Etiology, pathogenesis and treatment of peri-implantitis: A European perspective.

Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants. It is characterized by inflammation in the peri-implant mucosa and progressive loss of supporting bone. Over the last 30 years, peri-implantitis has become a major disease burden in dentistry. An understanding of the diagnosis, etiology and pathogenesis, epidemiology, and treatment of peri-implantitis must be a central component in undergraduate and postgraduate training programs in dentistry. In view of the strong role of European research in periodontology and implant dentistry, the focus of this review was to address peri-implantitis from a European perspective. One component of the work was to summarize new and reliable data on patients with dental implants to underpin the relevance of peri-implantitis from a population perspective. The nature of the peri-implantitis lesion was evaluated through results presented in preclinical models and evaluations of human biopsy material together with an appraisal of the microbiological characteristics. An overview of strategies and outcomes presented in clinical studies on nonsurgical and surgical treatment of peri-implantitis is discussed with a particular focus on end points of therapy and recommendations presented in the S3 level Clinical Practice Guideline for the prevention and treatment of peri-implant diseases.

Consensus report of the second European Consensus Workshop on Education in Periodontology.

BACKGROUND: The second European Consensus Workshop on Education in Periodontology was commissioned, as a result of the changes in the discipline and the advances in educational methods/technology, to update the 2009 Consensus report of the first European Federation of Periodontology (EFP) Workshop on the same topic that was jointly authored by the Association for Dental Education in Europe. AIM: To identify and propose changes necessary in periodontal education at three levels, namely undergraduate, specialist and continuing professional development (CPD), with respect to learning outcomes, competencies and methods of learning/training and evaluation. METHODS: Four working groups (WGs) considered education in periodontology at the undergraduate, specialist and CPD levels, and education methods. Four commissioned position papers, one per WG, summarized the relevant information. Workshop participants gathered at an in-person consensus meeting to discuss the individual reviews, and this consensus report summarizes the conclusions. RESULTS: The learning outcomes for undergraduate and specialist education in periodontology have been updated, and a proposal for learning outcomes for CPD programmes was made. Learning/teaching/training and evaluation methods were proposed for each level of education, which included face-to-face, virtual and blended learning methods. CONCLUSION: Developments in oral/dental medicine and in contemporary educational technologies have been translated into updated learning outcomes and learning/teaching/ training/evaluation methods relevant to education in periodontology.

Long-term outcomes and prognostic factors of surgical treatment of peri-implantitis - A retrospective study.

AIM: To evaluate long-term outcomes and prognostic factors of non-reconstructive surgical treatment of peri-implantitis. MATERIALS AND METHODS: One hundred forty-nine patients (267 implants) were surgically treated for peri-implantitis and followed for an average of 7.0 (SD: 3.6) years. The primary outcome was implant loss. Additional bone loss and surgical retreatment were secondary outcomes. Patient/implant characteristics, as well as clinical and radiographic parameters collected prior to initial surgery, were evaluated as potential predictors of implant loss. Flexible parametric survival models using restricted cubic spline functions were used; 5- and 10-year predicted rates of implant loss were calculated according to different scenarios. RESULTS: Fifty-three implants (19.9%) in 35 patients (23.5%) were lost during the observation period. Implant loss occurred after a mean period of 4.4 (SD: 3.0) years and was predicted by implant surface characteristics (modified surface; HR 4.5), implant length (HR 0.8 by mm), suppuration at baseline (HR 2.7) and disease severity (baseline bone loss: HR 1.2 by mm). Estimates of 5- and 10-year implant loss ranged from 1% (best prognostic scenario; initial bone loss <40% of implant length, turned implant surface and absence of suppuration on probing (SoP)) to 63% (worst prognostic scenario; initial bone loss ≥60% of implant length, modified implant surface and SoP) and from 3% to 89%, respectively. Surgical retreatment was performed at 65 implants (24.3%) in 36 patients (24.2%) after a mean time period of 4.5 (3.1) years. In all, 59.5% of implants showed additional bone loss, were surgically retreated or lost. CONCLUSIONS: Recurrence of disease is common following surgical treatment of peri-implantitis. The strongest predictor for implant loss was implant surface characteristics. Implant length as well as suppuration and disease severity at baseline were also relevant factors.

Surface decontamination of explanted peri-implantitis-affected implants.

AIM: The present study aimed at evaluating the effect of air-polishing (AP) and a combination of AP and alkaline electrolysed water (AEW) in surface decontamination of explanted peri-implantitis-affected implants. MATERIALS AND METHODS: Twenty-five patients with 34 dental implants scheduled for explantation due to severe peri-implantitis were included. Following implant removal, the apical part of each implant was embedded in acrylic blocks. Implants were randomly allocated to surface decontamination using AP with or without AEW. Four implants were left untreated and used as negative controls. Specimens were analysed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Area of residual bacteria was the primary outcome. RESULTS: SEM analysis revealed that both treatment protocols were effective in biofilm removal and only small proportions of target areas of the implants showed residual bacterial or mineralized deposits. Although differences between the treatment protocols were small, implant thread loci (top/flank/valley), zones of the implant (apical/middle/coronal), implant surface characteristics and gender influenced the results. In addition, EDS analysis showed that zones influenced the atomic% of carbon and calcium and that implant surface characteristics affected the atomic% of titanium. CONCLUSIONS: AP, with or without AEW, is an effective method in removing biofilm from peri-implantitis-affected implants.

Furcation involvement and tooth loss: A registry-based retrospective cohort study.

AIM: This registry-based retrospective cohort study aimed to evaluate the impact of furcation status on the risk for molar loss. MATERIALS AND METHODS: Subjects with and without furcation involvement (FI) in 2010/2011 were identified in a nationwide registry in Sweden (age- and gender-matched sample: 381,450 subjects; 2,374,883 molars). Data on dental and periodontal status were extracted for the subsequent 10-year period. Impact of FI (at baseline or detected during follow-up) on molar loss (i.e., tooth extraction) was evaluated through multilevel logistic regression and survival analyses. RESULTS: FI had a significant impact on molar loss. FI degrees 2 and 3 resulted in adjusted risk ratios of 1.67 (95% confidence interval [CI] 1.63-1.71) and 3.30 (95% CI 3.18-3.43), respectively. Following the first detection of deep FI (degrees 2-3), estimated survival decreased by 4% at 5 years and 8% at 10 years. In addition to FI, endodontic status and probing depth were relevant risk factors for molar loss. CONCLUSIONS: Furcation status had a clinically relevant impact on the risk for molar loss. Following first detection of deep FI, however, the decline in molar survival was minor.

Prevention and treatment of peri-implant diseases-The EFP S3 level clinical practice guideline.

BACKGROUND: The recently published Clinical Practice Guidelines (CPGs) for the treatment of stages I-IV periodontitis provided evidence-based recommendations for treating periodontitis patients, defined according to the 2018 classification. Peri-implant diseases were also re-defined in the 2018 classification. It is well established that both peri-implant mucositis and peri-implantitis are highly prevalent. In addition, peri-implantitis is particularly challenging to manage and is accompanied by significant morbidity. AIM: To develop an S3 level CPG for the prevention and treatment of peri-implant diseases, focusing on the implementation of interdisciplinary approaches required to prevent the development of peri-implant diseases or their recurrence, and to treat/rehabilitate patients with dental implants following the development of peri-implant diseases. MATERIALS AND METHODS: This S3 level CPG was developed by the European Federation of Periodontology, following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, formulation of specific recommendations, and a structured consensus process involving leading experts and a broad base of stakeholders. RESULTS: The S3 level CPG for the prevention and treatment of peri-implant diseases culminated in the recommendation for implementation of various different interventions before, during and after implant placement/loading. Prevention of peri-implant diseases should commence when dental implants are planned, surgically placed and prosthetically loaded. Once the implants are loaded and in function, a supportive peri-implant care programme should be structured, including periodical assessment of peri-implant tissue health. If peri-implant mucositis or peri-implantitis are detected, appropriate treatments for their management must be rendered. CONCLUSION: The present S3 level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to maintain healthy peri-implant tissues, and to manage peri-implant diseases, according to the available evidence at the time of publication.

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.

Relevant domains, core outcome sets and measurements for implant dentistry clinical trials: The Implant Dentistry Core Outcome Set and Measurement (ID-COSM) international consensus report.

AIM: Lack of consistently reported outcomes limits progress in evidence-based implant dentistry and quality of care. The objective of this initiative was to develop a core outcome set (COS) and measurements for implant dentistry clinical trials (ID-COSM). MATERIALS AND METHODS: This Core Outcome Measures in Effectiveness Trials (COMET)-registered international initiative comprised six steps over 24 months: (i) systematic reviews of outcomes reported in the last 10 years; (ii) international patient focus groups; (iii) a Delphi project with a broad range of stakeholders (care providers, clinical researchers, methodologists, patients and industry representatives); (iv) expert group discussions organizing the outcomes in domains using a theoretical framework and identifying the COSs; (v) identification of valid measurement systems to capture the different domains and (vi) final consensus and formal approval involving experts and patients. The methods were modified from the best practice approach following the Outcome Measures in Rheumatoid Arthritis Clinical Trial and COMET manuals. RESULTS: The systematic reviews and patient focus groups identified 754 (665 + 89, respectively) relevant outcome measures. After elimination of redundancies and duplicates, 111 were formally assessed in the Delphi project. By applying pre-specified filters, the Delphi process identified 22 essential outcomes. These were reduced to 13 after aggregating alternative assessments of the same features. The expert committee organized them into four core outcome areas: (i) pathophysiology, (ii) implant/prosthesis lifespan, (iii) life impact and (iv) access to care. In each area, core outcomes were identified to capture both the benefits and harms of therapy. Mandatory outcome domains included assessment of surgical morbidity and complications, peri-implant tissue health status, intervention-related adverse events, complication-free survival and overall patient satisfaction and comfort. Outcomes deemed mandatory in specific circumstances comprised function (mastication, speech, aesthetics and denture retention), quality of life, effort for treatment and maintenance and cost effectiveness. Specialized COSs were identified for bone and soft-tissue augmentation procedures. The validity of measurement instruments ranged from international consensus (peri-implant tissue health status) to early identification of important outcomes (patient-reported outcomes identified by the focus groups). CONCLUSIONS: The ID-COSM initiative reached a consensus on a core set of mandatory outcomes for clinical trials in implant dentistry and/or soft tissue/bone augmentation. Adoption in future protocols and reporting on the respective domain areas by currently ongoing trials will contribute to improving evidence-informed implant dentistry and quality of care.

Early bone healing to implants with different surface characteristics. A pre-clinical in vivo study.

AIM: To examine early bone healing around implants with non-modified and modified surfaces. MATERIAL & METHODS: Four implants with 4 different surface characteristics were installed in one side of the mandible following tooth extraction in 6 dogs. Implants in group A had a non-modified, turned surface, while implants in group B had a surface modification consisting of TiO-blasting and sequential acid-etching in oxalic and hydrofluoric acid. The surface modification of implants in group C was confined to sequential acid-etching in oxalic and hydrofluoric acid and Group D implants had a surface modification of TiO-blasting and acid-etching in hydrofluoric acid. The implant installation procedures were repeated in the opposite side of the mandible 4 weeks later. Biopsies were obtained and prepared for histological analysis 2 weeks later. RESULTS: B and C implants had a higher degree of bone-to-implant contact (BIC%) than A and D implants at 2 weeks of healing. At 6 weeks of healing, the BIC% was higher at B than at A, C and D implants, and higher at C implants than at A implants. The amount of newly formed bone in contact with the implant within the defect area at 2 weeks was higher at implants with modified surfaces (groups B, C and D) than at implants with a non-modified surface (group A). Corresponding results at 6 weeks were superior at B implants. CONCLUSION: It is suggested that an implant surface modification with acid-etching in oxalic and hydrofluoric acid promotes early formation of bone-to-implant contact.

Implants placed in an alveolar ridge with a sloped configuration. A 3-year prospective multicenter study.

AIM: The aim of the present study was to evaluate soft and hard tissue alterations around implants with a modified marginal portion placed in a healed, sloped ridge over 3 years of follow-up. MATERIAL AND METHODS: 65 patients with a single recipient implant site in an alveolar ridge with a lingual-buccal sloped configuration were recruited. Implants with a modified geometry in the marginal portion were installed in such a way that the sloped part of the device was located at the buccal and most apical position of the osteotomy preparation. Crowns were placed 21 weeks after implant placement. Radiologic examinations were performed at implant installation and at 1 and 3 years of follow-up. Bleeding on probing (BoP), probing pocket depth (PPD), and clinical attachment level (CAL; from the crown margin) were recorded at the insertion of the prosthesis and after 1 and 3 years. RESULTS: 57 patients with 57 implant-supported restorations attended the 3 years follow-up examination. The radiographic analysis revealed a mean marginal bone loss of 0.57 mm during the 3 years period. While the average bone loss between 1 and 3 years amounted to 0.30 mm, approximately 50% of the implants showed no bone loss during this period. The results from the clinical examinations showed a CAL gain of 0.11 ± 0.85 mm between baseline and 3 years of follow-up. About 65% of the implants showed no loss of attachment between 1 and 3 years. BoP and PPD ≥5 mm were identified at <10% of implants at the 3 years examination. CONCLUSION: Hard and soft tissues formed around dental implants that were designed to match the morphology of an alveolar ridge with a lingual-buccal sloped configuration remained stable over 3 years.

Decontamination of biofilm-contaminated implant surfaces: An in vitro evaluation.

OBJECTIVES: The aim of the present study was to evaluate the cleaning efficacy of two mechanical and two chemical protocols in the decontamination of implant surfaces. METHODS: In total, 123 commercially available implants were mounted in plastic models mimicking peri-implant circumferential intra-bony defects. A multispecies biofilm was grown on implant surfaces. Mechanical (air-polishing (AP), rotating titanium brush (TiB)) and chemical decontamination (alkaline electrolyzed water, N-acetyl-L-cysteine) protocols were used. Cleaning efficacy in terms of residual biofilm area, chemical surface properties, and bacterial counts were analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and quantitative polymerase chain reaction. RESULTS: Surface decontamination protocols including use of an AP device or a rotating TiB were superior in terms of biofilm removal and in reducing atomic% of Carbon on implant surfaces when compared to methods restricted to wiping with gauze. The use of chemical agents as adjuncts to the mechanical cleaning protocols provided no relevant overall benefit over saline. No treatment modality, however, resulted in complete biofilm removal. CONCLUSION: Air-polishing and rotating TiB were more effective implant surface decontamination protocols than wiping with gauzes. Use of chemical agents did not improve cleaning efficacy.

Relevant domains, core outcome sets and measurements for implant dentistry clinical trials: The Implant Dentistry Core Outcome Set and Measurement (ID-COSM) international consensus report.

AIM: Lack of consistently reported outcomes limits progress in evidence-based implant dentistry and quality of care. The objective of this initiative was to develop a core outcome set (COS) and measurements for implant dentistry clinical trials (ID-COSM). MATERIALS AND METHODS: This Core Outcome Measures in Effectiveness Trials (COMET)-registered international initiative comprised six steps over 24 months: (i) systematic reviews of outcomes reported in the last 10 years; (ii) international patient focus groups; (iii) a Delphi project with a broad range of stakeholders (care providers, clinical researchers, methodologists, patients and industry representatives); (iv) expert group discussions organizing the outcomes in domains using a theoretical framework and identifying the COSs; (v) identification of valid measurement systems to capture the different domains and (vi) final consensus and formal approval involving experts and patients. The methods were modified from the best practice approach following the Outcome Measures in Rheumatoid Arthritis Clinical Trial and COMET manuals. RESULTS: The systematic reviews and patient focus groups identified 754 (665 + 89, respectively) relevant outcome measures. After elimination of redundancies and duplicates, 111 were formally assessed in the Delphi project. By applying pre-specified filters, the Delphi process identified 22 essential outcomes. These were reduced to 13 after aggregating alternative assessments of the same features. The expert committee organized them into four core outcome areas: (i) pathophysiology, (ii) implant/prosthesis lifespan, (iii) life impact and (iv) access to care. In each area, core outcomes were identified to capture both the benefits and harms of therapy. Mandatory outcome domains included assessment of surgical morbidity and complications, peri-implant tissue health status, intervention-related adverse events, complication-free survival and overall patient satisfaction and comfort. Outcomes deemed mandatory in specific circumstances comprised function (mastication, speech, aesthetics and denture retention), quality of life, effort for treatment and maintenance and cost effectiveness. Specialized COSs were identified for bone and soft-tissue augmentation procedures. The validity of measurement instruments ranged from international consensus (peri-implant tissue health status) to early identification of important outcomes (patient-reported outcomes identified by the focus groups). CONCLUSIONS: The ID-COSM initiative reached a consensus on a core set of mandatory outcomes for clinical trials in implant dentistry and/or soft tissue/bone augmentation. Adoption in future protocols and reporting on the respective domain areas by currently ongoing trials will contribute to improving evidence-informed implant dentistry and quality of care.

Influence of epigenetics on periodontitis and peri-implantitis pathogenesis.

Periodontitis is a disease characterized by tooth-associated microbial biofilms that drive chronic inflammation and destruction of periodontal-supporting tissues. In some individuals, disease progression can lead to tooth loss. A similar condition can occur around dental implants in the form of peri-implantitis. The immune response to bacterial challenges is not only influenced by genetic factors, but also by environmental factors. Epigenetics involves the study of gene function independent of changes to the DNA sequence and its associated proteins, and represents a critical link between genetic and environmental factors. Epigenetic modifications have been shown to contribute to the progression of several diseases, including chronic inflammatory diseases like periodontitis and peri-implantitis. This review aims to present the latest findings on epigenetic influences on periodontitis and to discuss potential mechanisms that may influence peri-implantitis, given the paucity of information currently available.

Cellular expression of epigenetic markers and oxidative stress in periodontitis lesions of smokers and non-smokers.

OBJECTIVE: To evaluate differences in the cellular expression of epigenetic markers and oxidative stress in periodontitis lesions between current smokers and non-smokers. BACKGROUND: Tobacco smoking is recognized as one of the major risk factors for periodontitis. However, the mechanisms by which smoking affects the progression of the disease remain to be determined. METHODS: Twenty-five current smokers and 21 non-smokers with generalized severe periodontitis were included. From each patient, one soft tissue biopsy from a periodontitis site was harvested and prepared for histological analysis. The infiltrated connective tissue (ICT) was selected as the region of interest to assess the cellular expression of epigenetic markers and reactive oxygen/nitrogen species (RONS) by immunohistochemistry. RESULTS: Although the ICT of smokers and non-smokers did not differ in size or in the expression of markers for DNA damage or oxidative stress, current smokers presented with significantly lower area proportions and densities of cells positive for the epigenetic markers DNMT1 and AcH3. In addition, periodontitis lesions in current smokers presented with a diminished antimicrobial activity, as indicated by significantly lower densities and area proportions of NOX2- and iNOS-positive cells. CONCLUSIONS: Components of the host response and epigenetic mechanisms in periodontitis lesions in smokers are downregulated as opposed to lesions of non-smokers.

Surgical treatment of experimental peri-implantitis using mechanical and chemical decontamination procedures: A pre-clinical in vivo study.

AIM: To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using mechanical and chemical decontamination methods. MATERIALS AND METHODS: Following extraction of mandibular premolars, four implants with two different surface characteristics (A, moderately rough and B, smooth) were placed in each side of the mandible of six dogs. Experimental peri-implantitis was induced. Surgical treatment of the peri-implantitis sites was carried out using four implant surface decontamination protocols: (i) deposition of a citric acid gel, (ii) mechanical cleaning using a rotating titanium brush, (iii) a combination of the mechanical and chemical procedures, and (iv) saline (control). Clinical and radiographic examinations were performed. Block biopsies were obtained 6 months after therapy and prepared for histological analysis. RESULTS: Irrespective of the treatment group, treatment resulted in 0.63 ± 0.92 and 0.65 ± 0.67 mm radiographic bone gain around implants A and B, respectively. Histological analyses revealed that persisting soft tissue inflammation as assessed using an infiltrated connective tissue (ICT) score was significantly lower at implant type B than at implant type A for all treatment groups. The test decontamination procedures did not demonstrate better results regarding resolution of peri-implantitis lesions, as indicated by the ICT scores, than the control procedure. The control treatment resulted in significantly superior outcomes of resolution of peri-implantitis lesions than the citric acid regimen. CONCLUSIONS: It is concluded that decontamination procedures including citric acid gel or rotating titanium brush did not improve outcomes following surgical treatment of experimental peri-implantitis. Results were, however, influenced by the implant surface characteristics.

Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline.

BACKGROUND: The recently published clinical practice guideline (CPG) for the treatment of periodontitis in stages I-III provided evidence-based recommendations for the treatment of periodontitis patients, defined according to the 2018 classification. Stage IV periodontitis shares the severity and complexity characteristics of stage III periodontitis, but includes the anatomical and functional sequelae of tooth and periodontal attachment loss (tooth flaring and drifting, bite collapse, etc.), which require additional interventions following completion of active periodontal therapy. AIM: To develop an S3 Level CPG for the treatment of stage IV periodontitis, focusing on the implementation of inter-disciplinary treatment approaches required to treat/rehabilitate patients following associated sequelae and tooth loss. MATERIALS AND METHODS: This S3 Level CPG was developed by the European Federation of Periodontology (EFP), following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and a structured consensus process with leading experts and a broad base of stakeholders. RESULTS: The S3 Level CPG for the treatment of stage IV periodontitis culminated in recommendations for different interventions, including orthodontic tooth movement, tooth splinting, occlusal adjustment, tooth- or implant-supported fixed or removable dental prostheses and supportive periodontal care. Prior to treatment planning, it is critically important to undertake a definitive and comprehensive diagnosis and case evaluation, obtain relevant patient information, and engage in frequent re-evaluations during and after treatment. The periodontal component of therapy should follow the CPG for the treatment of periodontitis in stages I-III. CONCLUSIONS: The present S3 Level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat patients with stage IV periodontitis and to maintain a healthy dentition over lifetime, according to the available evidence at the time of publication.

Accuracy of bone-level assessments following reconstructive surgical treatment of experimental peri-implantitis.

AIMS: The purpose of this study was to evaluate the accuracy of bone-level assessments using either cone-beam computed tomography (CBCT), intra-oral peri-apical (PA) radiographs or histology following reconstructive treatment of experimental peri-implantitis. MATERIALS AND METHODS: Six Labrador dogs were used. Experimental peri-implantitis was induced 3 months after implant placement. Surgical treatment of peri-implantitis was performed and peri-implant defects were allocated to one of four treatment categories; no augmentation, bone graft materials with or without a barrier membrane. Six months later, intra-oral PA radiographs and block biopsies from all implants sites were obtained. Marginal bone levels (MBLs) were measured using PA radiographs, CBCT and histology. RESULTS: Significant correlations of MBL assessments were observed between the three methods. The measurements in PA radiographs consistently resulted in an overestimation of the bone level of about 0.3-0.4 mm. The agreement between the methods was not influenced by the use of bone substitute materials in the management of the osseous defects. CONCLUSIONS: Although MBL assessments obtained from PA radiographs showed an overestimation compared to MBL assessments on corresponding CBCT images and histological sections, PA radiographs can be considered a reliable technique for peri-implant bone-level evaluations following reconstructive surgical therapy of experimental peri-implantitis.

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.

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.

Influence of implant geometry and osteotomy design on early bone healing: A pre-clinical in vivo study.

OBJECTIVES: To analyze the early stages of osseointegration around implants with different geometry following installation in sites using different osteotomy protocols. MATERIALS AND METHODS: Two types of implants were installed using regular or modified (reduced diameter) osteotomy protocols in mandibular premolar/molar regions following tooth extraction in six dogs. Three implant site categories were created: Reference (A implant and regular osteotomy), Test-1 (B implant and regular osteotomy), and Test-2 (B implant and modified osteotomy). Implant installation procedures were repeated after 4 and 6 weeks. The insertion torque (ITQ) was measured during implant installation and resonance frequency analysis providing implant stability quotient (ISQ) values was performed following implant installation and once every week during the course of the study. Biopsies were obtained immediately after the 3rd installation procedure and prepared for histological analysis. RESULTS: The modified osteotomy protocol created a higher insertion torque (ITQ). The analysis also revealed a correlation between insertion torque at implant installation and radiographic bone loss after 6 weeks of healing. The decline in ISQ values during healing was more pronounced at Test-2 than other sites. While the degree of bone-to-implant contact (BIC%) in the marginal area was similar in test and reference sites at 6 weeks of healing, Test-2 implants presented with a significantly higher BIC% in the mid and apical areas than Test-1 implants. CONCLUSIONS: It is suggested that placement of implants in undersized osteotomy sites will result in an increased remodeling of the cortical bone during the early healing process.