacement grafts may be indicated in aesthetically demanding cases to reduce soft-tissue recession. The importance of smoking cessation and patient-performed plaque control is also underlined.

Efficacy of access flap and pocket elimination procedures in the management of peri-implantitis: A systematic review and meta-analysis.

AIM: To evaluate the efficacy of access flap and pocket elimination procedures in the surgical treatment of peri-implantitis. MATERIALS AND METHODS: Systematic electronic searches (Central/MEDLINE/EMBASE) up to March 2022 were conducted to identify prospective clinical studies evaluating surgical therapy (access flap or pocket elimination procedures) of peri-implantitis. Primary outcome measures were reduction of probing depth (PD) and bleeding on probing (BOP). Risk of bias was evaluated according to study design. Meta-analysis and meta-regression were performed. Results were expressed as standardized mean effect with 95% confidence interval (CI). RESULTS: Evidence from studies directly comparing surgical with non-surgical therapy is lacking. Based on pre-post data originating from 13 prospective patient cohorts, pronounced reductions of PD (standardized mean effect: 2.2 mm; 95% CI 1.8-2.7) and BOP% (27.0; 95% CI 19.8-34.2) as well as marginal bone level gain (0.2 mm; 95% CI -0.0 to 0.5) were observed at evaluation time points ranging from 1 to 5 years. Wide prediction intervals suggested a high degree of heterogeneity. Reduction of mean PD increased by 0.7 mm (95% CI 0.5-0.9) for every millimetre in increase of mean PD at baseline. During the follow-up period ranging from 1 to 5 years, disease recurrence occurred frequently and implant loss was not uncommon. CONCLUSIONS: Access flap and pocket elimination surgery are effective procedures in the management of peri-implantitis, although rates of disease recurrence during 5 years were high. Treatment outcomes were affected by baseline conditions.

Reconstructive surgical therapy of peri-implantitis: A multicenter randomized controlled clinical trial.

OBJECTIVE: To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri-implantitis. METHODS: In this multicenter randomized clinical trial, 138 patients (147 implants) with peri-implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra-oral radiographs, and patient-reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD ≤5 mm at all aspects and (iv) ≤1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient-reported outcomes. RESULTS: During follow-up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted. CONCLUSIONS: Surgical therapy of peri-implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.

Health economic aspects of implant-supported restorative therapy.

BACKGROUND: It is poorly understood how much additional dental care patients consume subsequent to implant therapy. The aim of the present study is to evaluate costs associated with implant-supported restorative therapy during the long-term follow-up. MATERIAL AND METHODS: Costs associated with preventive measures and complication-related procedures over a mean follow-up period of 8.2 years were assessed in patient files of 514 Swedish subjects provided with implant-supported restorative therapy. The restorative therapy and each of the subsequent interventions were assigned a specific cost. Accumulated costs were calculated in three categories: (i) total cost including initial restorative therapy and complication-related interventions, (ii) cost of preventive measures alone, and (iii) cost of complication-related procedures alone. Potential differences by background variables were analyzed using growth curve models. RESULTS: In the whole sample, costs during follow-up ranged from 878 € (95% CI 743; 1,014) for patients with single-tooth restoration(s) to 1,210 € (95% CI 1,091; 1,329) for subjects with full-jaw restoration(s). The majority of costs during follow-up originated from preventive measures (741 € 95% CI 716; 766). Among individuals receiving ≥1 intervention dealing with a complication (n = 253), complication-related costs amounted to 557 € (95% CI 480; 634). For patients with full-jaw restorations, the corresponding amount was 769 € (95% CI 622; 916). Procedures related to peri-implantitis and technical complications resulted in costs similar to each other. Implant loss generated greater costs than any other type of complication. CONCLUSIONS: Costs related to implant-supported restorative therapy during follow-up were associated with the extent of initial therapy. The higher costs during follow-up noted in patients provided with full-jaw restorations were explained by complication-associated procedures. Implant loss was the most costly type of complication.

Performance evaluation of survival regression models in analysing Swedish dental implant complication data with frailty.

The use of inappropriate methods for estimating the effects of covariates in survival data with frailty leads to erroneous conclusions in medical research. This study evaluated the performance of 13 survival regression models in assessing the factors associated with the timing of complications in implant-supported dental restorations in a Swedish cohort. Data were obtained from randomly selected cohort (n = 596) of Swedish patients provided with dental restorations supported in 2003. Patients were evaluated over 9 years of implant loss, peri-implantitis or technical complications. Best Model was identified using goodness, AIC and BIC. The loglikelihood, the AIC and BIC were consistently lower in flexible parametric model with frailty (df = 2) than other models. Adjusted hazard of implant complications was 45% (adjusted Hazard Ratio (aHR) = 1.449; 95% Confidence Interval (CI): 1.153-1.821, p = 0.001) higher among patients with periodontitis. While controlling for other variables, the hazard of implant complications was about 5 times (aHR = 4.641; 95% CI: 2.911-7.401, p<0.001) and 2 times (aHR = 2.338; 95% CI: 1.553-3.519, p<0.001) higher among patients with full- and partial-jaw restorations than those with single crowns. Flexible parametric survival model with frailty are the most suitable for modelling implant complications among the studied patients.

Occurrence and clustering of complications in implant dentistry.

OBJECTIVES: The aim was to evaluate the overall occurrence and potential clustering of biological and technical complications in implant dentistry. MATERIAL AND METHODS: 596 patients provided with implant-supported reconstructions were evaluated for the occurrence of (a) technical complications, (b) peri-implantitis and (c) implant loss during a period of 9 years. Time and type of event were scored, and potential risk factors were explored through parametric modelling of survival and hazards. Clustering of complications was assessed at the patient level, and patient satisfaction was evaluated by questionnaire completed at the 9-year examination. RESULTS: 42% of patients were affected by technical and/or biological complications during the 9-year observation period. Extent of therapy (Hazard Ratio 2.5: patients with partial jaw restorations; HR 3.9: patients with full jaw restorations) and a history of periodontitis (HR 1.6) were identified as risk factors. While technical complications occurred mostly as isolated events, 41% of subjects identified with peri-implantitis and 52% of subjects with implant loss also presented with other complications. The hazard for technical complications and implant loss peaked at 0.7 years and 0.2 years, respectively, while the hazard for peri-implantitis was consistent throughout the observation period. The overall proportion of satisfied patients at 9 years was high (95%), and only minor differences between individuals with and without complications were noted. CONCLUSIONS: Complications following implant-supported restorative therapy were common findings. Extent of therapy and periodontitis were identified as risk factors. While technical complications occurred in an isolated pattern, peri-implantitis and implant loss demonstrated clustering with other types of complications.

Interventions for peri-implantitis and their effects on further bone loss: A retrospective analysis of a registry-based cohort.

OBJECTIVE: The aim of the present study was to assess interventions and their consequences with regard to further bone loss at sites diagnosed with peri-implantitis. MATERIALS AND METHODS: In 2017, records of 70 patients diagnosed with moderate/severe peri-implantitis at ≥1 implant sites 4 years earlier were obtained. Changes of marginal bone levels during the study period assessed on radiographs and predictors of disease progression were identified by Cox regression and mixed linear modelling. Patient files were analysed for professional interventions related to the treatment of peri-implantitis. RESULTS: Mean bone loss (±SD) at implants diagnosed with moderate/severe peri-implantitis was 1.1 ± 2.0 mm over the observation period of 3.3 years. While non-surgical measures including submucosal and/or supra-mucosal cleaning of implants were provided to almost all patients, surgical treatment of peri-implantitis was limited to a subgroup (17 subjects). Surgically treated implant sites demonstrated a mean bone loss of 1.4 ± 2.4 mm prior to surgical intervention, while only minor changes (0.2 ± 1.0 mm) occurred after therapy. Clinical parameters (bleeding/suppuration on probing and probing depth) assessed at diagnosis were statistically significant predictors of disease progression. CONCLUSIONS: Non-surgical procedures were insufficient to prevent further bone loss at implant sites affected by moderate/severe peri-implantitis. Surgical treatment of peri-implantitis markedly diminished the progression of bone loss. Clinical assessments of bleeding on probing and probing depth at diagnosis predicted further bone loss.

Technical complications following implant-supported restorative therapy performed in Sweden.

OBJECTIVE: The aim of this study was to evaluate the occurrence and consequences of technical complications in implant-supported restorative therapy. MATERIAL & METHODS: The occurrence and consequences of technical complications in implant-supported restorative therapy over a mean follow-up period of 5.3 years were assessed based on documentation in files from 2,666 patients. Risk indicators were identified by the use of survival models, considering repeated events. Results were expressed as hazard ratios (HR) including 95% confidence intervals. RESULTS: Technical complications occurred in 24.8% of the patients. Chipping and loss of retention were the most common, affecting 11.0% and 7.9% of supraconstructions, respectively, while implant-related complications (e.g., implant fracture) were rare. More than 50% of the affected patients experienced technical complications more than once and almost all reported complications led to interventions by a dental professional. The extent of the supraconstruction was the strongest risk indicator for both chipping (HR < 0.2) and loss of retention (HR > 3). CONCLUSION: Over a 5-year period, technical complications in implant-supported restorative therapy occurred frequently and their management required professional intervention.