Mechanical non-surgical treatment of peri-implantitis: a single-blinded randomized longitudinal clinical study. II. Microbiological results

The clinical efficacy of powder air-polishing in the non-surgical treatment of peri-implant diseases: A systematic review and meta-analysis

Peri-implant diseases, characterized by inflammatory conditions affecting peri-implant tissues, encompass peri-implant mucositis and peri-implantitis. Peri-implant mucositis is an inflammatory lesion limited to the mucosa around an implant, while peri-implantitis extends from the mucosa to the supporting bone, causing a loss of osseointegration. For non-surgical treatments, we tested the null hypothesis that the presence or absence of air-polishing made no difference. The study focused on randomized controlled trials (RCTs) comparing air-polishing with mechanical or ultrasonic debridement, evaluating outcomes such as bleeding on probing (BOP), probing depth (PD), plaque index/plaque score (PI/PS), clinical attachment level (CAL), bone loss, and mucosal recession (MR). Two independent reviewers conducted data extraction and quality assessments, considering short-term (<6 months) and long-term (≥6 months) follow-up periods. After screening, ten articles were included in the meta-analysis. In nonsurgical peri-implant disease management, air-polishing moderately mitigated short-term PI/PS for peri-implant mucositis and showed a similar improvement in long-term BOP and bone loss for peri-implantitis compared to the control group. The Egger test found no evidence of publication bias except for the long-term PI/PS of peri-implant mucositis. Leave-one-out analysis confirmed the stability of the results. The findings highlight the need for future research with longer-term follow-up and high-quality, multi-center, large-sample RCTs.

Erythritol powder airflow for the treatment of peri-implant mucositis: A randomized controlled clinical trial

OBJECTIVES

Peri-implant mucositis is a biofilm-related, reversible inflammatory disease that can evolve into peri-implantitis if not adequately treated. The aim of the present randomized controlled clinical trial was to evaluate the efficacy of air-abrasive powder as compared to chlorhexidine (CHX) for the treatment of peri-implant mucositis, in terms of clinical and patient-reported outcomes (PROMs) and occurrence of peri-implantitis 12 months after treatment.

METHODS

In the control group, full-mouth calculus and plaque removal was performed with ultrasound and manual devices, and a 1.0% CHX gel was applied; in the test group, supra- and subgingival biofilm removal was performed using erythritol powder with a dedicated nozzle and calculus removal was performed with ultrasonic instruments if needed. Bleeding and plaque indexes, peri-implant probing depth and tissue level were measured at 1 week, and 1, 3, 6 and 12 months after treatment, while PROMs were evaluated up to 7 days after treatment.

RESULTS

Among 80 included implants, 70 were analysed at 12 months follow-up (30 in the test group, 40 in the control group, and 20 subjects). Success rates (implant-level) in terms of bleeding index were significantly different between the test (96.7%) and control group (92.5%); as for PROMs, only taste sensation was significantly better in the test group. The test group was significantly correlated to the smallest changes in peri-implant probing depth between baseline and 3 months.

CONCLUSIONS

The study showed that both treatment strategies are effective. This suggests that the use of air-abrasive powders could be used as an alternative biofilm removal method instead of adjunctive treatments with antiseptics.

Microbiological profile of peri-implantitis: Analyses of peri-implant microbiome

PURPOSE

To characterize the microbiome composition in peri-implant pocket of peri-implantitis and peri-implant sulcus controls using 16S rRNA gene sequencing.

MATERIALS AND METHODS

In this controlled clinical cross-sectional study, 23 subjects with control implants (n = 14) and diseased implants (peri-implantitis, n = 21) were included. The peri-implant pocket/sulcus was sampled and used to extract DNA and amplify the 16S rRNA gene using universal primers targeting the V3-V4 regions. The resulting 16S PCR amplicons were sequenced on Illumina MiSeq, and the sequences were processed using DADA2 and the Human Oral Microbiome Database (HOMD) as references. Alpha and Beta diversity, as well as core microbiome and differential abundance analyses, were performed using the MicrobiomeAnalyst workflow.

RESULTS

There were no significant differences in microbial diversity between control implants and implants with peri-implantitis (Shannon p = 0.82). Overall bacterial community structure assessed through beta diversity analysis was also not significantly different between the two groups (p = 0.18). However, high levels of Gram-negative bacteria were detected in peri-implant pockets compared to the control sulcus. Abundant species in peri-implantitis were Capnocytophaga leadbetteri, Treponema maltophilum, Peptostreptococcus, Neisseria, P. gingivalis, and Porphyromonas endodontali, Lactococcus lactis and Filifactor alocis (p < 0.05). Gram-positive bacteria such as Streptococcus salivaris, Prevotella melaninogenica, L. wadei, and Actinomyces spp. serve were more abundant in peri-implant control sulcus.

CONCLUSIONS

Peri-implant sulcus in control implants harbors predominantly Gram-positive bacteria, whereas pockets of implants with peri-implantitis harbor predominantly Gram-negative bacteria.

Novel Flowchart Guiding the Non-Surgical and Surgical Management of Peri-Implant Complications: A Narrative Review

Peri-implant diseases, such as peri-implant mucositis and peri-implantitis, are induced by dysbiotic microbiota resulting in the inflammatory destruction of peri-implant tissue. Nonetheless, there has yet to be an established protocol for the treatment of these diseases in a predictable manner, although many clinicians and researchers have proposed various treatment modalities for their management. With the increase in the number of reports evaluating the efficacy of various treatment modalities and new materials, the use of multiple decontamination methods to clean infected implant surfaces is recommended; moreover, the use of hard tissue laser and/or air abrasion techniques may prove advantageous in the future. Limited evidence supports additional effects on clinical improvement in antimicrobial administration for treating peri-implantitis. Implantoplasty may be justified for decontaminating the implant surfaces in the supracrestal area. Surgical treatment is employed for advanced peri-implantitis, and appropriate surgical methods, such as resection therapy or combination therapy, should be selected based on bone defect configuration. This review presents recent clinical advances in debridement methods for contaminated implant surfaces and regenerative materials for treating peri-implant bone defects. It also proposes a new flowchart to guide the treatment decisions for peri-implant disease.

Knowledge and attitude of dental students regarding etiology, diagnosis, and treatment of peri-implantitis

OBJECTIVE

The objective of this study was to assess the level of knowledge and attitude of dental students about the etiology, diagnosis, and management of peri-implantitis.

METHODS

An online cross-sectional study that targeted senior undergraduate dental students at the College of Dentistry was conducted. A closed-ended survey consisting of 28 questions was designed. Three sections were created: 1) participants' characteristics; 2) Knowledge of peri-implantitis etiology, risk factors, diagnosis, and complications; 3) The use of antibiotics in peri-implantitis, diagnosis, and treatment methods. SPSS version 22 (IBM Corp.) was used for data analysis. Counts and percentages were calculated for correct answers in each section.

RESULTS

A total of 267 dental students responded to the questionnaire. The majority of the participants (81.6%) were knowledgeable about peri-implantitis being an inflammatory reaction, and a lesser percentage (77.9%) knew that bacterial plaque is an etiologic factor for peri-implant diseases. 82.0% of the participants identified smoking as a risk factor, followed by periodontitis (80.5%). Regarding implant complications, 57.3% of the participants considered implant mobility as a definitive indication for implant removal. More than half of the participants reported using crater-like bone defects surrounding implants to diagnose peri-implantitis. The most commonly used antibiotic was amoxicillin (34.1%), followed by amoxicillin combined with metronidazole (26.9%).

CONCLUSION

Most participants had a basic understanding of the etiology and risk factors of peri-implantitis. On the other hand, more courses addressing peri-implantitis diagnosis are needed.

Thermal Effects of 445-nm Diode Laser Irradiation on Titanium and Ceramic Implants

This study aimed to evaluate temperature changes in titanium and ceramic implants after using a 445-nm diode laser under different in vitro conditions. Titanium (Ti) and ceramic (Zr) dental implants were placed into a bone analog, and an intrabony defect was created at each implant. A 445-nm diode laser was used to irradiate the defects for 30 seconds, noncontact, at 2 W in continuous wave (c.w.) and pulsed mode. The experiment was done at room temperature (21.0 ± 1°C) and in a water bath (37.0 ± 1°C). Two thermocouple probes were used to record real-time temperature changes (°C) at the coronal part of the implant (Tc) and the apex (Ta). The temperature was recorded at time 0 (To) and after 30 seconds of irradiation (Tf). The average temperature change was calculated, and a descriptive analysis was conducted (P < .05). The Ti implant resulted in the highest ΔT values coronally (29.6°C) and apically (6.7°C) using continuous wave at 21°C. The Zr implant increased to 26.4°C coronally and 5.2°C apically. In the water bath, the coronal portion of the Ti and Zr implants rose to 14.2°C and 14.01°C, respectively, using continuous waves. The ΔT values for Ti were 11.9°C coronally and 1.7°C apically when placed in a water bath using pulsed mode. The lowest ΔT occurred on the Zr implant with ΔTc and ΔTa of 4.8°C and 0.78°C, respectively. Under in vitro conditions, the 445-nm diode laser in pulsed mode seems to be safe for use on ceramic implants and should be used with caution on titanium implants.

Antibacterial Evaluation of Zirconia Coated with Plasma-Based Graphene Oxide with Photothermal Properties

The alternative antibacterial treatment photothermal therapy (PTT) significantly affects oral microbiota inactivation. In this work, graphene with photothermal properties was coated on a zirconia surface using atmospheric pressure plasma, and then the antibacterial properties against oral bacteria were evaluated. For the graphene oxide coating on the zirconia specimens, an atmospheric pressure plasma generator (PGS-300, Expantech, Suwon, Republic of Korea) was used, and an Ar/CH₄ gas mixture was coated on a zirconia specimen at a power of 240 W and a rate of 10 L/min. In the physiological property test, the surface properties were evaluated by measuring the surface shape of the zirconia specimen coated with graphene oxide, as well as the chemical composition and contact angle of the surface. In the biological experiment, the degree of adhesion of Streptococcus mutans (S. mutans) and Porphyromonas gingivalis (P. gingivalis) was determined by crystal violet assay and live/dead staining. All statistical analyzes were performed using SPSS 21.0 (SPSS Inc., Chicago, IL, USA). The group in which the zirconia specimen coated with graphene oxide was irradiated with near-infrared rays demonstrated a significant reduction in the adhesion of S. mutans and P. gingivalis compared with the group not irradiated. The oral microbiota inactivation was reduced by the photothermal effect on the zirconia coated with graphene oxide, exhibiting photothermal properties.

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.

Effect of Implantoplasty on Roughness, Fatigue and Corrosion Behavior of Narrow Diameter Dental Implants

Implantoplasty (IP) is used in dental implants with peri-implantitis and aims to remove threads and polish rough surfaces in order to prevent bacterial colonization. As a result of this procedure, implant strength might be compromised. We tested 20 tapered screw-shaped Ti6Al4V dental implants with a simulated bone loss of 50%. Ten implants underwent IP and 10 served as controls. Surface topography (S_a, S_z, S_sk, and S_dr) was analyzed with a confocal optical microscope. Subsequently, a minimum of four series of cyclic loads were applied with a servo-hydraulic mechanical testing machine (5 × 10⁶ cycles at 15 Hz, between a maximal nominal value-starting at 529 N in the IP group and 735 N in the control group-and 10% of that force). We recorded the number of cycles until failure and the type of failure. Implant failure was analyzed by visual inspection and scanning electron microscopy. Open circuit potential and potenctiodynamic tests were carried out with high precision potentiostat using Hank's solution at 37 °C to evaluate the effect of the implantoplasty on the corrosion resistance. Implantoplasty significantly reduced the surface topography values (median) and interquartile range (IQR); S_a from 1.76 (IQR = 0.11) to 0.49 (IQR = 0.16), S_z from 20.98 (IQR = 8.14) to 8.19 (IQR = 4.16), S_sk from 0.01 (IQR = 0.34) to -0.74 (IQR = 0.53) and S_dr from 18.20 (IQR = 2.26) to 2.67 (IQR = 0.87). The fatigue limits of the control and implantoplasty groups were 551 N and 529 N, respectively. The scanning electron micrographs showed fatigue striations indicating fatigue failure. Besides, the fractographic analysis revealed a typical brittle intergranular fracture mechanism. The infinite life range of the dental implants evaluated was largely above the threshold of usual chewing forces. Implantoplasty seems to render a fairly smooth surface and has a limited impact on fatigue resistance. In addition, implantoplasty produces a decrease in the corrosion resistance of the implant. Corrosion current density from 0.019 μA/cm² for as-received to 0.069 μA/cm² in the interface smooth-roughened dental implant. These places between the machining and the rough area of the implant are the most susceptible, with the appearance of pitting.

Shift in the submucosal microbiome of diseased peri-implant sites after non-surgical mechanical debridement treatment

Objectives

The object of this prospective study was to assess the submucosal microbiome shifts in diseased peri-implant sites after non-surgical mechanical debridement therapy.

Materials and methods

Submucosal plaques were collected from 14 healthy implants and 42 diseased implants before and eight weeks after treatment in this prospective study. Mechanical debridement was performed using titanium curettes, followed by irrigation with 0.2% (w/v) chlorhexidine. Subsequently, 16S rRNA gene sequencing was used to analyze the changes in the submucosal microbiome before and after the non-surgical treatment.

Results

Clinical parameters and the submucosal microbiome were statistically comparable before and after mechanical debridement. The Alpha diversity decreased significantly after mechanical debridement. However, the microbial richness varied between the post-treatment and healthy groups. In network analysis, the post-treatment increased the complexity of the network compared to pre-treatment. The relative abundances of some pathogenic species, such as Porphyromonas gingivalis, Tannerella forsythia, Peptostreptococcaceae XIG-6 nodatum, Filifactor alocis, Porphyromonas endodontalis, TM7 sp., and Desulfobulbus sp. HMT 041, decreased significantly following the non-surgical treatment.

Conclusions

Non-surgical treatment for peri-implant diseases using mechanical debridement could provide clinical and microbiological benefits. The microbial community profile tended to shift towards a healthy profile, and submucosal dysbiosis was relieved following mechanical debridement.

Preventing Peri-implantitis: The Quest for a Next Generation of Titanium Dental Implants

Titanium and its alloys are frequently the biomaterial of choice for dental implant applications. Although titanium dental implants have been utilized for decades, there are yet unresolved issues pertaining to implant failure. Dental implant failure can arise either through wear and fatigue of the implant itself or peri-implant disease and subsequent host inflammation. In the present report, we provide a comprehensive review of titanium and its alloys in the context of dental implant material, and how surface properties influence the rate of bacterial colonization and peri-implant disease. Details are provided on the various periodontal pathogens implicated in peri-implantitis, their adhesive behavior, and how this relationship is governed by the implant surface properties. Issues of osteointegration and immunomodulation are also discussed in relation to titanium dental implants. Some impediments in the commercial translation for a novel titanium-based dental implant from "bench to bedside" are discussed. Numerous in vitro studies on novel materials, processing techniques, and methodologies performed on dental implants have been highlighted. The present report review that comprehensively compares the in vitro, in vivo, and clinical studies of titanium and its alloys for dental implants.

Efficacy of Er:YAG laser for the peri-implantitis treatment and microbiological changes: a randomized controlled trial

The aims of this study were to identify the microbiological changes in the periodontal pockets following an Er:YAG laser (ERL) irradiation and mechanical debridement to compare the effectiveness of ERL irradiation to mechanical debridement for peri-implantitis treatment through randomized controlled trials. Twenty-three patients with peri-implantitis lesions were treated in either a test group, ERL set at energy level of 100 mJ/pulse, frequency of 10 Hz, pulse duration was 100 µs, and irradiated by three passages, or a control group, with mechanical debridement using an ultrasonic scaler. An examiner measured the following clinical parameters at different stages (a baseline and at 3- and 6-month post-treatment): probing depth (PD), bleeding on probing (BOP), marginal bone loss (MBL), and anaerobic bacteria counts. Linear regression, with generalized estimation equations, was used to compare the clinical parameters and anaerobic bacterial counts at different stages and between groups. The anaerobic bacterial counts significantly decreased within the control group during the follow-ups. At the 6-month follow-up, both groups showed a significant reduction in PD (test group: mean difference of 0.84 mm; control group: mean difference of 0.41 mm), and the test group showed a significantly higher PD reduction on the buccal site (1.31 mm) compared to that of the control group (0.25 mm). Both ERL and mechanical debridement treatments led to significant improvements in PD. When mechanical debridement therapy was used, significant anaerobic bacterial count reductions were observed. Future treatment of peri-implantitis should involve a combination of both of these therapies.

Does Ultraviolet Radiation Exhibit Antimicrobial Effect against Oral Pathogens Attached on Various Dental Implant Surfaces? A Systematic Review

Background: Dental implant therapy is currently identified as the most effective treatment for edentulous patient. However, peri-implant inflammations were found to be one of the most common complications that leads to the loss and failure of dental implantation. Ultraviolet (UV) radiation has been proposed to enhance bone integration and reduce bacterial attachment. In this study, we aimed to systematically review the current evidence regarding the antimicrobial effect of UV on different dental implant surfaces. Methods: Five databases including PubMed, Scopus, Web of science, VHL, and Cochran Library were searched to retrieve relevant articles. All original reports that examined the effect of the application of UV radiation on dental implants were included in our study. Results: A total of 16 in vitro studies were included in this systematic review. Polymethyl methacrylate UV radiation has induced a significant decrease in bacterial survival in PMMA materials, with an increased effect by modification with 2.5% and 5% TiO₂ nanotubes. UV-C showed a superior effect to UV-A in reducing bacterial attachment and accumulation. UV wavelength of 265 and 285 nm showed powerful bactericidal effects. UV of 365 nm for 24 h had the highest inhibition of bacterial growth in ZnO coated magnesium alloys. In UV-irradiated commercially pure titanium surfaces treated with plasma electrolytic oxidation, silver ion application, heat or alkali had shown significant higher bactericidal effect vs non-irradiated treated surfaces than the treatment with any of them alone. UVC and gamma-ray irradiation increased the hydrophilicity of zirconia surface, compared to the dry heat. Conclusion: UV radiation on Ti surfaces exhibited significant antibacterial effects demonstrated through the reduction in bacterial attachment and biofilm formation with suppression of bacterial cells growth. Combination of UV and treated surfaces with alkali, plasma electrolytic oxidation, silver ion application or heat enhance the overall photocatalytic antimicrobial effect.

The Application of Antimicrobial Photodynamic Therapy (aPDT) in the Treatment of Peri-Implantitis

Background

This literature review evaluates the mechanisms and efficacy of different types of antimicrobial photodynamic therapy (aPDT) for treating peri-implantitis by reviewing existing experimental studies to provide guidance for the clinical application of antibacterial photodynamic therapy (aPDT) in oral implants.

Materials and Methods

From February 2001 to February 2021, we have collected 152 randomized controlled trials of aPDT for peri-implantitis by searching the experimental studies and clinical trials published in PubMed, Embase, Web of Science, and Google Scholar databases via online search. After screening the retrieved literature, we finally selected 10 statistically significant literature for evaluation and review.

Results

Compared with the traditional nonsurgical treatment of peri-implantitis, the aPDT was superior to the traditional mechanical irrigation treatment group in terms of periodontal indexes PD, BOP, PLI, and postoperative effect, and the difference was statistically significant (P < 0.05). Furthermore, the combination of the aPDT and other treatments shows the synergistic antibacterial effect, signifying better clinical effect in many aspects (P < 0.05). In these 10 papers, by comparing the probe depth (PD), bleeding on probing (BOP), synosteosis, and periodontal pathogenic bacteria detection, etc., obtained after treating peri-implantitis by application of the antimicrobial photodynamic therapy, and using the SPSS data analysis software for statistical data processing, we found that the antimicrobial photodynamic therapy combined with other periodontal treatments has a more prominent postoperative effect. Meanwhile, the antibacterial photodynamic therapy with targeted action of photosensitizer has strong specificity to some bacteria, while the synthetic photosensitize for antibacterial photodynamic therapy can show good inactivation effect on broad-spectrum periodontal anaerobes without side effect.

Conclusion

The experimental studies and clinical data of antibacterial photodynamic therapy for treating peri-implantitis show a good postoperative treatment effect. In addition, it did not develop resistance due to the use of antibiotic drugs. Owing to multiple advantages from combining antibacterial photodynamic therapy and other treatments, it is applicable for clinical treatment.

Airflow for initial nonsurgical treatment of peri-implantitis: A systematic review and meta-analysis

BACKGROUND

Nonsurgical treatment of peri-implantitis may help in reducing microbial load and inflammatory parameters. The potential clinical benefits of using different treatment approaches, in the initial nonsurgical treatment phase, particularly the airflow, are still not clear. The aim of this systematic review and meta-analyses was to evaluate the outcomes of nonsurgical treatment of peri-implantitis using airflow method in terms of changes in periodontal parameters, peri-implant marginal bone level, postoperative pain/discomfort, and patient satisfaction.

METHODS

Electronic databases were searched to identify randomized controlled trials (RCTs) that compared airflow with mechanical debridement using ultrasonic/curettes. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. Data were analyzed using a statistical software program.

RESULTS

A total of 316 studies were identified, of which, five RCTs with 288 dental implants in 174 participants were included. Overall meta-analysis showed more reduction in probing pocket depths at 1-3 months (mean difference [MD] -0.23; 95% confidence interval [CI] -0.50-0.05; p = 0.10) and 6 months (MD -0.04; 95% CI -0.34 to 0.27; p = 0.80) in favor of airflow, but the difference was not statistically significant. The use of airflow was associated with significant reduction in bleeding on probing and increase in peri-implant mucosal recession. The differences in plaque score, peri-implant marginal bone level changes, and patient reported outcomes between airflow and mechanical debridement were not statistically significant.

CONCLUSIONS

The short-term clinical and radiographic outcomes following nonsurgical treatment of peri-implantitis using airflow or mechanical debridement were comparable. The airflow has short-term positive effects on reducing bleeding on probing. Further evidence from RCTs are still required to substantiate the current findings.

Peri-Implant Diseases

Osseointegrated dental implants have become an increasingly popular modality of treatment for the replacement of absent or lost teeth because of its high rates of long-term survival when used to support various types of dental prostheses. However, complications and implant failure can still occur and are considered by many clinicians as a major obstacle for implant treatment. Biological complications mainly refer to inflammatory conditions of the soft tissues and bone surrounding implants and their restorative components, which are induced by the accumulation of bacterial biofilm. Two clinical varieties may be distinguished: peri-implant mucositis and peri-implantitis. Peri-implant mucositis is a reversible, plaque-induced inflammatory lesion confined to the peri-implant soft tissue unit, whereas peri-implantitis is an extension of peri-implant mucositis to involve the bone supporting the implant. Diagnosing and managing these biological complications is of utmost importance for the implant surgeon and dental practitioner. This review encompasses the etiology, diagnostic aspects, prevention, and management of biological complications.

Efficacy of an Er:YAG laser in the decontamination of dental implant surfaces: An in vitro study

BACKGROUND

Emergence of peri-implant diseases led to the development of various methods for implant surface decontamination. This study was designed to compare the efficacy of biofilm removal from implant-like titanium surfaces by an erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, titanium brush, and carbon fiber curet.

METHODS

Eight study subjects were recruited. A custom mouth appliance that held eight sandblasted and acid-etched titanium discs was fabricated for each subject. Subjects were asked to wear this appliance for 72 hours to allow for biofilm development. After retrieval, discs were removed and randomized to one of four treatment groups. The discs were stained with a two-component nucleic acid dye kit, and the residual biofilm was visualized under fluorescence microscopy. Quantification of residual biofilm was performed using an image analysis software and expressed as the percentage surface area.

RESULTS

Fifty-nine titanium discs were randomized to the four treatment groups. The percentage of titanium disc area covered by residual biofilm was 74.0% ± 21.6%, 32.8% ± 24.0%, 11.8% ± 10.3%, and 20.1% ± 19.2% in the control, Er:YAG, titanium brush and carbon fiber curet groups, respectively (mean ± SD). The biofilm-covered area significantly decreased in each of the three treatment groups compared with control (P < 0.008). Comparisons between treatment groups did not reveal statistical significance.

CONCLUSIONS

Er:YAG laser treatment is an effective method for reducing the bacterial biofilm on titanium discs. However, on a threadless titanium surface, Er:YAG laser does not exhibit a significantly greater efficacy in biofilm removal than commonly used titanium brushes or carbon fiber curets.

Assessment of Titanium Level in Submucosal Plaque Around Healthy Implants and Implants with Peri-implantitis: A Clinical Study

Background

The present study focused on assessing the level of titanium in submucosal plaque in the peri-implant area with peri-implantitis in comparison to healthy implants.

Methodology

Sixty patients with titanium dental implants were recruited. The degree of titanium in submucosal plaque around peri-implantitis and healthy implants was estimated using inductively coupled plasma mass spectrometry.

Results

The mean ± standard deviation probing depth in Group I was 3.12 ± 1.1 and in Group II was 7.2 ± 2.5; gingival index was 0.64 ± 0.3 and 1.64 ± 0.8 in Group I and Group II, respectively. The plaque index was 0.82 ± 0.2 in Group I and 1.5 ± 0.6 in Group II. The mean plaque mass in Group I was 24.1 ± 3.8 ng/ul and 49.3 ± 6.4 ng/ul in Group II. The mean titanium level in Group I was 0.08 ± 0.02 μg and in Group II was 0.91 ± 0.04 μg. A highly significant difference between both groups was found (P < 0.05).

Conclusion

There was a significantly higher titanium level in submucosal plaque around dental implants with signs of peri-implantitis as compared to healthy dental implants.

Effect of implantoplasty on the elastic limit of dental implants of different diameters

BACKGROUND

Implantoplasty reduces both implant diameter and the thickness of its walls, subsequently reducing the ability of the implant to resist fracture in response to functional load. In combination with an increase in the crown-implant ratio due to bone loss, this could increase the lever effect, which in presence of high masticatory forces or parafunctional habits, could lead to complications such as fracture of the implant or loosening of the prosthetic screw.

OBJECTIVES

To determine the elastic limits of internal connection, dental implants of different designs and diameters after an implantoplasty.

MATERIALS AND METHODS

This in vitro study included 315 tapered internal connection titanium dental implants, the threads of which were removed with an industrial milling machine-for standardized implantoplasty (IMP1; n = 105)-or with the conventional approach-manually, using high-speed burs (IMP2; n = 105). The remaining 105 implants were used as controls. The final implant diameters were recorded. The quality of the newly polished surfaces was assessed by scanning electron microscopy. All implants were subjected to a mechanical pressure resistance test. A Tukey's test for multiple comparisons was used to detect differences in the elastic limit and final implant diameters between the implant groups.

RESULTS

There were statistically significant differences in the elastic limit between the IMP1, IMP2, and control groups (p < 0.05). Furthermore, the implant diameter was significantly smaller in the IMP1 and IMP2 groups (p < 0.05). Scanning electron microscopy revealed smooth implant surfaces in the IMP1 and IMP2 groups, with some titanium particles visible in the IMP1 group.

CONCLUSIONS

Implantoplasty significantly decreased the elastic limit of internal connection titanium dental implants, especially in those with a smaller diameter (3-3.5 mm).

Risk factors, diagnosis and treatment of peri-implantitis: A cross-cultural comparison of U.S. and European periodontists' considerations

BACKGROUND

Peri-implantitis (PI) is a growing concern in the dental community worldwide. The study aimed to compare U.S. vs. European periodontists' considerations of risk factors, diagnostic criteria, and management of PI.

MATERIALS AND METHODS

393 periodontists from the U.S. and 100 periodontists from Europe (Germany, Greece, Netherlands) responded to anonymous surveys electronically or by mail.

RESULTS

Compared to U.S. periodontists, European respondents were younger, more likely to be female and placed fewer implants per month (9.12 vs. 13.90;p = 0.003). Poor oral hygiene, history of periodontitis, and smoking were considered as very important risk factors by both groups (rated >4 on 5-point scale). European periodontists rated poor oral hygiene (4.64 vs. 4.45;p = 0.005) and history of periodontitis (4.36 vs. 4.10;p = 0.006) as more important and implant surface (2.91 vs. 3.18;p = 0.023), occlusion (2.80 vs. 3.75;p<0.001) and presence of keratinized tissue (3.27 vs. 3.77;p<0.001) as less important than did U.S. periodontists. Both groups rated clinical probing, radiographic bone loss, and presence of bleeding and suppuration as rather important diagnostic criteria. They rated implant exposure/mucosal recession as relatively less important with U.S. periodontists giving higher importance ratings than European periodontists (3.99 vs. 3.54;p = 0.001). Both groups nearly always used patient education, plaque control and mechanical debridement when treating PI. U.S. periodontists were more likely to use antibiotics (3.88 vs. 3.07;p<0.001), lasers (2.11 vs. 1.68;p = 0.005), allograft (3.39 vs. 2.14;p<0.001) and regenerative approaches (3.57 vs. 2.56;p<0.001), but less likely to use resective surgery (3.09 vs. 3.53;p<0.001) than European periodontists.

CONCLUSIONS

U.S. and European periodontists' considerations concerning risk factors, diagnosis and management of PI were evidence-based. Identified differences between the two groups can inform future educational efforts. This article is protected by copyright. All rights reserved.

Antimicrobial TiO2 nanocomposite coatings for surfaces, dental and orthopaedic implants

Engineering of self-disinfecting surfaces to constrain the spread of SARS-CoV-2 is a challenging task for the scientific community because the human coronavirus spreads through respiratory droplets. Titania (TiO₂) nanocomposite antimicrobial coatings is one of the ideal remedies to disinfect pathogens (virus, bacteria, fungi) from common surfaces under light illumination. The photocatalytic disinfection efficiency of recent TiO₂ nanocomposite antimicrobial coatings for surfaces, dental and orthopaedic implants are emphasized in this review. Mostly, inorganic metals (e.g. copper (Cu), silver (Ag), manganese (Mn), etc), non-metals (e.g. fluorine (F), calcium (Ca), phosphorus (P)) and two-dimensional materials (e.g. MXenes, MOF, graphdiyne) were incorporated with TiO₂ to regulate the charge transfer mechanism, surface porosity, crystallinity, and the microbial disinfection efficiency. The antimicrobial activity of TiO₂ coatings was evaluated against the most crucial pathogenic microbes such as Escherichia coli, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Legionella pneumophila, Staphylococcus aureus, Streptococcus mutans, T2 bacteriophage, H1N1, HCoV-NL63, vesicular stomatitis virus, bovine coronavirus. Silane functionalizing agents and polymers were used to coat the titanium (Ti) metal implants to introduce superhydrophobic features to avoid microbial adhesion. TiO₂ nanocomposite coatings in dental and orthopaedic metal implants disclosed exceptional bio-corrosion resistance, durability, biocompatibility, bone-formation capability, and long-term antimicrobial efficiency. Moreover, the commercial trend, techno-economics, challenges, and prospects of antimicrobial nanocomposite coatings are also discussed briefly.

Non-surgical treatment for periodontitis and peri-implantitis: longitudinal clinical and bacteriological findings-A case report with a 7-year follow-up evaluation

The aim of this report is to show that periodontitis and peri-implantitis with horizontal bone resorption in a 68-year-old male patient were successfully treated by non-surgical treatment. Scaling with an ultrasonic device was performed for moderate periodontitis around the mandibular left first premolar and moderate peri-implantitis around the maxillary right molar implants. Root planing with a metal curette was performed for the periodontal site, and debridement with a plastic curette was performed for the peri-implant site. A month after treatment, probing depth decreased from 5 to 2 mm at the periodontal site and 8 to 3 mm at the peri-implant site. The investigation of bacterial composition by sequencing the 16S rRNA gene amplicons showed that the composition similarly changed at both sites, 5 years after treatment; the change reflected the typical recovery of periodontitis. The clinical condition was maintained for 7 years after treatment at both sites. This was a successful case of non-surgical treatment for peri-implantitis with horizontal bone resorption, promoting recovery of the microbiota from dysbiotic shift.

Efficacy of Adjunctive Antimicrobial Photodynamic Therapy to Mechanical Debridement in the Treatment of Peri-implantitis or Peri-implant Mucositis in Smokers: A Systematic Review and Meta-analysis

This systematic review and meta-analysis aimed to determine whether adjunctive use of antimicrobial photodynamic therapy (a-PDT) in peri-implant diseases improves clinical outcomes in smokers. An electronic search was performed in MEDLINE (through PubMed), Scopus, Cochrane Library, Embase, Web of Science and Google Scholar. The primary outcome measures were bleeding on probing (BOP) and pocket depth (PD). Plaque index (PI) was the secondary outcome. Four RCTs, (188 participants) comprised of 118 cigarette smokers, 38 E-cig smokers and 32 water pipe smokers with follow-up periods ranged from 6 weeks to 6 months were recruited. All trials applied diode laser in one session with wavelengths ranged from 660 to 670 nm. There was a significant difference between mechanical debridement (MD)+a-PDT and MD alone groups in PD (WMD = -1.26 mm, 95% CI: -2.19 to -0.32, P = 0.01) and PI (WMD = -10.60%, 95% CI: -14.46 to -6.74, P < 0.001) at 3-month follow-up. However, a great amount of heterogeneity was observed (PD: χ² = 199.19, I² = 98%, P < 0.001 and PI: χ² = 25.63, I² = 84.4%, P < 0.001). Due to methodological heterogeneity and small number of studies, this systematic review was unable to reach conclusive evidence in regards of adjunctive a-PDT efficacy in improving clinical parameters in smokers.

Erythritol airpolishing in the non-surgical treatment of peri-implantitis: A randomized controlled trial

Objectives

To compare erythritol air polishing with piezoelectric ultrasonic scaling in the non‐surgical treatment of peri‐implantitis.

Material and methods

Eighty patients (n = 139 implants) with peri‐implantitis (probing pocket depth (PPD) ≥5 mm, marginal bone loss (MBL) ≥2 mm as compared to bone level at implant placement, bleeding, and/or suppuration on probing (BoP/SoP)) were randomly allocated to air polishing or ultrasonic treatment. The primary outcome was mean BoP (%) at 3 months after therapy (T3). Secondary outcomes were mean SoP (%), plaque score (Plq) (%), PPD (mm), MBL (mm), full mouth periodontal scores (FMPS) (%), levels of 8 classical periodontal pathogens, and treatment pain/discomfort (Visual Analog Scale, VAS). Patients who were considered successful at T3 were additionally assessed at 6, 9, and 12 months. Differences between both groups were analyzed using multilevel statistics.

Results

Three months after therapy, no significant difference in mean BoP (%) between the air polishing and ultrasonic therapy was found (crude analysis β (95% CI) −0.037 (−0.147; 0.073), p = .380). Neither secondary outcomes SoP (%), Plq (%), PPD (mm), MBL (mm), FMPS (%), and periodontal pathogens showed significant differences. Treatment pain/discomfort was low in both groups (VAS score airpolishing group 2.1 (±1.9), ultrasonic 2.6 (±1.9); p = .222). All successfully treated patients at T3 (18.4%) were still considered successful at 12‐month follow‐up.

Conclusions

Erythritol air polishing seems as effective as piezoelectric ultrasonic scaling in the non‐surgical treatment of peri‐implantitis, in terms of clinical, radiographical, and microbiological parameters. However, neither of the proposed therapies effectively resolved peri‐implantitis. Hence, the majority of patients required further surgical treatment.

Comparison of the effects of air-powder abrasion, chemical decontamination, or their combination in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo study

OBJECTIVES

To compare, using an ex vivo model, the biofilm removal of three surface decontamination methods following surgical exposure of implants failed for severe peri-implantitis.

MATERIALS AND METHODS

The study design was a single-blind, randomized, controlled, ex vivo investigation with intra-subject control. Study participants were 20 consecutive patients with at least 4 hopeless implants, in function for >12 months and with progressive bone loss exceeding 50%, which had to be explanted. Implants of each patient were randomly assigned to the untreated control group or one of the three decontamination procedures: mechanical debridement with air-powder abrasion, chemical decontamination with hydrogen peroxide and chlorhexidine gluconate, or combined mechanical-chemical decontamination. Following surgical exposure, implants selected as control were retrieved, and afterwards, test implants were decontaminated according to allocation and carefully explanted with a removal kit. Microbiological analysis was expressed in colony-forming-units (CFU/ml).

RESULTS

A statistically significant difference (p < 0.001) in the concentrations of CFU/ml was found between implants treated with mechanical debridement (531.58 ± 372.07) or combined mechanical-chemical decontamination (954.05 ± 2219.31) and implants untreated (37,800.00 ± 46,837.05) or treated with chemical decontamination alone (29,650.00 ± 42,596.20). No statistically significant difference (p = 1.000) was found between mechanical debridement used alone or supplemented with chemical decontamination. Microbiological analyses identified 21 microbial species, without significant differences between control and treatment groups.

CONCLUSIONS

Bacterial biofilm removal from infected implant surfaces was significantly superior for mechanical debridement than chemical decontamination.

CLINICAL RELEVANCE

The present is the only ex vivo study based on decontamination methods for removing actual and mature biofilm from infected implant surfaces in patients with peri-implantitis.

A Roadmap towards Precision Periodontics

Periodontitis is among the most common health conditions and represents a major public health issue related to increasing prevalence and seriously negative socioeconomic impacts. Periodontitis-associated low-grade systemic inflammation and its pathological interplay with systemic conditions additionally raises awareness on the necessity for highly performant strategies for the prevention and management of periodontitis. Periodontal diagnosis is the backbone of a successful periodontal strategy, since prevention and treatment plans depend on the accuracy and precision of the respective diagnostics. Periodontal diagnostics is still founded on clinical and radiological parameters that provide limited therapeutic guidance due to the multifactorial complexity of periodontal pathology, which is why biomarkers have been introduced for the first time in the new classification of periodontal and peri-implant conditions as a first step towards precision periodontics. Since the driving forces of precision medicine are represented by biomarkers and machine learning algorithms, with the lack of periodontal markers validated for diagnostic use, the implementation of a precision medicine approach in periodontology remains in the very initial stage. This narrative review elaborates the unmet diagnostic needs in periodontal diagnostics, the concept of precision periodontics, periodontal biomarkers, and a roadmap toward the implementation of a precision medicine approach in periodontal practice.

Network meta-analysis of the treatment efficacy of different lasers for peri-implantitis

The aim of this study was comparing different lasers with conventional non-surgical treatment (CNT) for the management of peri-implantitis, regarding probing depth (PD), plaque index (PLI), clinical attachment level (CAL), and sulcus bleeding index (SBI). Randomized controlled trials (RCTs) on different lasers and CNT for peri-implantitis were searched. Pairwise and network meta-analyses were performed to analyze the PD, PLI, CAL, and SBI outcomes. The risk of bias, evidence quality, statistical heterogeneity, and ranking probability were also evaluated. Eleven studies were included in this study, involving three types of lasers. Diode + CNT had significantly superior efficacy to CNT alone, regarding PD reduction, while Er:YAG + CNT had significantly superior efficacy than CNT in terms of the PLI, CAL, and SBI. The highest probability of being most effective for PD was diode + CNT (49%), while Er:YAG + CNT had the highest probability of improving the PLI, CAL, and SBI (66%, 53%, and 79%, respectively). Diode + CNT was significantly superior for PD management in peri-implantitis compared with CNT alone, while Er:YAG + CNT significantly improved the PLI, CAL, and SBI. Therefore, Er:YAG + CNT might be recommended methods considered for management of peri-implantitis.

Changes in the surface topography and element proportion of clinically failed SLA implants after in vitro debridement by different methods

OBJECTIVE

To evaluate the surface topography and element proportion changes in clinically failed implants after different modalities in vitro debridement and to compare the cleaning effect of different method combinations.

MATERIAL AND METHODS

Thirty clinical failed implants were treated by different debridement methods in vitro as follows: Group 1: physiologic saline irrigation; Group 2: glycine powder air polishing; Group 3: glycine powder air polishing + ethylenediaminetetraacetic acid (EDTA); Group 4: polyetheretherketone (PEEK) tip ultrasonic scaling; and Group 5: PEEK tip ultrasonic scaling + EDTA. The relative contaminated area reduction (RCAR), visual analogue scale (VAS, the higher value means, the better cleaning effect) and surface roughness were assessed using scanning electron microscopy (SEM), stereoscopic microscopy (SM) and white light interferometry (WLI). Surface chemistry was determined by energy dispersive spectroscopy (EDS).

RESULTS

Group 4 and Group 5 showed higher RCARs (82.90%, 82.89%), VAS scores (2.61, 2.33) and roughness reductions (-0.85 μm, -1.80 μm). Group 3 attained the highest decrease of C% (carbon, -26.67%), O% (oxygen, -13.71%) and N% (nitrogen, -5.66%), and the highest increase of Ti% (titanium, 49.67%). PEEK remnants were detected on the implant surface of Groups 4 and 5.

CONCLUSION

Within the limitation of the present in vitro design, PEEK tip ultrasonic scaling was more effective in eliminating visible contamination, while glycine powder air polishing combined with EDTA treatment was more conducive to expose the original surface element distribution. Both methods have their own advantages in decontamination, but none of them could reconstruct the surface as the pristine implant.

Effect of a single initial phase of non-surgical treatment of peri-implantitis: Abrasive air polishing versus ultrasounds. A prospective randomized controlled clinical study

Background

Non-surgical treatment of peri-implantitis includes a correct mechanical debridement of the implant surface to reduce the inflammation and recondition the soft tissues. The aim of the study was to evaluate the results of a single phase of non-surgical therapy by comparing the effect of curettes and ultrasounds versus curettes and abrasive air polisher (Air-Flow) in the peri-implant tissue conditions, and patient satisfaction.

Material and Methods

A double-blind randomized and controlled prospective clinical study was conducted on patients in peri-implant maintenance phase diagnosed of peri-implantitis treated in the Oral Surgery Unit of the Stomatology Department of the Faculty of Medicine and Dentistry of the University of Valencia, between September of 2017 and May of 2018. They were divided into 2 groups: Group 1: curettes and ultrasounds, and Group 2: curettes and Air-Flow. The clinical and radiological baseline parameters were evaluated after 3-weeks of treatment, as well as patient satisfaction.

Results

The sample included 34 patients. Group 1 (17 patients, 38 implants) and Group 2 (17 patients, 32 implants). All the variables improved statistically significantly after treatment in both groups, with the exception of recessions and keratinized mucosa and bone loss that did not vary. When comparing both groups, the type of treatment did not influence the majority of the variables, with the exception of the plaque index (p=0.011) and modified bleeding index from the palatine (p=0.048), which reduced statistically significant in the group 2, as well as the patient satisfaction which was higher in the group 2 (p<0.001).

Conclusions

An initial phase of non-surgical treatment achieves an improvement of the peri-implant clinical parameters, thought the method of debridement used seems not to influence.

Key words:Peri-implantitis, peri-implant disease, non-surgical treatment, air-abrasive device, mechanical debridement.

Non-surgical peri-implantitis treatment using a pocket irrigator device; clinical, microbiological, radiographical and patient-centred outcomes-A pilot study

Aim

The aim of this prospective cohort study was to assess the effect of a pocket irrigator/evacuator device (IED) in the non‐surgical treatment of peri‐implantitis.

Material and Methods

In total 24 patients having 38 implants diagnosed with peri‐implantitis were included in this study. Peri‐implant pockets were irrigated six times in three consecutive weeks. The primary outcome was bleeding on probing (BoP). Secondary outcome parameters included plaque index (Pl), suppuration on probing (SoP), probing pocket depth (PPD), marginal bone loss (MBL), presence and numbers of periodontal pathogens. Parameters were assessed at baseline and 3 months after the last treatment. Treatment pain perception was scored using the visual analog scale (VAS) after the first and last treatment.

Results

At 3 months, IED treatment revealed significant reduction of peri‐implant BoP (71% [±20] vs 57% [±28] [P = .014]) and peri‐implant plaque scores (10 [±14] to 5 [±9] [P = .039] [T0 vs T3 respectively]). Significant reduction in mean peri‐implant PPD from 4.92 mm (SD ± 1.28) to 4.66 mm (SD ± 1.35) (P = .041) was observed. In addition, a reduction in VAS pain score between the first and the last (6th) treatment was found (P = .039). No reduction in SoP (P = .088) was found. No changes in mean periodontal full mouth plaque, BOP, SOP and PPD levels, MBL and microbiological outcomes were found.

Conclusion

Beneficial clinical effects in terms of BoP, PPD and PI were found at 3 months after IED treatment. However, the IED does not seem to effectively treat peri‐implantitis in terms of disease resolution.

Surgical treatment of peri-implantitis defects with two different xenograft granules: A randomized clinical pilot study

Objectives

To investigate whether xenograft EB (EndoBon) is non‐inferior to xenograft BO (Bio‐Oss) when used in reconstructive surgery of peri‐implant osseous defects.

Materials and methods

Dental patients with one implant each demonstrating peri‐implantitis were randomized to receive surgical debridement and defect fill with either BO or EB. Changes in bone level (BL) and intrabony defect depth (IDD) evaluated radiographically were the primary outcomes. The secondary outcomes included changes in probing pocket depth (PPD), bleeding on probing (BoP), and suppuration on probing (SoP). All outcomes were recorded before treatment and at 6 and 12 months post‐treatment.

Results

Twenty‐four patients (n = 11 BO, n = 13 EB) completed the study. Both groups demonstrated significant within‐group improvements in all clinical and radiographic parameters at 6 and 12 months (p ≤ .001). At 12 months, both groups presented with IDD reductions of 2.5–3.0 mm on average. The inter‐group differences were not statistically significant at all time points and for all the examined parameters (p > .05). While the radiographic defect fill in both groups exceeded > 1 mm and can be considered treatment success, successful treatment outcomes as defined by Consensus Reporting (no further bone loss, PPD ≤ 5 mm, no BOP, and no SoP) were identified in 2/11 (18%) BO and 0/13 (0%) EB individuals (Fisher's exact test, p = .199).

Conclusions

Within the limitations of this pilot study, the application of xenograft EB showed to be non‐inferior to xenograft BO when used in reconstructive surgery of peri‐implant osseous defects.

Peri-implantitis Update: Risk Indicators, Diagnosis, and Treatment

Despite the success rates of dental implants, peri-implantitis presents as the most common complication in implant dentistry. This review discusses various factors associated with peri-implantitis and various available treatments, highlighting their advantages and disadvantages. Relevant articles on peri-implantitis published in English were reviewed from August 2010 to April 2020 in MEDLINE/PubMed, Scopus, and ScienceDirect. The identified risk indicators of peri-implant diseases are plaque, smoking, history of periodontitis, surface roughness, residual cement, emergence angle >30 degrees, radiation therapy, keratinized tissue width, and function time of the implant, sex, and diabetes. Peri-implantitis treatments can be divided into nonsurgical (mechanical, antiseptic, and antibiotics), surface decontamination (chemical and laser), and surgical (air powder abrasive, resective, and regenerative). However, mechanical debridement alone may fail to eliminate the causative bacteria, and this treatment should be combined with other treatments (antiseptics and surgical treatment). Surface decontamination using chemical agents may be used as an adjuvant treatment; however, the definitive clinical benefit is yet not proven. Laser treatment may result in a short-term decrease in periodontal pocket depth, while air powder abrasive is effective in cleaning a previously contaminated implant surface. Surgical elimination of a pocket, bone recontouring and plaque control are also effective for treating peri-implantitis. The current evidence indicates that regenerative approaches to treat peri-implant defects are unpredictable.

Bioactive Healing Abutment as a Potential Tool for the Treatment of Peri-Implant Disease—In Vitro Study

The common use of dental implants for dental reconstruction poses new treatment challenges for physicians, peri-implantitis being a particularly difficult one. Micro-organisms, including drug-resistant Staphylococcus spp. strains, play a crucial role in the etiology of peri-implantitis. In this paper, the authors assess the efficacy of a bioactive healing abutment (BHA) of their own design for the local release of antibiotics as a potential tool for the treatment of peri-implant disease. BHA filled with a collagen material, combined with the antibiotics clindamycin and tetracycline, was tested in vitro by disk diffusion assay. Antibacterial activity was observed for the chosen Staphylococcus aureus and Staphylococcus epidermidis bacterial strains. In addition, the impact of titanium discs (which were used to make the BHA) was monitored. The results show that the zone diameter breakpoints for BHA are higher than those of standard absorbent paper discs in both tested strains for both tested antibiotics. This work demonstrates that the proposed BHA can serve as an effective and precise drug carrier. The release of antibiotics from the described implant device is easy to control and allows for an effective local antibacterial in vitro treatment. The procedure is inexpensive, easy to perform, and repeatable.

Nonsurgical Treatment of Peri-Implantitis: Case Series

Peri-implantitis is one of the most important biological complication of dental implants. It has inflammatory nature, proved association with plaque accumulation in peri-implant tissues, and can be progressive on background of several factors, like comorbidity factors and bad habits. The prophylaxis and different methods of treatment were discussed during last 30 years, and surgical and nonsurgical techniques have their foes, benefits, and disadvantages. In this article, we describe the case series of various nonsurgical treatments of peri-implantitis with the use of protocols based on the application of local antibiotics (doxycycline, lincomycin, and erythromycin), mechanical and chemical debridement of dental implant surface, and mini-invasive regenerative technique with injections of bovine collagen. All these three cases demonstrated good results with the maintenance of bone level and absence of clinical signs of inflammation for at least a year according to the X-ray imaging (bone defect volume) and clinic assessments (probing depth, bleeding or suppuration, mucosa color, and pain presence).

Short-term comparison of two non-surgical treatment modalities of peri-implantitis: Clinical and microbiological outcomes in a two-factorial randomized controlled trial

AIM

To compare the efficacy of two different therapies (amino acid glycine abrasive powder and a desiccant material) and their combination in the non-surgical treatment of peri-implantitis.

MATERIALS AND METHODS

This was an examiner-blind randomized clinical trial, with 2-factorial design with a follow-up of 6 months. The combination of the two factors resulted in four interventions: (a) non-surgical debridement alone (C); (b) non-surgical debridement and a desiccant material (H); (c) non-surgical debridement and glycine powder (G); and (d) non-surgical debridement, desiccant material and glycine powder (HG).

RESULTS

Sixty-four patients with peri-implantitis were randomized, 16 for each intervention. After six months, two implants failed in the G intervention. Mean pocket depth reduction was higher in patients treated with the desiccant material (estimated difference: 0.5 mm; 95% CI from 0.1 to 0.9 mm, p = .0229) while there was no difference in the patients treated with glycine powder (estimated difference: 0.1 mm; 95% CI from -0.3 to 0.5 mm, p = .7333). VAS for pain during intervention and VAS for pain after one week were higher for patients treated with glycine powder (p = .0056 and p = .0339, respectively). The success criteria and other variables did not reveal differences between interventions.

CONCLUSIONS

In this 6-month follow-up study, pocket reduction was more pronounced in patients using the desiccant material. Pain was higher in patients using glycine. All the interventions resulted in low success rate.

Bactericidal activity and recovery effect of hydroxyl radicals generated by ultraviolet irradiation and silver ion application on an infected titanium surface

This study investigated the bactericidal effect, the underlying mechanisms of treatment, and recovery of biocompatibility of the infected titanium surface using a combination treatment of silver ion application and ultraviolet-A (UV-A) light irradiation. Streptococcus mutans and Aggregatibacter actinomycetemcomitans were used in suspension and as a biofilm on a titanium surface to test for the bactericidal effect. The bactericidal effect of the combination treatment was significantly higher than that of silver ion application or UV-A light irradiation alone. The bactericidal effect of the combination treatment was attributable to hydroxyl radicals, which generated from the bacterial cell wall and whose yield increased with the silver concentration. To assess the biocompatibility, proliferation and calcification of MC3T3E1 cells were evaluated on the treated titanium surface. The treated titanium screws were implanted into rat tibias and the removal torques were measured 28 days post-surgery. The titanium surface that underwent the combination treatment exhibited recovery of biocompatibility by allowing cellular proliferation or calcification at levels observed in the non-infected titanium surfaces. The removal torque 28 days after surgery was also comparable to the control values. This approach is a novel treatment option for peri-implantitis.

The Microbiome of Peri-Implantitis: A Systematic Review and Meta-Analysis

This review aimed to systematically compare microbial profiles of peri-implantitis to those of periodontitis and healthy implants. Therefore, an electronic search in five databases was conducted. For inclusion, studies assessing the microbiome of peri-implantitis in otherwise healthy patients were considered. Literature was assessed for consistent evidence of exclusive or predominant peri-implantitis microbiota. Of 158 potentially eligible articles, data of 64 studies on 3730 samples from peri-implant sites were included in this study. Different assessment methods were described in the studies, namely bacterial culture, PCR-based assessment, hybridization techniques, pyrosequencing, and transcriptomic analyses. After analysis of 13 selected culture-dependent studies, no microbial species were found to be specific for peri-implantitis. After assessment of 28 studies using PCR-based methods and a meta-analysis on 19 studies, a higher prevalence of Aggregatibacter actinomycetemcomitans and Prevotella intermedia (log-odds ratio 4.04 and 2.28, respectively) was detected in peri-implantitis biofilms compared with healthy implants. Actinomyces spp., Porphyromonas spp. and Rothia spp. were found in all five pyrosequencing studies in healthy-, periodontitis-, and peri-implantitis samples. In conclusion, the body of evidence does not show a consistent specific profile. Future studies should focus on the assessment of sites with different diagnosis for the same patient, and investigate the complex host-biofilm interaction.

Graphene Oxide Enables the Reosteogenesis of Previously Contaminated Titanium In Vitro

The main goal of peri-implantitis treatment is to control infection and arrest bone loss, which requires the removal of polymicrobial biofilms on the implant surface and the reduction of tissue invasion. Additionally, prognosis can be improved if reosseointegration occurs on previously contaminated implants. To evaluate whether graphene oxide (GO) can remove polymicrobial biofilms, biofilms were established on titanium surfaces in vitro and treated with different methods: group B, removed only with brushing; group G, treated with different GO concentrations (64, 128, 256, and 512 μg/mL); group GB, combined treatments of groups B and G; and group C, untreated. Subsequently, to evaluate reosteogenesis on previously contaminated titanium, 4 groups were used: groups C, B, GB-256, and GB-512 (treated with 256 and 512 μg/mL of GO, respectively). Intact clean titanium (IC) was used as a control. Additionally, cell behavior on IC treated with GB-256 (IGB-256) and GB-512 (IGB-512) was compared with that of the GB-256 and GB-512 groups, respectively. The results showed that at high concentrations (≥256 μg/mL), GO eliminated residual bacteria and inhibited biofilm reformation after brushing, whereas neither GO nor brushing alone could achieve this. Bone marrow-derived mesenchymal stem cell viability in groups GB-256 and IC was higher than that in groups GB-512, C, and B (P < 0.05). No significant difference was found between group GB-256 and group IC (P > 0.05). Osteogenic differentiation of bone marrow-derived mesenchymal stem cells in group GB-256 was higher than that in groups IC, GB-512, C, and B. No difference was found between groups IGB-256 and IGB-512 and groups GB-256 and GB-512, respectively (P > 0.05). In conclusion, 256 μg/mL of GO combined with brushing significantly removed polymicrobial biofilms that remained on the previously contaminated titanium surfaces. The bone marrow-derived mesenchymal stem cell osteogenic potential was regained or even enhanced on the titanium surfaces treated this way in vitro, which might provide a new idea for treating peri-implantitis.

Targeting Pathogenic Biofilms: Newly Developed Superhydrophobic Coating Favors a Host-Compatible Microbial Profile on the Titanium Surface

Polymicrobial infections are one of the most common reasons for inflammation of surrounding tissues and failure of implanted biomaterials. Because microorganism adhesion is the first step for biofilm formation, physical-chemical modifications of biomaterials have been proposed to reduce the initial microbial attachment. Thus, the use of superhydrophobic coatings has emerged because of their anti-biofilm properties. However, these coatings on the titanium (Ti) surface have been developed mainly by dual-step surface modification techniques and have not been tested using polymicrobial biofilms. Therefore, we developed a one-step superhydrophobic coating on the Ti surface by using a low-pressure plasma technology to create a biocompatible coating that reduces polymicrobial biofilm adhesion and formation. The superhydrophobic coating on Ti was created by the glow discharge plasma using Ar, O_2, and hexamethyldisiloxane gases, and after full physical, chemical, and biological characterizations, we evaluated its properties regarding oral biofilm inhibition. The newly developed coating presented an increased surface roughness and, consequently, superhydrophobicity (contact angle over 150°) and enhanced corrosion resistance (p < 0.05) of the Ti surface. Furthermore, proteomic analysis showed a unique pattern of protein adsorption on the superhydrophobic coating without drastically changing the biologic processes mediated by proteins. Additionally, superhydrophobic treatment did not present a cytotoxic effect on fibroblasts or reduction of proliferation; however, it significantly reduced (≈8-fold change) polymicrobial adhesion (bacterial and fungal) and biofilm formation in vitro. Interestingly, superhydrophobic coating shifted the microbiological profile of biofilms formed in situ in the oral cavity, reducing by up to ≈7 fold pathogens associated with the peri-implant disease. Thus, this new superhydrophobic coating developed by a one-step glow discharge plasma technique is a promising biocompatible strategy to drastically reduce microbial adhesion and biofilm formation on Ti-based biomedical implants.

Pyrosequencing of the subgingival microbiome in peri-implantitis after non-surgical mechanical debridement therapy

BACKGROUND AND OBJECTIVES

Peri-implantitis remains a challenge for dental implant therapy, and the prognosis of non-surgical therapy for peri-implantitis is unsatisfactory. In order to reveal the impact of non-surgical mechanical debridement therapy on microbial communities, we investigated the subgingival microbial communities of healthy implants and implants with peri-implantitis, both before and after the therapy.

MATERIAL AND METHODS

Subgingival plaques were collected from patients with healthy dental implants (HC; n = 10) and from patients with peri-implantitis (n = 13) before and after non-surgical mechanical debridement therapy. The treatment was conducted using curettes for submucosal debridement followed by irrigation with 0.2% (w/v) chlorhexidine, with re-examination 1 month later. 16S rRNA pyrosequencing was used to analyze the subgingival microbiome, and co-occurrence networks were adopted to explore the interactions between pathogens in the microbial communities.

RESULTS

A total of 506 955 high-quality reads were generated, and 2222 operational taxonomic units were finally detected using a 97% similarity cutoff, with a mean of 249 ± 69 per sample. The peri-implantitis sites harbored similar microbial communities before and after the treatment, as demonstrated by the microbial diversity, relative abundance, and prevalence of bacteria. Most importantly, the microbial community structures were stable before and after non-surgical therapy based on the microbial diversity and bacterial composition, as well as the interactions between key pathogens, including Enterobacteriaceae, Selenomonas sputigena, Parvimonas, Eubacterium infirmum, Campylobacter gracilis, Tannerella forsythia, and Fusobacterium, which were measured using a co-occurrence network analysis. Periodontal pathogens were also detected in subgingival plaque after the treatment. Distinct microbial communities were found between the healthy and peri-implantitis sites.

CONCLUSION

Our results demonstrate that non-surgical mechanical debridement therapy did not significantly affect the subgingival microbial communities in peri-implantitis, and the stable microbial networks created via interactions among pathogens may be responsible for the poor prognosis of peri-implantitis treatment.

UV Light Assisted Coating Method of Polyphenol Caffeic Acid and Mediated Immobilization of Metallic Silver Particles for Antibacterial Implant Surface Modification

Titanium implants are extensively used in biomedical applications due to their excellent biocompatibility, corrosion resistance, and superb mechanical stability. In this work, we present the use of polycaffeic acid (PCA) to immobilize metallic silver on the surface of titanium materials to prevent implant bacterial infection. Caffeic acid is a plant-derived phenolic compound, rich in catechol moieties and it can form functional coatings using alkaline buffers and with UV irradiation. This combination can trigger oxidative polymerization and deposition on the surface of metallic substrates. Using PCA can also give advantages in bone implants in decreasing inflammation by decelerating macrophage and osteoclast activity. Here, chemical and physical properties were investigated using FE-SEM, EDS, XPS, AFM, and contact angle. The in vitro biocompatibility and antibacterial studies show that PCA with metallic silver can inhibit bacterial growth, and proliferation of MC-3T3 cells was observed. Therefore, our results suggest that the introduced approach can be considered as a potential method for functional implant coating application in the orthopedic field.

Is Peri-Implantitis Curable?

Peri-implant mucositis and peri-implantitis are clinically associated with inflammation of soft tissue around implants; however, peri-implantitis is associated with radiographic bone loss. Recently a new classification scheme-peri-implant health, peri-implant mucositis, peri-implantitis, and peri-implant soft-tissue and hard-tissue deficiencies-was introduced. Although various clinical interventions to treat peri-implant diseases have been suggested, early diagnosis and treatment is the key to successful outcomes. Clinicians can select nonsurgical or surgical techniques according to the clinical parameters present, although surgical intervention seems to be more effective in treating peri-implantitis. The best approach to treat peri-implantitis remains controversial.

Hydrophobicity of graphene as a driving force for inhibiting biofilm formation of pathogenic bacteria and fungi

OBJECTIVE

To evaluate the surface and wettability characteristics and the microbial biofilm interaction of graphene coating on titanium.

METHODS

Graphene was deposited on titanium (Control) via a liquid-free technique. The transfer was performed once (TiGS), repeated two (TiGD) and five times (TiGV) and characterized by AFM (n=10), Raman spectroscopy (n=10), contact angle and SFE (n=5). Biofilm formation (n=3) to Streptococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans was evaluated after 24h by CV assay, CFU, XTT and confocal microscopy. Statistics were performed by one-way Anova, Tukey's tests and Pearson's correlation analysis at a pre-set significance level of 5 %.

RESULTS

Raman mappings revealed coverage yield of 82 % for TiGS and ≥99 % for TiGD and TiGV. Both TiGD and TiGV presented FWHM>44cm^-1 and I_D/I_G ratio<0.12, indicating multiple graphene layers and occlusion of defects. The contact angle was significantly higher for TiGD and TiGV (110° and 117°) comparing to the Control (70°). The SFE was lower for TiGD (13.8mN/m) and TiGV (12.1mN/m) comparing to Control (38.3mN/m). TiGD was selected for biofilm assays and exhibited significant reduction in biofilm formation for all microorganisms compared to Control. There were statistical correlations between the high contact angle and low SFE of TiGD and decreased biofilm formation.

SIGNIFICANCE

TiGD presented high quality and coverage and decreased biofilm formation for all species. The increased hydrophobicity of graphene films was correlated with the decreased biofilm formation for various species.

Avaliação do efeito de cepas probióticas em biofilme de S. aureus sobre discos de titânio com superfície tratada

Resumo Introdução As doenças peri-implantares apresentam como um dos principais fatores etiológicos o biofilme bacteriano, geralmente formado por uma microbiota semelhante à das doenças periodontais. Seu tratamento está centrado na descontaminação da superfície do implante e na remoção mecânica do biofilme, podendo ainda estar associado à administração de agentes antimicrobianos. Nesse sentido, tem sido cogitada a utilização de probióticos, que são microrganismos benéficos à saúde e que podem ter grande importância na cavidade oral, como coadjuvante no tratamento das peri-implantites. Objetivo Avaliar o efeito das cepas probióticas de Lactobacillus brevis e Bifidobacterium bifidum no crescimento do biofilme monoespécie de Staphylococcus aureus. Material e método Discos de titânio padronizados e com superfície tratada foram submersos em meio contendo caldo BHI e Staphylococcus aureus durante sete dias. Após esse período, o caldo foi retirado, os discos foram lavados e, então, introduzidos em um novo caldo BHI contendo as suspensões probióticas, sendo assim comparados a um grupo controle, sem probióticos. As amostras foram incubadas por 24h e então foram realizadas as diluições e a contagem das UFC (unidades formadoras de colônia) para Staphylococcus aureus. Resultado Após análise estatística dos dados, observou-se que a adição de ambos os probióticos resultaram em redução significativa (p<0,05) de UFC, quando comparados ao controle. Conclusão Conclui-se que os probióticos analisados (Lactobacillus brevis e Bifidobacterium bifidum) reduziram consideravelmente o crescimento do patógeno Staphylococcus aureus. Além disso, a cepa de Lactobacillus brevis apresentou efeito inibidor superior ao da cepa Bifidobacterium bifidum para ser utilizada como controle do biofilme bacteriano de Staphylococcus aureus.

Investigation of the antibacterial effect of laser irradiation and chemical agent on human oral biofilms contaminated titanium discs

INTRODUCTION

A main challenge in treatment of peri-implant disease is the effective decontamination of the implant surface. This challenge has always been a problem, associated with the treatment of these diseases with regard to the difficulty in removing and eliminating bacterial biofilm from the surface of dental implants, especially rough surfaces. The aim of this in-vivo study was to evaluate the effect of five different antimicrobial methods in reducing bacteria adhering to titanium surfaces.

MATERIALS AND METHODS

In the present in-vivo study, the contaminated discs, except for the negative control group, randomly underwent one of five treatments: Erbium: Yattrium Aluminum Garnet (Er-YAG) laser, plastic curette, 0.12% chlorhexidine, aPDT, and 810 nm diode laser. A pectrophotometer was used to measure Optical Density (OD) in case of aerobic microorganisms. Colony-Forming Units (CFUs) were used for anaerobic bacteria. Then, all the analyses were carried out at a significance level of α = 0.05 through SPSS software.

FINDINGS

One-way analysis of variance (ANOVA) of aerobic bacteria showed a significant difference among 6 groups in terms of OD variations during a 0-24 h time interval (P < 0.001). The results of Kruskal-Wallis test were used to investigate the effect of study methods on anaerobic bacteria after 48 h, and the results showed a significant difference among 6 groups in terms of CFUs (P < 0.001).

CONCLUSION

The results of the present study showed that all five mechanicals (plastic curette), chemical (CHX), laser (810 nm diode and Er: YAG), and aPDT methods could reduce oral biofilms from roughed surfaces of titanium discs. Er: YAG laser and plastic curette had the highest and the lowest effects respectively.

Simplified nonsurgical treatment of peri-implantitis using chlorhexidine and minocycline hydrochloride

Purpose

The present study investigated the outcomes of a newly-developed, simple, and practical nonsurgical treatment modality suitable for most forms of intrabony defects around failing dental implants using intrasulcular delivery of chlorhexidine solution and minocycline hydrochloride (HCl).

Methods

Forty-five dental implants in 20 patients diagnosed with peri-implantitis were included. At baseline and the study endpoint, the probing pocket depth (PPD), clinical attachment level (CAL), and the presence of bleeding on probing (BOP) at 6 sites around each implant were recorded. The radiographic osseous defect morphology at the mesial or distal proximal aspect of each implant was classified as 1) narrow or wide and 2) shallow or deep. For a comparative analysis of bone changes according to the defect morphology, the distance from the implant shoulder to the most coronal bone-to-implant contact point (DIB) at the mesial and distal aspects of each implant was measured at baseline and the endpoint. Patients were scheduled to visit the clinic every 2–4 weeks for intrasulcular irrigation of chlorhexidine and delivery of minocycline HCl.

Results

We observed statistically significant decreases in PPD, CAL, and BOP after treatment. At the endpoint, bone levels increased in all defects, regardless of the osseous morphology of the intrabony defect. The mean DIB change in deep defects was significantly greater than that in shallow defects. Although the mean bone gain in narrow defects was greater than in wide defects, the difference was not statistically significant.

Conclusions

We propose that significant and sustainable improvements in both clinical and radiographic parameters can be expected when intrabony defects around dental implants are managed through a simple nonsurgical approach involving combined intrasulcular chlorhexidine irrigation and local delivery of minocycline HCl.

Debridement of Bacterial Biofilms with TiO2/H2O2 Solutions and Visible Light Irradiation

Objectives

The aim of the study was to explore the debridement efficacy of different solutions of H₂O₂ and rutile particles against Staphylococcus epidermidis and Pseudomonas aeruginosa biofilms attached to titanium surfaces when exposed to visible light.

Materials and Methods

Titanium discs cultivated with biofilms of Staphylococcus epidermidis or Pseudomonas aeruginosa were subjected for 1 min to suspensions consisting of rutile particles mixed with high (950 mM) or low (2 mM) concentrations of H₂O₂ under visible light irradiation (405 nm; 2.1 mW/cm²). Discs were rinsed and the degree of debridement was determined through scanning electron microscopy and viability assessment of the remaining bacteria using luminescence measurements and/or a metabolic activity assay.

Results

Cleaning mixtures containing the higher concentration of H₂O₂ showed a significantly improved debridement compared to the negative control in all experiments. The addition of rutile particles was shown to have a statistically significant effect in one test with S. epidermidis. Limited evidence of the catalytic effect of visible light irradiation was seen, but effects were relatively small and statistically insignificant.

Conclusions

H₂O₂ at a concentration of 950 mM proved to be the strongest contribution to the debridement and bactericidal effect of the cleaning techniques tested in this study.

Surface property alterations and osteoblast attachment to contaminated titanium surfaces after different surface treatments: An in vitro study

BACKGROUND

Studies have reported a high prevalence of peri-implantitis. The etiology of peri-implantitis remains unclear and no available treatments result in total resolution of established peri-implantitis.

PURPOSE

To investigate the factors that interfere with osteoblast adhesion to contaminated titanium surfaces after different surface treatments.

MATERIALS AND METHODS

Grade 4 titanium discs were randomly divided into 5 groups and each group was divided into 2 subgroups, with one contaminated with Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), and the other contaminated with Porphyromonas gingivalis (P. gingivalis). Group 1 did not receive bacterial inoculation or surface debridement and served as a control. Group 2 received A. actinomycetemcomitans or P. gingivalis inoculation, separately. Group 3 received bacterial inoculation and titanium curette debridement, followed by normal saline irrigation. Group 4 received bacterial inoculation, curette debridement, normal saline irrigation, and ultrasonication. Group 5 received bacterial inoculation, curette debridement, normal saline irrigation, and placement in 0.12% chlorhexidine. After various surface treatments, the surface roughness and hydrophilicity of the titanium surface were measured, the number of adhered osteoblast cells was calculated, and the amount of residual lipopolysaccharide (LPS) was quantified.

RESULTS

A. actinomycetemcomitans and P. gingivalis biofilms noticeably reduced surface hydrophilicity. Groups 3-5 showed decreased hydrophilicity and fewer adhered osteoblast cells compared with the control group. Although ultrasonication was more effective in removing LPS than curette debridement and chlorhexidine, cell adhesion was not as high as with clean titanium discs.

CONCLUSIONS

The non-surgical treatment used in this study was not effective in removing LPS from titanium surfaces and increasing osteoblast adhesion. A more effective method to remove LPS completely is required to enhance the treatment outcome of peri-implantitis.