Porous titanium granules in the treatment of peri-implant osseous defects-a 7-year follow-up study

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.

Emerging factors affecting peri-implant bone metabolism

Implant dentistry has evolved to the point that standard implant osseointegration is predictable. This is attributed in part to the advancements in material sciences that have led toward improvements in implant surface technology and characteristics. Nonetheless, there remain several cases where implant therapy fails (specifically at early time points), most commonly attributed to factors affecting bone metabolism. Among these patients, smokers are known to have impaired bone metabolism and thus be subject to higher risks of early implant failure and/or late complications related to the stability of the peri-implant bone and mucosal tissues. Notably, however, emerging data have unveiled other critical factors affecting osseointegration, namely, those related to the metabolism of bone tissues. The aim of this review is to shed light on the effects of implant-related factors, like implant surface or titanium particle release; surgical-related factors, like osseodensification or implanted biomaterials; various drugs, like selective serotonin reuptake inhibitors, proton pump inhibitors, anti-hypertensives, nonsteroidal anti-inflammatory medication, and statins, and host-related factors, like smoking, diet, and metabolic syndrome on bone metabolism, and aseptic peri-implant bone loss. Despite the infectious nature of peri-implant biological complications, these factors must be surveyed for the effective prevention and management of peri-implantitis.

Selecting biomaterials in the reconstructive therapy of peri-implantitis

Peri-implantitis is a pathogenic inflammatory condition characterized by progressive bone loss and clinical inflammation that may compromise the stability of dental implants. Therapeutic modalities have been advocated to arrest the disorder and to establish peri-implant health. Reconstructive therapy is indicated for bone defects exhibiting contained/angular components. This therapeutic modality is based upon the application of the biological and technical principles of periodontal regeneration. Nonetheless, the comparative efficacy of reconstructive therapy and nonreconstructive modalities remains unclear. Therefore, the aim of this narrative review is to address major clinical concerns regarding the efficacy, effectiveness, and feasibility of using biomaterials in peri-implantitis therapy. In particular, the use of bone grafting materials, barrier membranes, and biologics is comprehensively explored.

The effect of reconstructive techniques as treatment modality for peri-implant osseous defects - a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review is to compare conventional peri-implant flap surgery and reconstructive surgical techniques regarding evidence of remission from peri-implantitis.

MATERIAL AND METHODS

Searches were made among randomized controlled trials evaluating clinical aspects and the changes in marginal bone level before and after surgical treatment of peri-implantitis, with and without bone substitute.

RESULTS

Nine published articles and 442 patients were eligible for inclusion in the study. Reconstructive techniques exhibited a greater extent of defect fill than conventional surgical techniques alone. No significant differences could be found for clinical measures of peri-implant disease (bleeding on probing and reduction of probing depth) from baseline to the 12-month follow-up.

CONCLUSIONS

With regards to the clinical measures of disease, our review shows that there are no differences between open flap debridement and regenerative surgery. From an esthetic standpoint, it may however be that regenerative measures may lead to improvement but further publications with this focus will be necessary to verify this.

Bone tissue regeneration in peri-implantitis: A systematic review of randomized clinical trials

Objectives

The goal of this systematic review was to analyze, in randomized controlled clinical trials (RCTs), regenerative techniques used to treat peri-implantitis (PI).

Methods

Three databases (PubMed/Medline, EMBASE, and On-Line Knowledge Library) were accessed, applying the PICO strategy (Population [P], Intervention [I], Comparison [C], and Outcomes [O]), with the following focused questions: (i) "In patients who received regenerative treatments for peri-implantitis (P), is the regenerative surgical treatment (I) clinically effective and predictable compared to non-regenerative (C) to treat PI (O)?"; and (ii) "In patients who received regenerative treatments for peri-implantitis (P), the regenerative approach (I), compared to non-regenerative (C), significantly increase the prognosis and implant survival rate in the mid- and long-term (O)?" The inclusion criteria were RCTs published in English between 2012 and 2022, with at least a one-year follow-up, which applied regenerative techniques to treat peri-implantitis. Cochrane's collaboration tool for assessing the risk of bias was used.

Main results

Nine articles were included with 404 patients (225 females and 179 males; mean age of 60.44 years). One study evaluated patients after 48 months and another after 88 months. The techniques and devices used were: (i) implantoplasty with Er:YAG laser, (ii) blood concentrate (growth factors), and (iii) EMD, with no statistically significant outcome. Two studies considered the use of titanium granules with a significant increase in radiographic bone identification, whereas regenerative techniques with bone graft (autogenous, alloplastic, and xenograft) were the majority chosen, associated or not, with a collagen membrane. Xenograft had better results radiographically when compared to the autogenous bone graft and presented better results for bone level. There was an overall decrease in bleeding on probing, independent of the control or test group, and a reduction in pocket depth in the groups analyzed. Titanium granules, EMD, Er:YAG laser, and CGF had non-significant results; better results were observed when using bone grafts. The RoB showed a low risk in four studies (44.44%), three with moderate (33.33%), and two with high risk (22.23%).

Conclusion

Surgical regenerative treatment was a predictable option in the management of PI and in improving the clinical parameters of peri-implant tissues in the short term, mainly when using porous titanium granules, alloplastic bone grafts, and xenografts.

Advances in Microgravity Directed Tissue Engineering

Tissue engineering aims to generate functional biological substitutes to repair, sustain, improve, or replace tissue function affected by disease. With the rapid development of space science, the application of simulated microgravity has become an active topic in the field of tissue engineering. There is a growing body of evidence demonstrating that microgravity offers excellent advantages for tissue engineering by modulating cellular morphology, metabolism, secretion, proliferation, and stem cell differentiation. To date, there have been many achievements in constructing bioartificial spheroids, organoids, or tissue analogs with or without scaffolds in vitro under simulated microgravity conditions. Herein, the current status, recent advances, challenges, and prospects of microgravity related to tissue engineering are reviewed. Current simulated-microgravity devices and cutting-edge advances of microgravity for biomaterials-dependent or biomaterials-independent tissue engineering to offer a reference for guiding further exploration of simulated microgravity strategies to produce engineered tissues are summarized and discussed.

A Systematic Review and Meta-Analysis of the Clinical Outcomes for Adjunctive Physical, Chemical, and Biological Treatment of Dental Implants With Peri-Implantitis

The present systematic review evaluated the efficacy of adjunctive therapies in the treatment of peri-implantitis. Studies comparing the outcome of conventional surgical- or nonsurgical mechanical debridement with the addition of an adjunctive therapeutic modality were identified through an electronic and hand search of available literature. Following data extraction, meta-analyses were performed on the primary outcome measures. The effects of the adjunctive therapies on bleeding on probing (13 studies), probing pocket depth (9 studies), and radiographic bone level changes (7 studies) were analyzed to evaluate potential clinical benefit. Heterogeneity was expressed as the I2 index. Fixed and random effect models were demonstrated. The potential benefit of adjunctive therapies over control procedures was evaluated in 18 studies, representing a total of 773 implants. Quality assessment of the studies found only 3 studies to be at a low risk of bias. Meta-analysis among the different additional modalities revealed chemical therapy demonstrating significant effects in probing pocket depth reduction (0.58 mm; 0.44-0.72) and radiographic bone level gain (0.54 mm; 0.16-0.92). No significant improvements in bleeding on probing reduction were found using any adjunctive therapy. Available evidence on the benefits of adjunctive therapy to nonsurgical or surgical mechanical debridement in the treatment of peri-implantitis is limited by low numbers of standardized, controlled studies for individual therapies, heterogeneity between studies, and a variety of outcome measures. The lack of effect of any adjunctive therapy in reducing bleeding on probing questions the overall effectiveness over conventional treatment. The long-term clinical benefit potential of these therapies is not demonstrated.

Peri-implantitis after 40 years: Evidence, mechanisms, and implications: A mapping review

STATEMENT OF PROBLEM

The high prevalence of peri-implantitis (PI) continues to plague patients and the disease is resistant to present treatment regimens. An analysis of the available research is lacking.

PURPOSE

Given the abundance and diversity of research on the topic of PI, the purpose of this mapping review was to synthesize the literature on the prevention of PI, the histopathology of the disease, the state of present therapeutics, and any emerging treatments.

MATERIAL AND METHODS

An extensive literature search was undertaken by using the electronic databases of PubMed, Web of Science, and Science Direct. The keyword strings were peri-implantitis, dental implant, risk assessment, histopathology, prosthesis design, and treatment. The filters applied were time interval from 2000 to 2002; language, English.

RESULTS

A total of 3635 articles were taken from PubMed, 3686 articles from Web of Science, and 2450 articles from Science Direct. After applying the inclusion and exclusion criteria to the titles and abstracts of selected investigations, 214 studies were retrieved.

CONCLUSIONS

The evidence reflects a concerning incidence of PI, without a predictable treatment protocol. An in-depth patient risk assessment considering risk modification, emphasis on surgical and restorative expertise, and strict recall and maintenance is essential to minimize PI.

The efficacy of bone reconstructive therapies in the management of peri-implantitis. A systematic review and meta-analysis

AIM

To evaluate the efficacy of bone reconstructive procedures for the reduction of probing pocket depth (PPD), bleeding on probing (BOP), and suppuration in peri-implantitis-related bone defects at ≥12-month follow-up.

MATERIALS AND METHODS

Three databases were searched for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared bone reconstructive therapies to access flap surgery (AFS) (Focused Question-FQ 1), and RCTs, CCTs, and prospective case series that assessed the efficacy of reconstructive therapies (FQ 2). Meta-analysis was performed for FQ1 when more than three studies were identified, while for FQ2 a network was drawn based on RCTs with common treatment arms.

RESULTS

Seven RCTs were identified for FQ1 while five RCTs and six prospective case series for FQ2. There was no significant difference in PPD change between AFS and reconstructive surgery (-0.387; p = .325) at 12 months. Furthermore, no clear differences in terms of PPD and BOP changes resulted from the different reconstructive therapies included in the network. Only a small percentage of treated cases with any modality achieved peri-implantitis resolution, as defined by different composite outcomes.

CONCLUSIONS

Reconstructive surgery does not offer significant improvements in peri-implant clinical parameters as compared to AFS at 12 months. It was not possible to establish a hierarchy of efficacy among the different biomaterials employed for reconstructive surgery.

Surgical treatment of peri-implantitis with or without adjunctive graft material: a systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis was performed to compare the clinical effect of surgical treatment of peri-implantitis alone or in combination with graft material. Literature searches were conducted up to June 20, 2020. Randomized controlled trials (RCTs) comparing the clinical effects of open flap debridement (OFD) alone and OFD with adjunctive graft materials for the treatment of peri-implantitis were included. Probing depth (PD) changes and marginal bone level (MBL) changes were assessed and expressed as the standardized mean difference (SMD) with 95% confidence interval (CI). Subgroup analyses and sensitivity analyses were conducted. The search yielded 7419 articles, five of which were analysed quantitatively. The adjunctive use of graft materials in OFD did not provide additional PD improvements (SMD 0.46, 95% CI -0.13 to 1.05; P = 0.13), but did yield additional MBL improvements (SMD 1.04, 95% CI 0.71-1.37; P < 0.01). The degradability of the material, number of implants included per patient, and risk of bias did not have significant effects on the results, but the origin of the material may affect the PD improvements. Based on the available evidence, the adjunctive use of graft materials in the surgical treatment of peri-implantitis can significantly improve MBL changes but not PD changes.

Surgical therapy of peri-implantitis

Peri-implantitis is caused by a bacterial challenge; therefore, anti-infective treatment strategies should be employed to manage the disease. As nonsurgical approaches demonstrate limited efficacy in most cases of peri-implantitis, surgical interventions are often required. Treatment outcomes improve following access flap surgery, with or without adjunctive resective and/or augmentation measures. Whereas nonaugmentative therapies (ie, access flap surgery and resective techniques) primarily aim to resolve inflammation and arrest further disease progression, augmentation approaches also seek to regenerate the bony defect and achieve reosseointegration. Currently, limited evidence supports the superiority of augmentative surgical techniques for peri-implantitis treatment over nonaugmentation methods, and human histologic evidence for reosseointegration is sparse. For patients involved in regular postoperative maintenance programs, success of peri-implantitis surgical treatment based on various definitions of success was obtained in over half of the cases after 5-7 years. Despite surgical treatment, cases of further disease progression that required retreatment or led to implant loss were reported.

Efficacy of alternative or adjunctive measures to conventional non-surgical and surgical treatment of peri-implant mucositis and peri-implantitis: a systematic review and meta-analysis

Purpose

To evaluate the efficacy of alternative or adjunctive measures to conventional non-surgical or surgical treatment of peri-implant mucositis and peri-implantitis.

Material and methods

Prospective randomized and nonrandomized controlled studies comparing alternative or adjunctive measures, and reporting on changes in bleeding scores (i.e., bleed0ing index (BI) or bleeding on probing (BOP)), probing depth (PD) values or suppuration (SUPP) were searched.

Results

Peri-implant mucositis: adjunctive use of local antiseptics lead to greater PD reduction (weighted mean difference (WMD) = − 0.23 mm; p = 0.03, respectively), whereas changes in BOP were comparable (WMD = − 5.30%; p = 0.29). Non-surgical treatment of peri-implantitis: alternative measures for biofilm removal and systemic antibiotics yielded higher BOP reduction (WMD = − 28.09%; p = 0.01 and WMD = − 17.35%; p = 0.01, respectively). Surgical non-reconstructive peri-implantitis treatment: WMD in PD amounted to − 1.11 mm favoring adjunctive implantoplasty (p = 0.02). Adjunctive reconstructive measures lead to significantly higher radiographic bone defect fill/reduction (WMD = 56.46%; p = 0.01 and WMD = − 1.47 mm; p = 0.01), PD (− 0.51 mm; p = 0.01) and lower soft-tissue recession (WMD = − 0.63 mm; p = 0.01), while changes in BOP were not significant (WMD = − 11.11%; p = 0.11).

Conclusions

Alternative and adjunctive measures provided no beneficial effect in resolving peri-implant mucositis, while alternative measures were superior in reducing BOP values following non-surgical treatment of peri-implantitis. Adjunctive reconstructive measures were beneficial regarding radiographic bone-defect fill/reduction, PD reduction and lower soft-tissue recession, although they did not improve the resolution of mucosal inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-021-00388-x.

Papilla preservation and minimally invasive surgery for the treatment of peri-implant osseous defects. Clinical and radiographic outcomes of a 5-year retrospective study

OBJECTIVES

Evaluate in a case series the clinical applicability of a regenerative approach for treatment of peri-implant lesions based on papilla preservation flaps (PPF) and minimally invasive surgery (MIST).

MATERIAL AND METHODS

Twenty-one deep peri-implant defects in 21 patients were surgically accessed applying PPF and MIST. The exposed implant surface was decontaminated with the sequential application of mechanical devices and chemical agents. Bone substitutes alone or in combination with a collagen barrier were applied, according to the anatomy of the peri-implant lesion. Clinical and radiographic measurements were collected at baseline, post-surgery, 1 and 5 years.

RESULTS

Primary wound closure was obtained in 100% of the sites and maintained in 90% of the sites at 1 week. Bleeding on probing (BOP) was reduced from 100% at baseline to 28.6% at 1 year and to 42.8% at 5 years. The 1-year pocket reduction was 3.9 ± 1 mm. Residual probing depths (PD) were 4.1 ± 0.9 mm. PD remained stable up to 5 years. The radiographic bone gain was 2.5 ± 1.2 mm (mesial) and 2.5 ± 1.1 (distal) at 1-year and 2.3 ± 1.3 mm (mesial) and 2.6 ± 1.4 mm (distal) at 5 years. The radiographic resolution of the defect was 70.4% ± 19% (mesial) and 70.2% ± 22% (distal) at 1 year and 64.2% ± 21% (mesial) and 67.7% ± 21% (distal) at 5 years. All implants survived up to 5 years. A composite outcome of disease resolution shows consistent 1-year clinical improvements at all the treated sites and substantial 5-year stability.

CONCLUSIONS

PPF and MIST can be successfully applied for the regenerative treatment of peri-implant defects.

Porous Titanium Granules in comparison with Autogenous Bone Graft in Femoral Osseous Defects: A Histomorphometric Study of Bone Regeneration and Osseointegration in Rabbits

Background

The high resorption rate of autogenous bone is a well-documented phenomenon that can lead to insufficient bone quality and quantity in an augmented area. Nonresorbable bone substitutes might perform better than autogenous bone in certain applications if they are able to provide adequate bone formation and graft osseointegration.

Purpose

The aim of this study was to compare the osseous regeneration and graft integration in standardized defects in the rabbit femur treated either with porous titanium granules or autogenous osseous graft.

Materials and Methods

Standardized femoral osseous defects were surgically induced in 45 New Zealand rabbits. Fifteen were treated with porous titanium granules (TIGRAN™-PTG) and membrane (PTGM), 15 with autogenous graft and membrane (AGM), and 15 with membrane alone (CM, control). At six weeks, the defects were assessed histologically and histomorphometrically.

Results

PTGM as compared to AGM presented similar percentages of newly formed bone tissue, but a significantly higher fraction of the region of interest was filled with the bone substitute material. Accordingly, the composite of new bone plus bone substitute material showed significantly higher volumes for PTGM. Yet, the smaller amount of remaining autogenous bone was far better osseointegrated than the titanium granules, which in large regions showed no connection to newly formed bone. Both PTGM and AGM as compared to CM presented higher values of newly formed bone.

Conclusions

This study demonstrated that PTG was similarly effective as autogenous osseous graft in achieving osseous regeneration while PTG performed markedly better in graft volume stability. The resulting higher total percentage of new bone combined with the bone substitute material in PTG could provide a superior foundation for implant placement.