The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces

Electric Current Application on Dental Implant Biofilms: Review

The prevalence of complications due to the presence of biofilms in dental implant surfaces and their relationship with peri-implant diseases, namely peri-implantitis, remain difficult problems to overcome. The information available about the application of electric current on dental implant biofilms; its parameters, namely current level, voltage and exposure time; and related effects are still not enough to understand which individual mechanisms are caused by this technique, culminating in the decrease or eradication of the biofilm. The purpose of this narrative review, based on a systematic search, is to understand the effect of electric current directly applied to biofilms present in dental implants and which parameters are used. For the systematic search, electronic databases including MEDLINE/PubMed, Scopus, and Web of Science, up to and including November 2023, were searched. Seven studies were included. A 12-item checklist was used to assess their methodological quality. All studies used direct/constant electric current; however, that use was not achieved by the same protocol/set-up. Parameters such as current, voltage, resistance, and actuation time were different in all studies. Monospecies and multi-species biofilm were used in the substrate made of titanium. The results indicate that the use of constant and alternating electric current directly applied to dental implant's surfaces is a promising way to treat problems related to biofilms and peri-implant diseases. Future trials, namely in vivo tests, are necessary to reveal all the potential of this treatment.

Zirconia Dental Implants Surface Electric Stimulation Impact on Staphylococcus aureus

Tooth loss during the lifetime of an individual is common. A strategy to treat partial or complete edentulous patients is the placement of dental implants. However, dental implants are subject to bacterial colonization and biofilm formation, which cause an infection named peri-implantitis. The existing long-term treatments for peri-implantitis are generally inefficient. Thus, an electrical circuit was produced with zirconia (Zr) samples using a hot-pressing technique to impregnate silver (Ag) through channels and holes to create a path by LASER texturing. The obtained specimens were characterized according to vitro cytotoxicity, to ensure ZrAg non-toxicity. Furthermore, samples were inoculated with Staphylococcus aureus using 6.5 mA of alternating current (AC). The current was delivered using a potentiostat and the influence on the bacterial concentration was assessed. Using AC, the specimens displayed no bacterial adhesion (Log 7 reduction). The in vitro results presented in this study suggest that this kind of treatment can be an alternative and promising strategy to treat and overcome bacterial adhesion around dental implants that can evolve to biofilm.

In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices

BACKGROUND

We investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface.

METHODS

Discs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs.

RESULTS

Treatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy.

CONCLUSION

AP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device.

The biofilm removal effect and osteogenic potential on the titanium surface by electrolytic cleaning: An in vitro comparison of electrolytic parameters and five techniques

OBJECTIVES

To determine the optimal current and time of electrolytic cleaning (EC), compare its biofilm removal effect with generic treatments and evaluate the influence of EC to surface characteristics and osteogenic potential of SLA titanium (Ti) discs.

MATERIALS AND METHODS

The six-species biofilm-covered Ti discs were placed as cathodes in physiologic saline and subjected to various current and time treatments. The residual biofilms were evaluated to determine the optimal parameters. The contaminated Ti discs were randomized and treated by rotating Ti brush; ultrasonic-scaling with metal tips; ultrasonic-scaling with PEEK tips; air-polishing and EC. The residual biofilms were compared using a lipopolysaccharide kit (LPS), scanning electron microscope (SEM), confocal laser scanning microscopy and colony-forming unit counting. Non-contaminated Ti discs were treated and characterized. The bone marrow mesenchymal stem cells (BMSCs) were cultured on treated non-contaminated Ti discs. The adhesion, proliferation, alkaline phosphatase (ALP) activity and osteocalcin level of BMSCs were assessed.

RESULTS

The parameters at 0.6A5min were considered optimal. For LPS and SEM, EC promoted a significantly greater biofilm removal than the other groups. There were no changes in the Ti discs' colour, topography, roughness and chemical elements after EC, and the electrolysis-treated Ti discs obtained a super-hydrophilic surface. EC positively impacted the proliferation and ALP activity of BMSCs, surpassing the efficacy of alternative treatments.

CONCLUSIONS

EC achieves a near-complete eradication of contaminants on the SLA surface, causes no surface damage with improved hydrophilicity, and promotes the early osteogenic response of BMSCs, which makes it a promising treatment for peri-implantitis.

Evaluation of Different Procedures for Titanium Dental Implant Surface Decontamination-In Vitro Study

Polymicrobial biofilm removal and decontamination of the implant surface is the most important goal in the treatment of periimplantitis. The aim of this study is to evaluate the efficacy of four different decontamination methods for removing Acinetobacter baumannii and Staphylococcus aureus biofilms in vitro. Seventy-five dental implants were contaminated with a bacterial suspension and randomly divided into five groups (n = 15): the negative control group, which received no treatment; the positive control group, treated with 0.2% chlorhexidine; group 1, treated with a chitosan brush (Labrida BioCleanTM, Labrida AS, Oslo, Norway); group 2, treated with a chitosan brush and 0.2% chlorhexidine; and group 3, treated with a device based on the electrolytic cleaning method (GalvoSurge, GalvoSurge Dental AG, Widnau, Switzerland). The colony-forming unit (CFU) count was used to assess the number of viable bacteria in each sample, and statistical analyses were performed. When compared to the negative control group, all the decontamination methods reduced the CFU count. The electrolytic cleaning method decontaminated the implant surface more effectively than the other three procedures, while the chitosan brush was the least effective. Further research in more realistic settings is required to assess the efficacy of the decontamination procedures described in this study.

Dental Implant Surface Decontamination and Surface Change of an Electrolytic Method versus Mechanical Approaches: A Pilot In Vitro Study

Dental implants are the preferred fixed oral rehabilitation for replacing lost teeth. When peri-implant tissues become inflamed, the removal of plaque accumulating around the implant becomes imperative. Recently, several new strategies have been developed for this purpose, with electrolytic decontamination showing increased potential compared to traditional mechanical strategies. In this in vitro pilot study, we compare the efficacy of an electrolytic decontaminant (Galvosurge^®) with an erythritol jet system (PerioFlow^®) and two titanium brushes (R-Brush™ and i-Brush™) in removing Pseudomonas aeruginosa PAO1 biofilms from implants. Changes in the implant surface after each approach were also evaluated. Twenty titanium SLA implants were inoculated with P. aeruginosa and then randomly assigned to each treatment group. After treatment, decontamination efficacy was assessed by quantifying colony-forming units (log10 CFU/cm²) from each implant surface. Scanning electron microscopy was used to analyse changes in the implant surface. With the exception of R-Brush, all treatment strategies were similarly effective in removing P. aeruginosa from implants. Major surface changes were observed only in implants treated with titanium brushes. In conclusion, this pilot study suggests that electrolytic decontamination, erythritol-chlorhexidine particle jet system and i-Brush™ brushing have similar performance in removing P. aeruginosa biofilm from dental implants. Further studies are needed to evaluate the removal of more complex biofilms. Titanium brushes caused significant changes to the implant surface, the effects of which need to be evaluated.

Hard and soft tissue regeneration of severe peri-implantitis defects with the laser-assisted peri-implant defect regeneration technique: 3-year results

PURPOSE

This retrospective cohort study evaluates the regeneration of severe peri-implantitis deficiencies treated with the laser-assisted peri-implant defect regeneration (LAPIDER) approach within a 3-year follow-up.

METHODS

Twenty-four implants with severe peri-implantitis in 18 patients were treated according to the LAPIDER technique. In contrast to classic techniques for reconstructive peri-implantitis surgery with a marginal incision, a buccal split-flap preparation avoiding papillae separation was used. After a coronal flap elevation and a laser-assisted peri-implant defect cleaning, connective tissue and autogenous bone grafting was performed. Primary outcomes were the changes of the marginal bone levels (MBL) and the buccal bone thickness. Secondary outcomes included implant survival, peri-implant probing depths (PPD), bleeding on probing (BOP), recession, width of keratinized mucosa (KMW), thickness of keratinized mucosa (KMT), soft tissue esthetics (PES), and implant success.

RESULTS

MBL improved interproximal by 3.10 ± 2.02 mm (p < 0.001), buccal by 3.49 ± 2.89 mm (p < 0.001), and lingual by 1.46 ± 1.98 mm (p = 0.003); buccal bone thickness by 0.55 ± 0.60 mm (p = 0.005), and 1.01 ± 1.25 mm (p = 0.001) at 1 and 3 mm below reference level. Two implants were removed; 22 implants were still in function at a mean follow-up of 36 months. PPD changed from 5.05 ± 1.39 to 3.08 ± 0.71 mm (p < 0.001); recession was reduced from 2.07 ± 1.70 to 0.91 ± 1.13 mm (p = 0.001); KMW increased from 2.91 ± 1.81 to 4.18 ± 1.67 mm (p = 0.006); KMT improved from 1.73 ± 0.50 to 2.44 ± 0.43 mm (p < 0.001); PES changed from 7.7 ± 2.8 to 10.7 ± 1.9 (p < 0.001). 45.8% to 54.2% of the implants met the criteria of implant success.

CONCLUSIONS

The favorable results document the proof of principle for the regeneration of severe peri-implant hard and soft tissue deficiencies by the LAPIDER treatment approach.

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.

Comparison of decontamination efficacy of two electrolyte cleaning methods to diode laser, plasma, and air-abrasive devices

OBJECTIVE

To compare the in vitro decontamination efficacy of two electrolytic cleaning methods to diode laser, plasma, and air-abrasive devices.

MATERIAL AND METHODS

Sixty sandblasted large-grit acid-etched (SLA) implants were incubated with 2 ml of human saliva and Tryptic Soy Broth solution under continuous shaking for 14 days. Implants were then randomly assigned to one untreated control group (n = 10) and 5 different decontamination modalities: air-abrasive powder (n = 10), diode laser (n = 10), plasma cleaning (n = 10), and two electrolytic test protocols using either potassium iodide (KI) (n = 10) or sodium formate (CHNaO₂) (n = 10) solution. Implants were stained for dead and alive bacteria in two standardized measurement areas, observed at fluorescent microscope, and analyzed for color intensity.

RESULTS

All disinfecting treatment modalities significantly reduced the stained area compared to the untreated control group for both measurement areas (p < 0.001). Among test interventions, electrolytic KI and CHNaO₂ treatments were equally effective, and each one significantly reduced the stained area compared to any other treatment modality (p < 0.001). Efficacy of electrolytic protocols was not affected by the angulation of examined surfaces [surface angulation 0° vs. 60° (staining %): electrolytic cleaning-KI 0.03 ± 0.04 vs. 0.09 ± 0.10; electrolytic cleaning-CHNaO2 0.01 ± 0.01 vs. 0.06 ± 0.08; (p > 0.05)], while air abrasion [surface angulation 0° vs. 60° (staining %): 2.66 ± 0.83 vs. 42.12 ± 3.46 (p < 0.001)] and plasma cleaning [surface angulation 0° vs. 60° (staining %): 33.25 ± 3.01 vs. 39.16 ± 3.15 (p < 0.001)] were.

CONCLUSIONS

Within the limitations of the present in vitro study, electrolytic decontamination with KI and CHNaO₂ was significantly more effective in reducing bacterial stained surface of rough titanium implants than air-abrasive powder, diode laser, and plasma cleaning, regardless of the accessibility of the contaminated implant location.

CLINICAL RELEVANCE

Complete bacterial elimination (residual bacteria < 1%) was achieved only for the electrolytic cleaning approaches, irrespectively of the favorable or unfavorable access to implant surface.

Evidence of re-osseointegration after electrolytic cleaning and regenerative therapy of peri-implantitis in humans: a case report with four implants

Objective

To evaluate re-osseointegration after electrolytic cleaning and regenerative therapy of dental implants with peri-implantitis in humans.

Material and methods

Four dental implants that developed peri-implantitis underwent electrolytic cleaning followed by regenerative therapy with guided bone regeneration. All four implants developed recurrent peri-implantitis and were therefore explanted 6 to 13 months later. Radiographic bone level, probing depth, and bleeding on probing were determined at the time of surgery, 6 months later, and before implant retrieval. The peri-implant tissues were histologically and histomorphometrically analyzed.

Results

All four implants demonstrated radiographic and histological bone gain, reduced probing depth, and bleeding on probing. Radiographic bone gain was 5.8 mm mesially and 4.8 mm distally for implant #1, 3.3 mm and 2.3 mm for implant #2, 3.1 mm and 0.5 mm for implant #3, and 3.5 mm and 2.8 mm for implant #4. The histometric mean and maximum vertical bone gain for implant #1 to #4 was 1.65 mm and 2.54 mm, 3.04 mm and 3.47 mm, 0.43 mm and 1.27 mm, and 4.16 mm and 5.22 mm, respectively. The percentage of re-osseointegration for implant #1 to #4 was 21.0%, 36.9%, 5.7%, and 39.0%, respectively. In one implant, the newly formed bone was deposited directly onto calculus on the implant surface.

Conclusions

We found that (1) re-osseointegration is possible on a formerly contaminated implant surface and (2) the electrolytic cleaning process seems to be effective enough at sites with calculus residues.

Clinical relevance

Since re-osseointegration can be achieved by electrolytic cleaning, this decontamination technique may be considered as a future treatment concept.

Correction: Ratka et al. The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces. J. Clin. Med. 2019, 8, 1397

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Bio-assisted synthesis of bimetallic nanoparticles featuring antibacterial and photothermal properties for the removal of biofilms

Biofilms are responsible for about considerable amounts of cases of bacterial infections in humans. They are considered a major threat to transplant and chronic wounds patients due to their highly resistant nature against antibacterial materials and due to the limited types of techniques that can be applied to remove them. Here we demonstrate a successful in-situ bio-assisted synthesis of dual functionality nanoparticles composed of Silver and Gold. This is done using a jellyfish-based scaffold, an antibacterial material as the templating host in the synthesis. We further explore the scaffold’s antibacterial and photothermal properties against various gram-negative and positive model bacteria with and without photo-induced heating at the Near-IR regime. We show that when the scaffold is loaded with these bimetallic nanoparticles, it exhibits dual functionality: Its photothermal capabilities help to disrupt and remove bacterial colonies and mature biofilms, and its antibacterial properties prevent the regrowth of new biofilms.

Treatment of Periimplantitis with Electrolytic Cleaning versus Mechanical and Electrolytic Cleaning: 18-Month Results from a Randomized Controlled Clinical Trial

Aim of the study: This RCT assesses patients’ 18-month clinical outcomes after the regenerative therapy of periimplantitis lesions using either an electrolytic method (EC) to remove biofilms or a combination of powder spray and an electrolytic method (PEC). Materials and Methods: Twenty-four patients (24 implants) suffering from periimplantitis were randomly treated by EC or PEC followed by augmentation and submerged healing. Probing pocket depth (PPD), Bleeding on Probing (BoP), suppuration, and standardized radiographs were assessed before surgery (T0), 6 months after augmentation (T1), and 6 (T2) and 12 (T3) months after the replacement of the restoration. Results: The mean PPD changed from 5.8 ± 1.6 mm (T0) to 3.1 ± 1.4 mm (T3). While BoP and suppuration at T0 were 100%, BoP decreased at T2 to 36.8% and at T3 to 35.3%. Suppuration was found to be at a level of 10.6% at T2 and 11.8% at T3. The radiologic bone level measured from the implant shoulder to the first visible bone to the implant contact was 4.9 ± 1.9 mm at mesial sites and 4.4 ± 2.2 mm at distal sites at T0 and 1.7 ± 1.7 mm and 1.5 ± 17 mm at T3. Conclusions: Significant radiographic bone fill and the improvement of clinical parameters were demonstrated 18 months after therapy.

Investigation of different electrochemical cleaning methods on contaminated healing abutments in vitro: an approach for metal surface decontamination

BACKGROUND

To evaluate the effects of electrolysis on cleaning the contaminated healing abutment surface and to detect the optimal condition for cleaning the contaminated healing abutment.

METHODS

Ninety healing abutments removed from patients were placed in 1% sodium dodecyl sulfate solution and randomly divided for electrolysis with 7.5% sodium bicarbonate in the following three different apparatuses (N = 30): two stainless steel electrodes (group I), a copper electrode and a carbon electrode (group II), and two carbon electrodes (group III). The samples were placed on cathode or anode with different electric current (0.5, 1, and 1.5 A) under constant 10 V for 5 min. Electrolyte pH before and after electrolysis were measured. Then, the samples were stained with phloxine B and photographed. The proportion of stained areas was calculated. The surface was examined with a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS).

RESULTS

Electrolyte pH decreased after electrolysis at 1 A and 1.5 A in group I and II. Applying cathode at 1 A in group III, the amount of residual contamination was the lowest in all the conditions examined in the present study. SEM images revealed that applying cathode at 1.5 A in group I induced a rough surface from the smooth surface before the treatment. EDS analysis confirmed that the surfaces treated on cathode at 1 A in group III revealed no signs of organic contamination.

CONCLUSION

Electrolysis of using carbon as electrodes, placing the contaminated healing abutments on cathode, and applying the electric current of 1 A at constant 10 V in 7.5% sodium bicarbonate could completely remove organic contaminants from the surfaces. This optimized electrochemical cleaning method seems to be well worth investigation for the clinical management of peri-implant infections.

Is Complete Re-Osseointegration of an Infected Dental Implant Possible? Histologic Results of a Dog Study: A Short Communication

Complete reosseointegration after treatment of periimplantitis was never published yet. This short scientific communication reports about results of a randomized controlled preclinical study. An electrolytic approach was compared to a classical modality (ablative, cotton pellets soaked with sodium chloride solution and H₂O₂. For electrolytic cleaning a complete reosseointegration was achieved in several cases serving as a proof of concept.

Treatment of Peri-implantitis-Electrolytic Cleaning Versus Mechanical and Electrolytic Cleaning-A Randomized Controlled Clinical Trial-Six-Month Results

OBJECTIVES

The present randomized clinical trial assesses the six-month outcomes following surgical regenerative therapy of periimplantitis lesions using either an electrolytic method (EC) to remove biofilms or a combination of powder spray and electrolytic method (PEC).

MATERIALS AND METHODS

24 patients with 24 implants suffering from peri-implantitis with any type of bone defect were randomly treated by EC or PEC. Bone defects were augmented with a mixture of natural bone mineral and autogenous bone and left for submerged healing. The distance from implant shoulder to bone was assessed at six defined points at baseline (T0) and after six months at uncovering surgery (T1) by periodontal probe and standardized x-rays.

RESULTS

One implant had to be removed at T1 because of reinfection and other obstacles. None of the other implants showed signs of inflammation. Bone gain was 2.71 ± 1.70 mm for EC and 2.81 ± 2.15 mm for PEC. No statistically significant difference between EC and PEC was detected. Significant clinical bone fill was observed for all 24 implants. Complete regeneration of bone was achieved in 12 implants. Defect morphology impacted the amount of regeneration.

CONCLUSION

EC needs no further mechanical cleaning by powder spray. Complete re-osseointegration in peri-implantitis cases is possible.