Re-osseointegration of Dental Implants After Periimplantitis Treatments: A Systematic Review

Effect of Air Polishing on the Treatment of Peri-Implant Diseases: A Systematic Review and Meta-Analysis

Peri-implant diseases have become one of the notable biological complications of postrehabilitation with implant-supported restorations. Effective modalities for decontamination of biofilm deposits around implant surfaces are critical for resolution of the inflammation. Air polishing is one of the recommended clinical methods for treating peri-implant diseases. This systematic review assessed clinical evidence on efficacy of using air polishing technology for the management of peri-implant diseases, including peri-implant mucositis and peri-implantitis. Four electronic databases from January 1990 to December 2022 were searched to identify the relative human randomized clinical trials that applied air polishing for nonsurgical and surgical treatment of peri-implant mucositis and peri-implantitis. Twelve articles were selected. For treating peri-implant mucositis, air polishing showed a comparable effect to ultrasonic scaling in the reduction of bleeding on probing (BOP) and probing pocket depth (PPD). The nonsurgical approach of air polishing in treating peri-implantitis varied in the reduction of BOP, PPD, and clinical attachment level (CAL) in evaluated studies. Air polishing in the surgical treatment of peri-implantitis was comparable to mechanical cleaning, implantoplasty, and the use of Ti-brush, in regards to the significant reduction of BOP, PPD, and CAL, as well as the improvement of the bone level between baseline and follow-ups. The standardized mean difference with a 95% confidence interval of the studied parameters was estimated using the random effect model; however, statistical differences were not detected between air polishing and comparative modalities in the treatment of peri-implantitis. Within the limitations of this review, the application of air polishing did not result in more favorable outcomes in the treatment of peri-implant diseases compared to other modalities.

Efficacy of laser in re-osseointegration of dental implants-a systematic review

Despite their high success rates, peri-implantitis can affect the stability and function of dental implants. Various treatment modalities have been investigated for the treatment of peri-implantitis to achieve re-osseointegration. An electronic literature search was performed supplemented by a manual search to identify studies published until January 2022. Articles that evaluated re-osseointegration in peri-implantitis sites in animal models following laser therapy or antimicrobial photodynamic therapy (aPDT) were included. Case reports, case series, systematic reviews, and letters to the editor were excluded. Risk of bias and GRADE assessment were followed to evaluate the quality of the evidence. Six studies out of 26 articles identified on electronic search were included in this review. The studies included animal studies conducted on canine models. Four out of six studies reported a higher degree of re-osseointegration following treatment of implants with laser therapy. The findings suggest that laser decontamination shows potential in enhancing re-osseointegration, particularly with the Er: YAG laser, which effectively decontaminated implant surfaces. However, conflicting outcomes and limitations in the evidence quality warrant caution in drawing definitive conclusions. Based on the limited available evidence, laser therapy may show a higher degree of re-osseointegration of implants than mechanical debridement.

Rational Designs of Biomaterials for Combating Oral Biofilm Infections

Oral biofilms, which are also known as dental plaque, are the culprit of a wide range of oral diseases and systemic diseases, thus contributing to serious health risks. The manner of how to achieve good control of oral biofilms has been an increasing public concern. Novel antimicrobial biomaterials with highly controllable fabrication and functionalization have been proven to be promising candidates. However, previous reviews have generally emphasized the physicochemical properties, action mode, and application effectiveness of those biomaterials, whereas insufficient attention has been given to the design rationales tailored to different infection types and application scenarios. To offer guidance for better diversification and functionalization of anti-oral-biofilm biomaterials, this review details the up-to-date design rationales in three aspects: the core strategies in combating oral biofilm, as well as the biomaterials with advanced antibiofilm capacity and multiple functions based on the improvement or combination of the abovementioned antimicrobial strategies. Thereafter, insights on the existing challenges and future improvement of biomaterial-assisted oral biofilm treatments are proposed, hoping to provide a theoretical basis and reference for the subsequent design and application of antibiofilm biomaterials.

Peri-implantitis management by resective surgery combined with implantoplasty and Er:YAG laser irradiation, accompanied by free gingival graft: a case report

The optimal method for decontamination of implant surfaces for peri-implantitis treatment remains controversial. In recent years, erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and implantoplasty (IP) (i.e. mechanical modification of the implant) have been reported to be effective in decontaminating implant surfaces during the surgical treatment. Also, a lack of adequate keratinized mucosa (KM) around the implant is known to be associated with more plaque accumulation, tissue inflammation, attachment loss, and mucosal recession, increasing the risk of peri-implantitis. Therefore, free gingival graft (FGG) has been recommended for gaining adequate KM around the implant. However, the necessity of acquiring KM for the treatment of peri-implantitis using FGG remains unclear. In this report, we applied the apically positioned flap (APF) as resective surgery for peri-implantitis treatment in conjunction with IP and Er:YAG laser irradiation to polish/clean the implant surface. Furthermore, FGG was conducted simultaneously to create additional KM, which increased the tissue stability and contributed to the positive results. The two patients were 64 and 63 years old with a history of periodontitis. The removal of granulation tissue and debridement of contaminated implant surfaces were performed with Er:YAG laser irradiation post flap elevation and then modified smooth surfaces mechanically using IP. Er:YAG laser irradiation was also utilized to remove the titanium particles. In addition, we performed FGG to increase the width of KM as a vestibuloplasty. Peri-implant tissue inflammation and progressive bone resorption were not observed, and both patients maintained good oral hygiene conditions until the 1-year follow-up appointment. Bacterial analysis via high-throughput sequencing revealed proportional decreases in bacteria associated with periodontitis (Porphyromonas, Treponema, and Fusobacterium). To the best of our knowledge, this study is the first to describe peri-implantitis management and bacterial change before and after procedures by resective surgery combined with IP and Er:YAG laser irradiation for peri-implantitis treatment, accompanied by FGG for increasing KM around the implants.

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.

Osteogenic and long-term antibacterial properties of Sr/Ag-containing TiO2 microporous coating in vitro and in vivo

Bacterial infection and poor osseointegration are two critical issues that need to be solved for long-term use of titanium implants. As such, Sr/Ag-containing TiO₂ microporous coatings were prepared on a Ti alloy surface in the current study via a single-step microarc oxidation technique. The coatings showed both good cytocompatibility in vitro and biosafety in vivo. Sr/Ag incorporation brought no significant change in the surface micromorphology and physicochemical properties, but endowed the coating with strong osteogenic activity and long-term antibacterial capability in vitro. Furthermore, the osteogenic and antibacterial capability of the coating was also confirmed in vivo. In a rat osseointegration model, new bone formation, implant-bone contact, removal torque and bone mineralization were all significantly increased in the M-Sr/Ag group when compared with those in group M, although they were slightly lower than those in group M-Sr. In a periimplantitis model, no rats suffered infection in the M-Sr/Ag group after 3 months of osseointegration and 5 weeks of bacterial inoculation period, when compared to 100% and 75% infection rates in M and M-Sr groups, respectively. In addition, active bone remodeling and many mesenchymal cells were observed in the M-Sr group, suggesting good bone regeneration potential in Sr-containing coatings in the case of controlled periimplantitis. Overall, the Sr/Ag-containing TiO₂ microporous coating is valuable for preventing periimplantitis and improving implant reosseointegration, and is therefore promising for long-term and high quality use of titanium implants.

Early osseointegration of micro-arc oxidation coated titanium alloy implants containing Ag: a histomorphometric study

BACKGROUND

This study aimed to evaluate bone response to micro-arc oxidation coated titanium alloy implants containing Ag.

METHODS

144 titanium alloy implants were prepared by machine grinding and divided into three treatment groups as following, SLA group: sand-blasting and acid-etched coating; MAO group: micro-arc oxidation without Ag coating; MAO + Ag group: micro-arc oxidation containing Ag coating. Surface characterization of three kind of implants were observed by X-ray diffraction, energy dispersive X-ray spectrometer, scanning electron microscopy, High Resolution Transmission Electron Microscope and roughness analysis. The implants were inserted into dog femurs. 4, 8 and 12 weeks after operation, the bone response to the implant to the bone was evaluated by push-out experiment, histological and fluorescent labeling analysis.

RESULTS

MAO + Ag group consisted of a mixture of anatase and rutile. Ag was found in the form of Ag₂O on the surface. The surface morphology of MAO + Ag group seemed more like a circular crater with upheaved edges and holes than the other two groups. The surface roughness of MAO and MAO + Ag groups were higher than SLA group, but no statistical difference between MAO and MAO + Ag groups. The contact angles in MAO + Ag group was smallest and the surface free energy was the highest among three groups. The maximum push-out strength of MAO and MAO + Ag groups were higher than SLA group at all time point, the value of MAO + Ag group was higher than MAO group at 4 and 8 weeks. Scanning electron microscopy examination for the surface and cross-section of the bone segments and fluorescent labeling analysis showed that the ability of bone formation and osseointegration in MAO + Ag group was higher than that of the other two groups.

CONCLUSION

The micro-arc oxidation combination with Ag coating is an excellent surface modification technique to posse porous surface structure and hydrophilicity on the titanium alloy implants surface and exhibits desirable ability of osseointegration.

A comparison of human dental pulp stem cell activity cultured on sandblasted titanium discs decontaminated with Er:YAG laser and air-powder abrasion: an in vitro study

Decontamination of implant surfaces is important to the treatment of peri-implantitis. Er:YAG laser and air-powder abrasion system are regarded as the most effective means of decontamination of implant surfaces. The aim of this in vitro study was to compare the activity of human dental pulp stem cells (hDPSCs) cultured on decontaminated sandblasted titanium discs using Er:YAG laser irradiation and air-powder abrasion. Forty-five titanium discs were contaminated with Escherichia coli (E. coli) bacteria and fifteen titanium discs served as sterile control groups. Thirty contaminated titanium discs were decontaminated with Er:YAG laser or air-powder abrasion system and fifteen contaminated discs were used as contaminated control group. Afterwards, hDPSCs were seeded on all sixty experimental titanium discs. The effects of two decontamination tools on hDPSCs viability were evaluated by MTT assay. Alkaline phosphatase (ALP) activity assay, quantitative real-time PCR analysis and alizarin red staining method were performed to assess hDPSCs osteogenic differentiation. Scanning microscope electron (SEM) was also used to evaluate the effects of two different decontaminated methods on cellular morphology. Our study showed that decontamination using Er:YAG laser caused maximum cell viability. However, the ALP activity was not different in laser and air-abrasion groups. The significant expression of an osteoblastic marker and stronger Alizarin red staining were observed in laser irradiation groups. In addition, SEM observation indicated that grown cells were more stretched and more filopodia in Er:YAG-treated discs. In the present study, Er:YAG laser and air-powder abrasion improved the activity of the cells cultured on the decontaminated titanium discs. However, in comparison with air-powder abrasion, Er:YAG laser was more effective.

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.

Manganese Oxide Nanozyme-Doped Diatom for Safe and Efficient Treatment of Peri-Implantitis

Peri-implantitis is a major cause of dental implant failure. Bacterial biofilm contamination on the implant induces surrounding bone resorption and soft tissue inflammation, leading to severe deterioration of oral health. However, conventional biofilm removal procedures, such as mechanical decontamination and antiseptic application, are not effective enough to induce reosseointegration on decontaminated implant surfaces. This is due to (1) incomplete decontamination of the biofilm from inaccessible areas and (2) physicochemical alteration of implant surfaces caused by decontamination procedures. Herein, a safe and effective therapeutic approach for peri-implantitis is developed, which involves decontamination of implant-bound biofilms using the kinetic energy of microsized oxygen bubbles generated from the catalytic reaction between hydrogen peroxide (H2O2) and manganese oxide (MnO2) nanozyme sheet-doped silica diatom microparticles (Diatom Microbubbler, DM). Rapidly moving microsized DM particles are able to penetrate narrow spaces between implant screws, exerting just the right amount of force to entirely destroy biofilms without harming the surrounding mucosa or implant surfaces, as opposed to conventional antiseptics such as chlorhexidine or 3% H2O2 when used alone. Consequently, decontamination with DM facilitates successful reosseointegration on the peri-implantitis-affected implant surface. In summary, our new DM-based therapeutic approach will become a promising alternative to resolve clinically challenging aspects of peri-implantitis.

Effects of implant surface mechanical instrumentation methods on peri-implantitis: An in vitro study using a circumferential bone defect model

Background/purpose

Although several mechanical and chemical debridement techniques have been reported for the management of peri-implantitis, there is no consensus on the most effective method at present. This in vitro study aimed to examine the effects of different mechanical instrumentation techniques on the debridement of hard calcified materials, which are present on the implant surface, as well as the effect of the defect morphology.

Materials and methods

From a total of 15 implants, five each were assigned to one of three decontamination groups (Rotary titanium brush [Ti], tricalcium phosphate air powder abrasive treatment [Air], and titanium ultrasonic scaler [US] groups); the exposed hydroxyapatite (HA)-coated portion was divided into three 1-mm sections (coronal, middle, and apical). The residual-HA of each portion was measured using a digital microscope.

Results

The overall percentage of residual HA coating was significantly lower in the US group than in the Ti or Air groups (p < 0.01). The percentage of residual HA in the coronal portion was significantly lower in the Ti and US groups than in the Air group (p < 0.05 and p < 0.01, respectively). The percentage of residual HA in the middle portion was significantly lower in the US group than in the Air group (p < 0.01). The percentage of residual HA in the apical portion was significantly lower in the Ti group than in the Air or US groups (p < 0.01).

Conclusion

Ti and US were more effective for shallow defects, whereas US was more effective for deeper defects.

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.

Microbial Biofilm Decontamination on Dental Implant Surfaces: A Mini Review

Introduction

After insertion into the bone, implants osseointegrate, which is required for their long-term success. However, inflammation and infection around the implants may lead to implant failure leading to peri-implantitis and loss of supporting bone, which may eventually lead to failure of implant. Surface chemistry of the implant and lack of cleanliness on the part of the patient are related to peri-implantitis. The only way to get rid of this infection is decontamination of dental implants.

Objective

This systematic review intended to study decontamination of microbial biofilm methods on titanium implant surfaces used in dentistry.

Methods

The electronic databases Springer Link, Science Direct, and PubMed were explored from their inception until December 2020 to identify relevant studies. Studies included had to evaluate the efficiency of new strategies either to prevent formation of biofilm or to treat matured biofilm on dental implant surfaces.

Results and Discussion

In this systematic review, 17 different groups of decontamination methods were summarized from 116 studies. The decontamination methods included coating materials, mechanical cleaning, laser treatment, photodynamic therapy, air polishing, anodizing treatment, radiation, sonication, thermal treatment, ultrasound treatment, chemical treatment, electrochemical treatment, antimicrobial drugs, argon treatment, and probiotics.

Conclusion

The findings suggest that most of the decontamination methods were effective in preventing the formation of biofilm and in decontaminating established biofilm on dental implants. This narrative review provides a summary of methods for future research in the development of new dental implants and decontamination techniques.

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.

The In Vitro Evaluation of Preosteoblast Migration From 3-D-printed Scaffolds to Decontaminated Smooth and Minimally Rough Titanium Surfaces: A Pilot Study

In vitro evaluations are essential to gaining a better understanding of re-osseointegration, while reducing animal use and the overall costs of peri-implantitis studies. This pilot study evaluated preosteoblast migration from 3-D-printed scaffolds to decontaminated titanium microimplants, creating a system that tries to mimic the bone-implant interface. Smooth (S) and minimally rough (R) titanium microimplants were incubated in Escherichia coli cultures and divided into six groups according to the decontamination protocol applied: EDTA gel (EDTA); chlorhexidine (CHL); chlorhexidine-soaked gauze (GCHL); scaling (SC); titanium brush (TiB); and implantoplasty (IP). Pristine S and R microimplants were used as the controls (C). After the decontamination procedures, the microimplants were inserted in 3-D-printed polyurethane-based scaffolds previously inoculated with preosteoblast cell cultures. Cellular migration was assessed after 24, 72 and 120 hours by ATP quantification. At the 120-hour time point, there was no statistically significant difference between S-C, S-EDTA, S-CHL, S-GCHL and S-SC (p > 0.05), and between R-C, R-EDTA and R-GCHL (p > 0.05). The in vitro model developed in this pilot study successfully demonstrated cell migration on the different decontaminated surfaces. This methodology suggests that on smooth microimplants, EDTA, GCHL, SC and TiB decontamination may have a reduced impact on preosteoblast migration, while on minimally rough microimplants, EDTA and GCHL decontamination affected cell migration the least. However, when selecting a decontamination protocol, the effectiveness of the decontamination per se must also be considered.

Application of Selected Nanomaterials and Ozone in Modern Clinical Dentistry

This review is an attempt to summarize current research on ozone, titanium dioxide (TiO₂), silver (Ag), copper oxide CuO and platinum (Pt) nanoparticles (NPs). These agents can be used in various fields of dentistry such as conservative dentistry, endodontic, prosthetic or dental surgery. Nanotechnology and ozone can facilitate the dentist’s work by providing antimicrobial properties to dental materials or ensuring a decontaminated work area. However, the high potential of these agents for use in medicine should be confirmed in further research due to possible side effects, especially in long duration of observation so that the best way to apply them can be obtained.

Regenerative Surgical Therapy of Peri-implantitis: An Umbrella Review of Answered/Unanswered Questions and Future Perspectives

Purpose: To systemically summarize current knowledge about regeneration of peri-implant defects based on available systematic reviews.

Materials and Methods: A systematic search for review articles published between 2010 and 2020 in four databases was conducted. Only systematic reviews and meta-analyses were included. Based on the available literature, five questions of clinical importance on indication for regenerative approaches, surgical technique, methods of decontamination, outcome of therapy and adjunctive use of biological factors were formulated and answered.

Results: The electronic search resulted in 312 studies, from which 264 studies were published between 2010 and 2020. Finally, 18 systematic reviews and one consensus report were chosen. Data of the included studies were based on 58 to 840 implants. Data on over 4.904 implants were assessed. From the 19 studies that were included, 15 assessed the outcome of regenerative therapy; three, the surgical protocol of regenerative therapy; two, the use of laser in regenerative therapy; and one, the additional use of growth factors in regenerative peri-implant therapy. Three studies assessed more than one topic.

Conclusions: In general, a partial bone fill can be expected in 85% of regenerative procedures. Regeneration leads to a mean of 57% of greater bone fill, compared to open flap surgery only. Defect configuration plays a crucial role in the outcome, whereas the role and extent of benefit of different surgical protocols are still not clear.

Evaluation of osteogenic and antibacterial properties of strontium/silver-containing porous TiO2 coatings prepared by micro-arc oxidation

Ti and Ti alloys are bioinert materials and two frequent problems associated with them are bacterial infection and lack of osteogenic potential for rapid bone integration. To overcome the problems, the present study incorporated strontium (Sr) and silver (Ag) simultaneously into porous TiO₂ coatings through a single-step technique, micro-arc oxidation (MAO). Incorporation of Sr and Ag brought no significant changes to coating micromorphology and physicochemical properties, but endowed TiO₂ coatings with both strong antibacterial activity and osteogenic ability. Antibacterial activity increased with Ag contents in the coatings. When Ag content reached 0.58 wt%, the coating showed both excellent short-term (100.0%) and long-term (77.6%) antibacterial activities. Sr/Ag-containing coatings with 18.23 wt% Sr and 0.58 wt% Ag also presented good cytocompatibility for preosteoblast adhesion and proliferation, and promoted preosteoblast osteogenic differentiation both short-termly and long-termly. However, higher Ag content (1.29 wt%) showed toxic effects to preosteoblasts. In summary, MAO is a simple and effective way to incorporate Sr and Ag into porous TiO₂ coatings and Sr/Ag-containing TiO₂ coating with 18.5 wt% Sr and 0.58 wt% Ag has both good osteogenic activity and strong antibacterial capability short-termly and long-termly. Therefore, such coatings are valuable for clinical application to strengthen osseointegration and long-term high quality use of titanum implants.

A modified surgical approach for hard and soft tissue reconstruction of severe periimplantitis defects: laser-assisted periimplant defect regeneration (LAPIDER)

BACKGROUND

The main problem in periimplantitis is often the combination of severe periimplant bone loss with a contaminated implant surface and an insufficient soft tissue situation. Classic surgical concepts with crestal access to the bony defect and debridement of the surface most often lead to partial defect regeneration and a soft tissue recession. An incision directly above the pathologic bony lesion is contrary to general surgical treatment rules.

AIM

To overcome this problem, a new surgical concept was developed which allows to clean the implant surface, reconstruct the bony defect, and improve soft tissue height and thickness without cutting the papilla complex. This publication presents the innovative regenerative treatment approach for severe periimplantitis defects.

MATERIAL AND METHODS

After diagnosis and non-surgical pre-treatment of a severe periimplantitis lesion, the following treatment protocol was applied: horizontal mucosal incision 5 mm apical to marginal mucosa, supraperiosteal preparation in apical direction, cutting through periosteum at the level of the implant apex, subperiosteal coronal flap elevation, exploration and cleaning of the periimplant defect, thorough debridement of the implant surface with the Er:YAG laser, subperiosteal grafting with connective tissue, grafting of the bony defect with autogenous bone chips from the mandibular ramus, and bilayered suturing of periosteum and mucosa. Implant survival, marginal bone levels, periimplant probing depths, recession, and facial mucosa thickness (PIROP ultrasonic measurement) were evaluated in a pilot case at 1-year follow-up examination.

RESULTS

Inter-proximal, oral, and buccal marginal bone levels increased significantly to the level of the implant shoulder from pre-operative to 1-year follow-up examination. No signs of suppuration or periimplant infection were present. Probing depths and recession decreased significantly, while the facial mucosa thickness improved from pre-operative to final examination.

CONCLUSIONS

Marginal bone levels and soft tissue improvement suggest feasibility for the regeneration of severe periimplant hard and soft tissue deficiencies by this new treatment approach. With the use of this concept, the simultaneous implant surface cleansing and improvement of hard and soft tissue seem to be possible and unfavorable postoperative exposition of titanium surface might be prevented. Comparative studies are planned to quantify the effects of this new surgical protocol.

Reosseointegration after the surgical treatment of induced peri-implantitis: systematic review on current evidence and translation from the animal to the human model

INTRODUCTION

The aim of this study was to review the histologic evidence of reosseointegration and related influencing factors in experimental induced peri-implantitis.

EVIDENCE ACQUISITION

An electronic search was performed on Medline for animal studies that included a histometric evaluation of the amount of regenerated bone in contact with an implant surface. Questions raised in the study focused on the role of implant surfaces, bone regeneration and decontamination treatments in achieving reosseointegration. A detailed electronic search was then conducted on MEDLINE (PubMed) up to July 2017.

EVIDENCE SYNTHESIS

One hundred and one articles were selected as abstract, thirty-seven articles assessed as full-text and sixteen finally included in the study. Reported measurements of reosseointegration varied significantly in the study, from 0 to 3.37 mm. There is histological evidence that reosseointegration can occur after treatment of ligature-induced peri-implantitis. However regenerated bone in contact with bone is generally restricted to the most apical portion of the peri-implant defect.

CONCLUSIONS

Animal studies of induced peri-implantitis seem to indicate that rough surfaces can enhance reosseointegration as compared to smooth surfaces. With regard to bone regeneration techniques and materials, submerged healing and barrier membranes have shown a positive effect on reosseointegration. No evidence exists, however, about the specific role of different bone substitutes and their ability to improve bone formation. Growth factors have been shown to improve reosseointegration in animal models, though additional study is required to confirm the data. Several decontamination treatments have been shown to promote reosseointegration compared to control; however no specific procedure has proven superior to others in achieving reosseointegration.

Electrochemical Disinfection of Dental Implants Experimentally Contaminated with Microorganisms as a Model for Periimplantitis

Despite several methods having been described for disinfecting implants affected by periimplantitis, none of these are universally effective and may even alter surfaces and mechanical properties of implants. Boron-doped diamond (BDD) electrodes were fabricated from niobium wires and assembled as a single instrument for implant cleaning. Chemo-mechanical debridement and air abrasion were used as control methods. Different mono-species biofilms, formed by bacteria and yeasts, were allowed to develop in rich medium at 37 °C for three days. In addition, natural multi-species biofilms were treated. Implants were placed in silicone, polyurethane foam and bovine ribs for simulating different clinical conditions. Following treatment, the implants were rolled on blood agar plates, which were subsequently incubated at 37 °C and microbial growth was analyzed. Complete electrochemical disinfection of implant surfaces was achieved with a maximum treatment time of 20 min for Candida albicans, Candida dubliniensis, Enterococcus faecalis, Roseomonas mucosa, Staphylococcus epidermidis and Streptococcus sanguinis, while in case of spore-forming Bacillus pumilus and Bacillus subtilis, a number of colonies appeared after BDD electrode treatment indicating an incomplete disinfection. Independent of the species tested, complete disinfection was never achieved when conventional techniques were used. During treatment with BDD electrodes, only minor changes in temperature and pH value were observed. The instrument used here requires optimization so that higher charge quantities can be applied in shorter treatment times.

Influence of In-Situ Electrochemical Oxidation on Implant Surface and Colonizing Microorganisms Evaluated by Scanning Electron Microscopy

Peri-implantitis is a worldwide increasing health problem, caused by infection of tissue and bone around an implant by biofilm-forming microorganisms. Effects of peri-implantitis treatment using mechanical debridement, air particle abrasion and electrochemical disinfection on implant surface integrity were compared. Dental implants covered with bacterial biofilm were cleaned using mechanical debridement and air particle abrasion. In addition, implants were disinfected using a novel electrochemical technique based on an array of boron-doped diamond (BDD) coated electrodes. Following treatment and preparation, the implants were inspected by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical debridement led to changes in surface topography destroying the manufacturer's medium-rough surface by scratch formation. Air particle abrasion led to accumulation of the abrasive used on the implant surface. With both treatment options, appearance of bacteria and yeasts was not affected. In contrast, electrochemical disinfection did not cause alterations of the implant surface but resulted in distorted microbial cells. Electrochemical disinfection of implant surfaces using BDD electrodes may constitute a promising treatment option for cleaning dental implant surfaces without negatively affecting materials and surface properties.

Peri-implantitis at implants with different diameters: a pilot study in dogs

Aim

To evaluate the progression of an induced peri-implantitis at implants with different diameters and the outcome of a corrective surgical debridement.

Methods

Three months after the extraction of the mandibular premolars and first molars in six dogs, non-submerged narrow implants (3.3 mm in diameter) or standard implants (3.8 mm and 4.1 mm) were installed in the molar regions, bilaterally. After 3 months, peri-implantitis lesions were induced with ligatures and plaque accumulation for 3 months. Plaque accumulation was allowed for a further month after ligatures removal. A surgical mechanical decontamination of the surfaces was subsequently performed using gauzes soaked in saline and irrigation. Five months after, biopsies were retrieved and histological slides prepared. X-rays were taken at treatment and 5 months after.

Results

Fourth months after peri-implantitis induction, 2.2 ± 1.0 mm at the standard implants and 3.2 ± 0.4 mm at the narrow implants were observed. Five months after treatment, a mean gain of marginal bone of 0.5 ± 0.6 mm was obtained at the standard implants and of 0.9 ± 0.4 at the narrow implants (p = 0.249). The vertical and horizontal defects were found partially closed. At the histological analysis, the coronal level of osseointegration after 5 months of healing was at 2.1 ± 0.8 mm at the standard implants, and 2.8 ± 0.3 mm at narrow implants (p = 0.116).

Conclusions

In conclusion, the narrow implants showed a tendency of a faster progression of the induced peri-implantitis compared to standard implants. The implant diameter did not influence the outcome of a surgical treatment of an induced peri-implantitis.

The Effect of Er,Cr:YSGG and Diode Laser Applications on Dental Implant Surfaces Contaminated with Acinetobacter Baumannii and Pseudomonas Aeruginosa

Treatment of peri-implantitis through several implant surface decontamination techniques have been reported, however, some of them can negatively alter the implant surface or enhance more bacterial resistance. The aim of this in vitro study was to evaluate implant surface decontamination by means of Er,Cr:YSGG and diode lasers. Fifty micro-textured (MTX) dental implants were contaminated with Acinetobacter baumannii (n = 25) and with Pseudomonas aeruginosa (n = 25). All implants were then divided into five groups for the decontamination procedure. In group I (GI), decontamination was done with an Er,Cr:YSGG laser (2780 nm), while in group II (GII) decontamination was performed using photodynamic therapy (a 650 nm diode laser). In Group III (GIII) decontamination was performed with photodynamic therapy (an 808 nm diode laser), and in group IV (GIV) decontamination was performed with 0.12% chlorhexidine. Group V (GV) was the control group with no decontamination. After decontamination, colony forming units (CFU) were counted and implants were prepared for SEM analysis. A significant difference (p < 0.001) was observed for GI compared to the other groups, and also for GIV compared to both GII and GIII. The Er,Cr:YSGG laser (GI) showed the best results in decontaminating the implant surface. Chlorhexidine (GIV), proved to be better in decontaminating the implant surface than photodynamic therapy GII and diode laser GIII. No significant difference was found between group GII and GIII. The SEM analysis showed no significant change in the implant surface topography. The results of this study suggest that the Er,Cr:YSGG laser can be considered as an effective technique for reducing bacteria contamination on implant surfaces.

Effects of air abrasive decontamination on titanium surfaces: A systematic review of in vitro studies

BACKGROUND

Air abrasion (AA) is one of the decontamination methods that have demonstrated promising results in treating peri-implant diseases.

PURPOSE

This systematic review aimed at evaluating the in vitro effect of AA on surface change, cleaning efficacy, and biocompatibility of titanium surfaces and at comparing it with other decontamination methods.

MATERIALS AND METHODS

A comprehensive search was conducted up to April 2018 using PubMed, Scopus, and Google Scholar databases to identify studies on the decontamination effect of AA. All types of titanium surfaces, abrasive powders, contaminated surfaces, and measuring methods were included.

RESULTS

Overall, 1502 articles were identified. After screening the titles and abstracts, and carefully reading the full-texts, 48 articles published between 1989 and 2018 were selected. AA was considered almost safe, particularly for the nonmodified surfaces. Nevertheless, harder powders such as sodium bicarbonate tended to damage the surface more than glycine. AA resulted in surface change similar to plastic curettes and Er: YAG lasers. Regarding the cleaning efficacy, there was no significant difference between glycine and sodium bicarbonate, but different mixtures of calcium phosphate, hydroxyapatite, and erythritol were superior to glycine. AA was superior or equal to all other decontamination methods in cleaning. Regarding biocompatibility, AA was more successful in preserving biocompatibility for noncontaminated surfaces compared with contaminated surfaces and when used with erythritol and osteoinductive powders.

CONCLUSIONS

AA can efficiently remove contamination without serious damage to the surface. The main drawback of the AA method seems to be its limitation in restoring the biocompatibility of the surface.

Use of TiBrush for surface decontamination at peri-implantitis sites in dogs: Radiographic and histological outcomes

AIM

The aim of the present study was to evaluate the efficacy on the healing of mechanical decontamination of infected implant surfaces performed with a titanium brush.

METHODS

Mandibular premolars and first molars were extracted bilaterally in six dogs. After 3 months, two unsubmerged implants were installed on both sides of the mandible. Three months later, peri-implantitis was induced with ligatures for 3 months and then removed. After 1 month, surgical mechanical decontamination of the surfaces was performed either with a rotatory titanium brush or gauzes soaked in saline. Five month later, biopsies were retrieved. Evaluations on X-rays taken of the mesiodistal plane and on histological slides prepared in a buccal-lingual plane were performed.

RESULTS

After the induction of peri-implantitis, a mean marginal bone loss of 2.6 ± 0.6 mm and 1.9 ± 1.0 mm was observed in the brush and gauze groups by X-ray, respectively. Five months after treatment, a mean gain of marginal bone of 0.6 mm was obtained in both groups. The mean closures of the vertical and horizontal defects were 0.6 mm and 0.6 mm for the brush group, and 0.8 mm and 0.5 mm for the gauze group, respectively. Histologically, a loss of attachment at the buccal aspect of 2.2 ± 0.9 mm in the brush group and of 2.3 ± 0.5 mm in the gauze group was found. No statistically-significant differences were found after the treatment.

CONCLUSIONS

Mechanical implant surface decontamination performed with a rotatory titanium brush resulted in a marginal bone level gain, yielding a low content of inflammatory infiltrate close to the marginal bone.