Re‐osseointegration following reconstructive surgical therapy of experimental peri‐implantitis. A pre‐clinical in vivo study

The Effect of Implantoplasty on the Fatigue Behavior and Corrosion Resistance in Titanium Dental Implants

Implantoplasty is a technique increasingly used to remove the biofilm that causes peri-implantitis on dental implants. This technique of mechanization of the titanium surface makes it possible to eliminate bacterial colonies, but it can generate variations in the properties of the implant. These variations, especially those in fatigue resistance and electrochemical corrosion behavior, have not been studied much. In this work, fatigue tests were performed on 60 dental implants without implantoplasty, namely 30 in air and 30 in Hank's solution at 37 °C, and 60 with implatoplasty, namely 30 in air and 30 in Hank's solution at 37 °C, using triaxial tension-compression and torsion stresses simulating human chewing. Mechanical tests were performed with a Bionix servo-hydraulic testing machine and fracture surfaces were studied by scanning electron microcopyElectrochemical corrosion tests were performed on 20 dental implants to determine the corrosion potentials and corrosion intensity for control implants and implantoplasty implants. Studies of titanium ion release to the physiological medium were carried out for each type of dental implants by Inductively Coupled-Plasma Mass Spectrometry at different immersion times at 37 °C. The results show a loss of fatigue caused by the implantoplasty of 30%, observing that the nucleation points of the cracks are in the areas of high deformation in the areas of the implant neck where the mechanization produced in the treatment of the implantoplasty causes an exaltation of fatigue cracks. It has been observed that tests performed in Hank's solution reduce the fatigue life due to the incorporation of hydrogen in the titanium causing the formation of hydrides that embrittle the dental implant. Likewise, the implantoplasty causes a reduction of the corrosion resistance with some pitting on the machined surface. Ion release analyses are slightly higher in the implantoplasted samples but do not show statistically significant differences. It has been observed that the physiological environment reduces the fatigue life of the implants due to the penetration of hydrogen into the titanium forming titanium hydrides which embrittle the implant. These results should be taken into account by clinicians to determine the convenience of performing a treatment such as implantoplasty that reduces the mechanical behavior and increases the chemical degradation of the titanium dental implant.

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.

A longitudinal analysis of the impact of nonsurgical and surgical treatment of peri-implantitis upon clinical parameters and implant stability quotient values. A 2-3-year follow-up

OBJECTIVES

In this study, the aim was to investigate the medium- to long-term impact of peri-implantitis treatment upon clinical parameters and implant stability quotient values and to ascertain if magnetic resonance frequency analysis can be used as a diagnostic tool to demonstrate postoperative healing following treatment of peri-implantitis.

MATERIALS AND METHODS

A total of n = 26 patients (n = 86 implants) diagnosed with peri-implantitis were recruited for this prospective cohort study and four different treatment modalities were used. Baseline measurements of a number of clinical parameters as well as implant stability measurements in the form of ISQ were recorded. These measurements were repeated at 6, 12, and 24-36 months following treatment. Analysis of variance was performed for all implants treated as well as separately for each treatment modality. A regression model was also used to determine factors affecting ISQ measurements over time.

RESULTS

Treatment of peri-implantitis resulted in significant improvements of both average PPDs and BOP (p < .0001 and p < .01). ISQ values marginally improved initially for all treatment modalities, but improvement was only maintained for 2-3 years in treatment modalities I (+1.28), III (+1.49), and IV (+2.92). There was a statistically significant negative linear correlation between average PPD and the ISQ values recorded both at baseline (r = -.618, p < 0.0001) and at 2/3 years (r = -.604, p < 0.0001).

CONCLUSION

Over the 2-3-year follow-up period, all four treatment modalities led to improved clinical and radiographic peri-implant parameters but implant stability posttreatment, as indicated by the fact that the recorded ISQ scores remained stable. As a result, use of MRFA as an adjunct to the traditionally used periodontal and radiographic tools for the evaluation of postoperative implant stability following the treatment of peri-implant disease cannot be recommended.

Evaluation of nanoscale versus hybrid micro/nano surface topographies for endosseous implants

We examined the effect of a nanoscale titanium surface topography (D) versus two hybrid micro/nanoscale topographies (B and OS) on adherent mesenchymal stem cells (MSCs) and bone marrow derived macrophages (BMMs) function in cell culture and in vivo. In the in vitro study, compared to OS and B surfaces, D surface induced earlier and greater cell spreading, and earlier and profound mRNA expression of RUNX2, Osterix and BMP2 in MSCs. D surface induced earlier and higher expression of RUNX2 and BMP2 and lower expression of inflammatory genes in implant adherent cells in vivo. Measurement of osteogenesis at implant surfaces showed greater bone-to-implant contact at D versus OS surfaces after 21 days. We explored the cell population on the D and OS implant surfaces 24 h after placement using single-cell RNA sequencing and identified distinct cell clusters including macrophages, neutrophils and B cells. D surface induced lower expression and earlier reduction of inflammatory genes expression in BMMs in vitro. BMMs on D, B and OS surfaces demonstrated a marked increase of BMP2 expression after 1 and 3 days, and this increase was significantly higher on D surface at day 3. Our data implicates a dynamic process that may be influenced by nanotopography at multiple stages of osseointegration including initial immunomodulation, recruitment of MSCs and later osteoblastic differentiation leading to bone matrix production and mineralization. The results suggest that a nanoscale topography (D) favorably modulates adherent macrophage polarization toward anti-inflammatory and regenerative phenotypes and promotes the osteoinductive phenotype of adherent mesenchymal stem cells. STATEMENT OF SIGNIFICANCE: Our manuscript contains original data developed to define effects of a novel nanotopography on the process of osseointegration at the cell and tissue level.  Few studies have compared the effects of a nanoscale surface versus the more typical hybrid micro/nano-scale surfaces used today. We have utilized single-cell RNA sequencing for the first time to identify earliest cell populations on implant surfaces in vivo. We provide data indicating that the nanoscale surface acts upon both osteoprogenitor and immune cell (macrophages) to alter the process of bone formation in a surface-specific manner. This work represents new observations regarding osseointegration and immunomodulation.

Influence of antiresorptive/antiangiogenic therapy on the surgical treatment outcomes of experimentally induced peri-implantitis lesions

OBJECTIVE

To investigate the influence of various antiresorptive and antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions after different surgical treatment approaches.

MATERIALS AND METHODS

Forty-eight albino rats randomly received a dual application of the following medications: (1) amino-bisphosphonate (zoledronate (Zo)) (n = 8), (2) RANKL inhibitor (denosumab (De)) (n = 8), (3) antiangiogenic (bevacizumab (Be)) (n = 8), (4) Zo + Be (n = 8), (5) De + Be (n = 8), or (6) no medication (control (Co)) (n = 8). Ligature-induced peri-implantitis lesions were established at 2 maxillary implants over 16 weeks. Afterward, animals were randomly treated either with open flap debridement (OFD) or reconstructive therapy (RT). Treatment procedures were followed by a 12-week healing period. The histological outcomes included residual defect length (DL); defect width (DW) at the bone crest (BC-DW); 25%, 50%, and 75% of the DL; and areas of inflammatory cell infiltrate (ICT). When present, areas of bone sequester (BS) were assessed considering the animal as a statistical unit.

RESULTS

A total of 21 animals were analyzed (Zo: RT = 3, OFD = 1; De: RT = 3, OFD = 2; Be: OFD = 1; Zo + Be: RT = 2, OFD = 2; Co: RT = 3, OFD = 2). Implant loss rates were comparable among the experimental groups. Except for the 25% and 75% DW values that were significantly higher in the Zo + Be group compared to the Co group (p = 0.04 and p = 0.03, respectively), no significant differences were found among the experimental groups for the DL (lowest-Be: 0.56 mm; highest-Co: 1.05 mm), BC-DW (lowest-De: 0.86 mm, highest-Co: 1.07 mm), 50% DW (lowest-De: 0.86 mm; highest-Be + Zo: 1.29 mm), and ICT (lowest-Be: 0.56 mm2; highest-Be + Zo: 1.65 mm2). All groups, except for the Zo and Be following RT, showed presence of BS.

CONCLUSIONS

The present findings did not reveal a marked effect of various antiresorptive/antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions, regardless of the surgical approach employed (OFD and RT).

CLINICAL RELEVANCE

Resolution of peri-implantitis lesions may not be affected by the investigated antiresorptive/antiangiogenic medications.

Survival analysis of implants after surgical treatment of peri-implantitis based on bone loss severity and surgical technique: a retrospective study

BACKGROUND

Few trials have compared the results of surgical treatment for peri-implantitis based on severity of peri-implantitis and surgical method. This study investigated the survival rate of implants based on type of surgical method used and initial severity of peri-implantitis. Classification of severity was determined based on bone loss rate relative to fixture length.

METHODS

Medical records of patients who underwent peri-implantitis surgery from July 2003 to April 2021 were identified. Classification of peri-implantitis was divided into 3 groups (stage 1: bone loss < 25% (of fixture length), stage 2: 25% < bone loss < 50%, stage 3: bone loss > 50%) and performance of resective or regenerative surgery was investigated. Kaplan-Meier survival curves and Cox hazards proportional models were used to analyze the cumulative survival rate of implants. Median survival time, predicted mean survival time, hazard ratio (HR), and 95% confidence interval (CI) were calculated.

RESULTS

Based on Kaplan-Meier analysis, 89 patients and 227 implants were included, and total median postoperative survival duration was 8.96 years. Cumulative survival rates for stage 1, 2, and 3 were 70.7%, 48.9%, and 21.3%, respectively. The mean survival time for implants in stage 1, 2, and 3 was 9.95 years, 7.96 years, and 5.67 years, respectively, with statistically significant difference (log-rank p-value < 0.001). HRs for stage 2 and stage 3 were 2.25 and 4.59, respectively, with stage 1 as reference. Significant difference was not found in survival time between resective and regenerative surgery groups in any peri-implantitis stage.

CONCLUSIONS

The initial bone loss rate relative to the fixture length significantly correlated with the outcome after peri-implantitis surgery, demonstrating a notable difference in the long-term survival rate. Difference was not found between resective surgery and regenerative surgery in implant survival time. Bone loss rate could be utilized as a reliable diagnostic tool for evaluating prognosis after surgical treatment, regardless of surgical method used.

TRIAL REGISTRATION

Retrospectively registered. (KCT0008225).

Efficacy of surgical methods for peri-implantitis: a systematic review and network meta-analysis

BACKGROUND

Peri-implantitis is the most difficult biological complication associated with dental implants, often requiring surgical treatments in advanced stages. This study compares the effectiveness of different surgical methods for peri-implantitis.

METHODS

Randomized controlled trials (RCTs) of different surgical treatments for peri-implantitis were extracted from EMBASE, Web of Science, Cochrane Library databases, and PubMed systematically. Pairwise comparisons and network meta-analyses (NMA) were conducted to analyze the effect of surgical treatments on probing depth (PD), radiographic bone fill (RBF), mucosal recession (MR), bleeding on probing (BOP), and clinical attachment level (CAL). In addition, risk of bias, quality of evidence, and statistical heterogeneity of the selected studies were evaluated. A total of 13 articles were included in this study, involving open flap debridement (OFD), resective therapy (RT), and augmentative therapy (AT) with and without adjunctive treatments (laser therapy, photodynamic therapy, local antibiotics, phosphoric acid, and ozone therapy).

RESULTS

AT improved RBF and CAL more than OFD, but does not outperform OFD in reducing peri-implant soft-tissue inflammation. AT, OFD and RT did not significantly alter the levels of MR. Addition of ozone therapy improved the effect of AT, but addition of photodynamic therapy did not affect PD reduction and CAL gain significantly. Similarly, adjuvant treatment with phosphoric acid during RT did not significantly change the outcome of BOP.

CONCLUSIONS

Within the limitation of this systematic review and NMA, AT was superior to OFD in improving peri-implantitis outcomes. While adjunct use of ozone therapy may further improve the efficacy of AT, the limited evidence supporting this combination therapy argues for cautionary interpretation of these results.

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.

In-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants

Peri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants' complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.

Bone defect development in experimental canine peri-implantitis models: a systematic review

PURPOSE

To provide a systematic overview of preclinical research regarding bone defect formation around different implant surfaces after ligature-induced peri-implantitis models in dogs. Two focused questions were formulated: 'How much bone loss can be expected after a certain time of ligature induced peri-implantitis?' and 'Do different implant types, dog breeds and study protocols differ in their extent of bone loss?'

MATERIALS AND METHODS

A systematic literature search was conducted on four databases (MEDLINE, Web of Science, EMBASE and Scopus). Observations, which consisted of bone defects measured directly after ligature removal in canine models, were included and analysed. Two approaches were used to analyse the relatively heterogeneous studies that fulfilled the inclusion criteria. First, separate simple linear regressions were calculated for each study and implant surface, for which observations were available across multiple time points. Second, a linear mixed model was specified for the observations at 12 weeks after ligature initiation, and assessing the potential influencing factors on defect depth was explored using lasso regularisation.

RESULTS

Thirty-six studies with a total of 1082 implants were included after. Bone loss was determined at different time points, either with clinical measurements radiographically or histologically. Different implant groups [e.g. turned, sand-blasted-acid-etched (SLA), titanium-plasma-sprayed (TPS) and other rough surfaces] were assessed and described in the studies. A mean incremental defect depth increase of 0.08 mm (SD: -0.01-0.28 mm) per week was observed. After 12 weeks, the defect depths ranged between 0.7 and 5 mm. Based on the current data set, implant surface could not be statistically identified as an essential factor in defect depth after 12 weeks of ligature-induced peri-implantitis.

CONCLUSION

Expectable defect depth after a specific time of ligature-induced peri-implantitis can vary robustly. It is currently impossible to delineate apparent differences in bone loss around different implant surfaces.

Minimal invasiveness in the reconstructive treatment of peri-implantitis defects

Peri-implantitis is a plaque-associated pathologic condition occurring in tissues around dental implants, clinically characterized by increased peri-implant probing pocket depth and progressive loss of supporting bone. Consequently, to arrest further disease progression and to increase the chance to obtain re-osseointegration, surgical reconstructive procedures have been adopted. In particular, following a paradigm gathered from periodontal therapy, recent protocols have underlined the importance of a minimally invasive approach to optimize the outcomes of therapy while minimizing the risks of postoperative complications. The present review summarizes the level of evidence on the surgical reconstructive protocols focusing on the new approaches aiming to minimize surgical trauma and patients' postoperative discomfort, underlining the pros and cons of each treatment modality.

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.

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

AIMS

The purpose was to evaluate the accuracy of bone level assessments using either cone beam computed tomography, intraoral periapical 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, intraoral periapical radiographs and block biopsies from all implants sites were obtained. Marginal bone levels were measured using periapical radiographs, CBCT and histology.

RESULTS

Significant correlations of MBL assessments were observed between the three methods. The measurements in periapical radiographs consistently resulted in an overestimation of the bone level of about 0.3 - 0.4 mm. The agreement between 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.

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.

Efficiency of cold atmospheric plasma, cleaning powders and their combination for biofilm removal on two different titanium implant surfaces

Objectives

Biofilm removal is the decisive factor for the control of peri-implantitis. Cold atmospheric pressure plasma (CAP) can become an effective aid due to its ability to destroy and to inactivate bacterial biofilm residues. This study evaluated the cleaning efficiency of CAP, and air-polishing with glycine (APG) or erythritol (APE) containing powders alone or in combination with CAP (APG + CAP, APE + CAP) on sandblasted/acid etched, and anodised titanium implant surface.

Materials and methods

On respective titanium discs, a 7-day ex vivo human biofilm was grown. Afterwards, the samples were treated with CAP, APG, APE, APG + CAP, and APE + CAP. Sterile and untreated biofilm discs were used for verification. Directly after treatment and after 5 days of incubation in medium at 37 °C, samples were prepared for examination by fluorescence microscopy. The relative biofilm fluorescence was measured for quantitative analyses.

Results

Air-polishing with or without CAP removed biofilms effectively. The combination of air-polishing with CAP showed the best cleaning results compared to single treatments, even on day 5. Immediately after treatment, APE + CAP showed insignificant higher cleansing efficiency than APG + CAP.

Conclusions

CAP supports mechanical cleansing and disinfection to remove and inactivate microbial biofilm on implant surfaces significantly. Here, the type of the powder was not important. The highest cleansing results were obtained on sandblasted/etched surfaces.

Clinical relevance.

Microbial residuals impede wound healing and re-osseointegration after peri-implantitis treatment. Air-polishing treatment removes biofilms very effectively, but not completely. In combination with CAP, microbial free surfaces can be achieved. The tested treatment regime offers an advantage during treatment of peri-implantitis.

Peri-Implantitis: Application of a Protocol for the Regeneration of Deep Osseous Defects. A Retrospective Case Series

Background and aims: Peri-implantitis is a complex pathology, both in its diagnosis and in the identification of etiological causes. Although we have been studying more and more over the years to try to answer the many questions that remain regarding everything that circulates around this disease which affects implants, nothing has yet been taken as an official consensus regarding its surgical treatment. There are still many proposed protocols, each of which has been shown to have comforting results and promising prospects, but no total predictability. The aim of this case series is to assess the clinical outcomes of a mixed protocol for the regeneration of deep osseous defects. Materials and methods: The data and clinical records of 23 patients, with 29 implants affected by peri-implantitis treated surgically in private practice, were analyzed retrospectively. The method used for the surgical treatment was a mixed protocol of mechanical–chemical decontamination and bone regeneration with bovine xenograft. Results: All patients were followed for at least 2 years, averaging 28.9 months (a range of 24–38 months) with a reduction in the probing depth (PD) at one year from the initial 8.14 ± 1.156 mm to 3.72 ± 0.649 mm, and to 4.14 ± 1.093 mm at the final assessment. The differences between assessment time points were always statistically significant. The data regarding bleeding on probing (BoP) and suppuration also showed a statistically significant reduction at the final time point compared to the baseline. Only one patient, at 24 months, still showed BoP, suppuration, and a PD deeper than 5 mm, indicating a recurrence of the disease compared to the initial improvement of the PD (5 mm) at one year. Conclusions: In conclusion, within the limits of this retrospective analysis, it can be affirmed that this combined mechanical–chemical and regenerative decontamination therapy is effective in the treatment of peri-implantitis.

What is the influence of implant surface characteristics and/or implant material on the incidence and progression of peri-implantitis? A systematic literature review

OBJECTIVES

To answer the focused question, 'In animals or patients with dental implants, does implant surface characteristics and/or implant material have an effect on incidence and progression of peri-implantitis?'

MATERIAL AND METHODS

Pre-clinical in vivo experiments on experimental peri-implantitis and clinical trials with any aim and design, and ≥5 years follow-up, where the effect of ≥2 different type of implant material and/or surface characteristics on peri-implantitis incidence or severity, and/or progression, implant survival or losses due to peri-implantitis, and/or marginal bone levels/loss was assessed.

RESULTS

Meta-analyses based on data of pre-clinical experiments, using the ligature induced peri-implantitis model in the dog, indicated that after the spontaneous progression phase implants with a modified surface showed significantly greater radiographic bone loss (effect size 0.44 mm; 95%CI 0.10-0.79; p = .012; 8 publications) and area of infiltrated connective tissue (effect size 0.75 mm² ; 95%CI 0.15-1.34; p = .014; 5 publications) compared to non-modified surfaces. However, in 9 out of the 18 included experiments, reported in 25 publications, no significant differences were shown among the different implant surface types assessed. Clinical and/or radiographic data from 7605 patients with 26,188 implants, reported in 31 publications (20 RCTs, 3 CTs, 4 prospective cohort, and 4 retrospective studies; 12 with follow-up ≥10 years), overall did not show significant differences in the incidence of peri-implantitis, when this was reported or could be inferred, among the various implant surfaces. In general, high survival rates (90-100%) up to 30 years and no clinically relevant differences in marginal bone loss/levels, merely compatible with crestal remodelling, were presented for the various implant types.

CONCLUSION

Pre-clinical in vivo experiments indicate that surface characteristics of modified implants may have a significant negative impact on peri-implantitis progression, while clinical studies do not support the notion that there is a difference in peri-implantitis incidence among the various types of implant surfaces. No assumptions can be made regarding the possible impact of implant material on incidence and/or peri-implantitis progression due to limited information.

Peri-Implantitis Regenerative Therapy: A Review

Simple Summary

Regenerative therapies are one of the options to treat peri-implantitis diseases that cause peri-implant bone loss. This review reports classic and current literature to describe the available knowledge on regenerative peri-implant techniques.

Abstract

The surgical techniques available to clinicians to treat peri-implant diseases can be divided into resective and regenerative. Peri-implant diseases are inflammatory conditions affecting the soft and hard tissues around dental implants. Despite the large number of investigations aimed at identifying the best approach to treat these conditions, there is still no universally recognized protocol to solve these complications successfully and predictably. This review will focus on the regenerative treatment of peri-implant osseous defects in order to provide some evidence that can aid clinicians in the approach to peri-implant disease treatment.

Microbial and host-derived biomarker changes during ligature-induced and spontaneous peri-implantitis in the Beagle dog

OBJECTIVE

To evaluate microbial and host-derived biomarker changes during experimental peri-implantitis in the Beagle dog.

BACKGROUND

Limited data exist on the microbial and biomarker changes during progressive bone loss as result of experimental peri-implantitis.

METHODS

In total, 36 implants (n_dogs  = 6) were assessed over 3 episodes of ligature-induced peri-implantitis followed by a period of spontaneous progression. Implants with hybrid (H) and completely rough (R) surface designs were used. Clinical and radiographic parameters were recorded at 4 timepoints. Peri-implant sulcus fluid was collected from the buccal and lingual aspects of the implants. The presence of 7 bacterial species and 2 host-derived biomarkers was assessed during the study period.

RESULTS

Total bacterial counts were significantly correlated with marginal bone loss (MBL) (r = .21; P = .009). Further, Phorphyromonas gulae (Pg) and Tannerella forsythia (Tf) were commonly correlated with MBL, suppuration (SUP) and the sulcular bleeding index scores (mSBI) (P < .05). Other bacteria were further correlated with SUP, mSBI, and MBL. While the analyzed bacteria dropped, Prevotella intermedia (Pi) further increased during the spontaneous progressive phase (P < .05). Total bacterial load did not differ significantly between H and R implants. Host-derived IL-10 was undetected along the study period. IL-1β positively correlated with probing pocket depth (r = .18; P = .03). During spontaneous progression, H implants displayed statistically significant lower levels of IL-1β (P = .003).

CONCLUSION

Experimental peri-implantitis is associated with an increase in bacterial counts. While Pg and Tf are associated with ligature-induced disease progression, Pi augmented its load during the spontaneous progressive phase. IL-1β is associated with pocket probing depth and influenced by implant surface characteristics during the spontaneous progression phase.