Antimicrobial effects of a pulsed electromagnetic field: an in vitro polymicrobial periodontal subgingival biofilm model

A novel nonsurgical therapy for peri-implantitis using focused pulsed electromagnetic field: A pilot randomized double-blind controlled clinical trial

Pulsed electromagnetic field (PEMF) therapy modulates the immune response and is successfully used in orthopedics to treat osteoarthritis and improve bone regeneration. This may suggest that this treatment may consequently reduce peri-implant soft tissue inflammation and marginal bone loss. To compare clinical, radiographic, and immunological results following nonsurgical treatment for peri-implantitis with or without PEMF therapy. Patients with peri-implantitis were included: pocket probing depth (PPD) between 6 and 8 mm with bleeding on probing (BOP); crestal bone loss between 3 and 5 mm. A novel healing abutment that contained active (test) or inactive (control) PEMF was connected. PEMF was administered via the abutment at exposure ratio of 1/500-1/5000, intensity: 0.05-0.5 mT, frequency: 10-50 kHz for 30 days. Nonsurgical mechanical implant surface debridement was performed. Patients were examined at baseline, 1 and 3 months. Clinical assessment included: plaque index, BOP, PPD, recession, and bone crest level which was radiography measured. Samples of peri-implant crevicular fluid were taken to analyze interleukin-1β (IL-1β). Twenty-three patients (34 implants; 19 control, 15 test) were included. At the follow-up, mean crestal bone loss was lower in the test group at 1 and 3 months (2.48 mm vs. 3.73 mm, p < 0.05 and 2.39 vs. 3.37, p < 0.01). IL-1β levels were also lower in the test group at 2 weeks (72.86 pg/mL vs. 111.7, p < 0.05). Within all the limitation of this preliminary study, the test group improved clinical parameters after a short-term period compared to the control group.

The influence of radio frequency-based toothbrush on the accumulation of calculus and periodontal health: A randomized double-blind controlled prospective study

OBJECTIVES

The use of a toothbrush with radio frequency (RF) has shown to be of benefit regarding the reduction of plaque, calculus, and dental staining and improving teeth shade compared to conventional powered and manual toothbrushes.

AIM

To evaluate the efficacy of the RF toothbrush in the reduction of calculus accumulation and its effect on periodontal parameters as well as subject satisfaction as compared to an identical sham-tooth brush.

MATERIALS AND METHODS

Patients who are under a strict maintenance program were included. Patients were allocated to test (RF toothbrush) or control (sham) randomly and were examined at baseline, one and three months. Clinical photos were taken and a consequential calculus assessment via ImageJ software. Clinical assessment included the following: plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), and recession (REC). Patient satisfaction was assessed via a questionnaire.

RESULTS

Fifty-eight patients (29 control, 29 test) were included. At baseline mean PPD, BOP, PI, REC, and calculus accumulation were similar between the groups. Mean buccal calculus was lower in the test group at one month 4.0% versus 6.7%, p < .05. Calculus accumulation within the groups was lower in the test group at 1 and 3 months when compared to baseline at the buccal aspect (2.8% vs. 8.9%, p < .05% and 3.8% vs. 8.9%, p < .05) and lingual aspect (6.7% vs. 16.5%, p < .05% and 8.9% vs. 16.5%, p < .05). No statistically significant results were found regarding periodontal parameters PPD, BOP, PI, and REC. No difference was found between groups regarding patient satisfaction.

CONCLUSION

RF seems to have an additive effect on preventing calculus accumulation on the buccal aspect of anterior mandibular teeth at 1 month. Nevertheless, at 3 months, no difference between the toothbrushes is seen regarding calculus formation and maintaining periodontal health (ClinicalTrials.gov, Identifier NCT04640857).

Pulsed Electromagnetic Fields Disrupt Staphylococcus epidermidis Biofilms and Enhance the Antibiofilm Efficacy of Antibiotics

Staphylococcus epidermidis is implicated in a multitude of human infections and is one of the major causes of clinical infections in hospitals, especially at surgical sites and on indwelling medical devices, such as orthopedic implants. These infections are especially dangerous because of the S. epidermidis propensity to form biofilms, which increases resistance to antibiotics and the natural immune response. This study investigated pulsed electromagnetic fields (PEMF) as a potential treatment to combat such infections, as PEMF exposure was expected to disrupt the electrostatic forces that adhere staphylococcal cells to surfaces and to one another. To test the effect of PEMF on biofilms, S. epidermidis cultures were exposed to PEMF at various durations either during the growth phase or after a full biofilm had formed. In addition, cells were exposed to PEMF and concomitant antibiotic treatment. Biofilm viability was quantified by both crystal violet and alamarBlue assays and scanning electron microscopy. The results demonstrated that PEMF significantly inhibited biofilm formation and disrupted preformed biofilms in vitro while also showing synergistic biofilm inhibition when combined with antibiotics. These combined results indicate that PEMF should be considered a promising novel technique for treating S. epidermidis biofilm infections and undergo further testing in vivo. IMPORTANCE Antibiotic resistance and biofilm infections are major issues in health care because of the lack of a successful treatment modality and poor patient outcomes. These infections are a particular issue following orthopedic surgery or trauma wherein an infection may form on an orthopedic implant or patient's bone. The presented study demonstrates that pulsed electromagnetic fields may be a promising novel treatment for such infections and can overcome the medical challenges presented by biofilm formation. Furthermore, the effects demonstrated are even greater when combining pulsed electromagnetic field therapy with traditional antibiotics.

Characteristics of oral microbiome of healthcare workers in different clinical scenarios: a cross-sectional analysis

The environment of healthcare institutes (HCIs) potentially affects the internal microecology of medical workers, which is reflected not only in the well-studied gut microbiome but also in the more susceptible oral microbiome. We conducted a prospective cross-sectional cohort study in four hospital departments in Central China. Oropharyngeal swabs from 65 healthcare workers were collected and analyzed using 16S rRNA gene amplicon sequencing. The oral microbiome of healthcare workers exhibited prominent deviations in diversity, microbial structure, and predicted function. The coronary care unit (CCU) samples exhibited robust features and stability, with significantly higher abundances of genera such as Haemophilus, Fusobacterium, and Streptococcus, and a lower abundance of Prevotella. Functional prediction analysis showed that vitamin, nucleotide, and amino acid metabolisms were significantly different among the four departments. The CCU group was at a potential risk of developing periodontal disease owing to the increased abundance of F. nucleatum. Additionally, oral microbial diversification of healthcare workers was related to seniority. We described the oral microbiome profile of healthcare workers in different clinical scenarios and demonstrated that community diversity, structure, and potential functions differed markedly among departments. Intense modulation of the oral microbiome of healthcare workers occurs because of their original departments, especially in the CCU.

Prolonged Inhibition of Streptococcus mutans Growth and Biofilm Formation by Sustained Release of Chlorhexidine from Varnish Coated Dental Abutments: An in Vitro Study

Background

It has been confirmed that bacterial biofilm covering dental implants is the main microbial source causing preimplant infectious and inflammatory diseases. The purpose of this study was to evaluate the antibacterial/antibiofilm effect of chlorhexidine, incorporated into a sustained-release varnish of chlorhexidine (SRV-CHX) coating, on dental abutments.

Materials and Methods

Three kinds of dental abutments were used: a high-performance semi-crystalline engineering thermoplastic polyetheretherketone (PEAK) healing abutment, a titanium healing abutment, and a titanium permanent abutment. These abutments were coated with SRV-CHX or SRV-placebo and exposed daily to fresh cultures of Streptococcus mutans. The effect of SRV-CHX on S. mutans growth on agar plates was studied by measuring the zone of inhibition (ZOI) around each tested abutment every day for a period of 36 days. Biofilm formation on the SRV-CHX/placebo-coated abutments was detected using confocal laser scanning microscopy (CLSM) and high-resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), and monitored by crystal violet (CV) staining.

Results

SRV-CHX-coated abutments 2 and 3 were able to inhibit S. mutans growth for 34 days, while abutment 1 inhibited growth for 32 days. Abutment-associated biofilm formation was notably inhibited by SRV-CHX coating after 13 days of incubation with S. mutans. Finally, the biofilm formed around SRV-CHX-coated abutments was completely inhibited up to 12 days of abutment exposure to S. mutans.

Conclusion

Coating of dental abutments with SRV-CHX demonstrated long-term effective inhibition of S. mutans growth and biofilm formation on the abutment surface.

Polymicrobial biofilms related to dental implant diseases: unravelling the critical role of extracellular biofilm matrix

Biofilms are complex tri-dimensional structures that encase microbial cells in an extracellular matrix comprising self-produced polymeric substances. The matrix rich in extracellular polymeric substance (EPS) contributes to the unique features of biofilm lifestyle and structure, enhancing microbial accretion, biofilm virulence, and antimicrobial resistance. The role of the EPS matrix of biofilms growing on biotic surfaces, especially dental surfaces, is largely unravelled. To date, there is a lack of a broad overview of existing literature concerning the relationship between the EPS matrix and the dental implant environment and its role in implant-related infections. Here, we discuss recent advances in the critical role of the EPS matrix on biofilm growth and virulence on the dental implant surface and its effect on the etiopathogenesis and progression of implant-related infections. Similar to other biofilms associated with human diseases/conditions, EPS-enriched biofilms on implant surfaces promote microbial accumulation, microbiological shift, cross-kingdom interaction, antimicrobial resistance, biofilm virulence, and, consequently, peri-implant tissue damage. But intriguingly, the protagonism of EPS role on implant-related infections and the development of matrix-target therapeutic strategies has been neglected. Finally, we highlight the need for more in-depth analyses of polymicrobial interactions within EPS matrix and EPS-targeting technologies' rationale for disrupting the complex biofilm microenvironment with more outstanding translation to implant applications in the near future.