Could light be a broad-spectrum antimicrobial?

DESIGN: A review on antimicrobial resistance mechanisms discussing the main light-based antimicrobial approaches including ultraviolet light (UV), antimicrobial photodynamic therapy (aPDT), and antimicrobial blue light (aBL). AIM: To describe antimicrobial resistance mechanisms and to present potential light-based alternatives to conventional antimicrobials. METHODS: The paper was divided into different topics, starting with an approach to antimicrobial resistance mechanisms. Subsequently, emphasis was placed on innovative light-based antimicrobials approaches, including aBL, UV, and aPDT. RESULTS: The review suggests that blue light (400-470 nm) acts on endogenous porphyrins with peak absorption at 405 nm, thus not requiring the administration of photosensitizers, to trigger antimicrobial effects. In this regarding, the direct effect of aBL could be attributed to both the generation of reactive oxygen species (ROS), which induces microbicidal effects, and the inactivation of bacterial defense mechanisms. In turn, blue light combined with curcumin has been used in the treatment of dental infections. Otherwise, green light (495-570 nm) associated with the photosensitizer Rose Bengal has shown promising results both in wound closure due to the induction of additional collagen cross-link formation and in reducing the viability of Pseudomonas aeruginosa. Red light (620-750 nm) is the wavelength most commonly used in aPDT, presenting superior tissue penetration capability compared to blue and green light. Both red and infrared light act directly as photobiomodulation agents, promoting tissue repair with greater penetration depth for the infrared spectrum. Conversely, red light combined with methylene blue is the most commonly used technique in the treatment of localized infections. Meanwhile, infrared light associated with indocyanine green acts as a photothermal and photosensitizing agent, promoting thermal damage and production of ROS. Ultraviolet lights UVA, UVB, and UVC (200-400 nm) have antimicrobial potential related to inducing changes in DNA and generating both ROS and singlet oxygen. Furthermore, light can enhance the efficacy of traditional antimicrobial agents by deactivating microbial resistance, both through increasing the permeability of the cell membrane and by inhibiting the efflux pump and ß-lactamases of the bacteria. CONCLUSIONS: The antimicrobial potential of light is extensive; however, there is a limitation regarding the depth of penetration of certain wavelengths into infected areas. Furthermore, there is a need for additional studies to determine the safety and efficacy of various approaches using light at its different wavelengths.

What is the potential of antibacterial, antiviral and antifungal photodynamic therapy in dentistry?

DESIGN: A review of the principal clinical applications of antimicrobial photodynamic therapy (aPDT) in dentistry. AIM: To provide an overview of clinical applications and future perspectives of aPDT in dentistry. METHODS: A comprehensive search was conducted on PubMed, Web of Science, Scopus, and Embase up to September 2022, where only data from randomized clinical trials were included. In vitro studies, animal studies, literature reviews, and duplicate articles were excluded from the review. Out of a total of 1042 references initially identified, only 89 studies were included in the review. Six main oral conditions for which aPDT has been used were identified: periodontal and peri-implant diseases, endodontics, bacterial plaque, caries, and fungal and viral infections. RESULTS: The review suggests that aPDT can be used as an effective complementary treatment for reducing pathogenic microorganisms in bacterial plaque; carious lesions; and periodontal, peri-implant, endodontic, fungal, and viral infections. CONCLUSIONS: Despite the efficacy of aPDT against different types of microorganisms, there are no specific irradiation parameters for its respective photosensitizers due to the significant heterogeneity of clinical trials. Therefore, more studies are needed to determine irradiation protocols and development of new photosensitizers to improve the safety and efficacy of aPDT.

Omnivore and vegetarians show similar body composition and skin physiology across body regions-A comparative analysis.

BACKGROUND: Skin physiology seems to be influenced by dietary choices and body composition, although links between these factors remain poorly characterised. In the present manuscript, we elaborate on the potential relationships among food groups, body composition and skin physiology in omnivores and vegetarians. MATERIAL AND METHODS: This cross-sectional observational study involved 181 participants, 129 omnivores and 52 vegetarians. The main functions of the skin measured in our laboratory were transepidermal water loss, deep and superficial epidermal hydration, skin elasticity, and carotenoid content. Skin variables obtained from different body regions were made comparable by a new Proportional Skin Index calculated to respect their relative representativity. RESULTS: No statistical differences were found when comparing both groups' body composition and skin variables from different body regions, with the exception of the skin carotenoid content significantly higher in the vegetarian group (p < 0.001). CONCLUSION: Although dietary patterns significantly differed between groups, with vegetarians consuming fewer animal-derived products and more plant-based foods, multiple linear regression analysis revealed no differences or association between the dietary pattern and the skin physiology. These findings highlight the need for further research to elucidate the specific impact of diet and food groups and body composition on skin physiology.

What is the science underpinning the prescription of antibiotics in dentistry?

DESIGN: A critical review on the use of antimicrobials in dentistry. AIM: To provide a general overview of the use of antimicrobials in dentistry. METHODS: The paper was divided into different topics, starting with an approach to understanding both commensal and pathogenic oral microbiota. Subsequently, emphasis was placed on the main categories of antibiotics used in dentistry (ß-lactams, tetracyclines, macrolides, lincosamides, nitroimidazoles and quinolones), and the basis for their prescription. Finally, the implications between systemic diseases and the use of orally-administered antibiotics are presented. RESULTS: The study suggests that an adequate medical history can minimize the risk of systemic adverse effects, unwanted drug interactions, and allergies related to the use of antibiotics. In this regard, when facing a potential history of allergy to a particular group of antibiotics, the prescription of a different group is mandatory. In most indications, ß-lactam antibiotics represent the first-choice in dentistry. Moreover, a short-term prescription of antibiotics when treating acute oral infections is recommended. The use should be extended for 2 to 3 days following the resolution of the infection, with an average duration of 6 days in order to prevent the development of antibiotic resistance. CONCLUSIONS: Oral infections should be managed with interventions aiming at the elimination/reduction of the associated pathogens. Furthermore, inadequate prescription of antibiotics can lead to potential risks to the patient such as allergy, adverse effects, and development of microbial resistance.

How safe is off-label use of imiquimod in oral lesions?

DATA SOURCES: A comprehensive search was conducted on PubMed and Embase, adhering to the principles outlined in the PRISMA Extension for Scoping Reviews (PRISMA-ScR). The search strategy was subsequently registered on PROSPERO. STUDY SELECTION: Articles were chosen based on an analysis of titles and abstracts, with no restrictions on publication date, language, or participant age. In vitro studies, animal studies, and literature reviews were excluded from consideration. DATA EXTRACTION AND SYNTHESIS: Clinical trials in humans, case reports, or case series that reported the use of imiquimod for treating conditions in the oral or labial mucosa were included in this study. Results from duplicate articles were excluded from the analysis. RESULTS: Out of a total of 601 references initially identified, only 28 studies were included in the review. These studies were classified based on the use of imiquimod into three groups: potentially malignant disorders and oral cancer, lesions related to HPV, and autoimmune conditions. In all cases presented in the article, there is an occurrence of both local and systemic side effects. CONCLUSIONS: The study elucidated the off-label use of imiquimod in oral pathologies, whether potentially malignant, cancerous, autoimmune, or associated with HPV infection. However, it was observed that further research is warranted for the development of a specific formulation for the oral mucosa, ensuring the drug's sustained presence at its active site of action without interference from saliva and minimizing potential side effects.

Would it really be necessary to use metronidazole as an adjunct in the surgical treatment of periodontitis?

DESIGN: Prospective, parallel, randomized, double-blind, clinical trial. CASE SELECTION: Participants were at least 30 years old, who were systemically healthy, with stages III-IV, grades B-C periodontitis. DATA ANALYSIS: Of the 50 eligible individuals for the study, 40 were divided into 2 equal groups. The test group received doses of 500 mg of metronidazole, while the control group received a placebo, both administered three times a day for 7 days, commencing immediately after periodontal surgery. All patients were followed up at 3-, 6-, 9-, and 12-months post-surgery. The study utilized probing depth, clinical attachment level, bleeding on probing, and plaque index as parameters for determining the outcomes at each assessment. Microbiological samples were collected for the detection and quantification of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia DNA. In order to analyze quantitative variables in a comparison between the test and control groups, Student's t-tests or Mann-Whitney U tests were utilized. For categorical results, chi-square or Fisher tests were employed. For both probing depth and clinical attachment level, repeated measures ANOVA was used. The statistical significance level was set at p ≤ 0.05. RESULTS: The study found statistically significant differences for probing depth (mean difference, MD = 0.31 mm, 95% confidence interval, CI [0.13; 0.49]; p = 0.001) and clinical attachment level (MD = 0.64 mm, 95% CI [0.02; 1.27]; p = 0.044) only 3 months after surgery, with a reduction observed in the test group. However, despite being statistically significant, these results lack clinical relevance. CONCLUSIONS: Although the study found statistically significant results for clinical attachment level (MD = 0.66 mm, 95% CI [0.01; 1.31]; p = 0.045) and probing depth (MD = 0.28 mm, 95% CI [0.09; 0.46]; p = 0.004), these findings do not represent clinically significant gains. Therefore, no evidence was demonstrated to support the use of systemic metronidazole as adjunctive therapy to periodontal surgery.

Studying Erythromelalgia Using Doppler Flowmetry Perfusion Signals and Wavelet Analysis-An Exploratory Study.

Erythromelalgia (EM) is a rare disease, which is still poorly characterized. In the present paper, we compared the hand perfusion of one female EM patient, under challenges, with a healthy control group. Using a laser Doppler flowmeter (LDF) with an integrated thermal probe, measurements were taken in both hands at rest (Phase I) and after two separate challenges-post-occlusive hyperemia (PORH) in one arm (A) and reduction of skin temperature (cooling) with ice in one hand (B) (Phase II). The final measurement periods corresponded to recovery (Phases III and IV). The control group involved ten healthy women (27.3 ± 7.9 years old). A second set of measurements was taken in the EM patient one month after beginning a new therapeutic approach with beta-blockers (6.25 mg carvedilol twice daily). Z-scores of the patient's LDF and temperature fluctuations compared to the control group were assessed using the Wavelet transform (WT) analysis. Here, fluctuations with |Z| > 1.96 were considered significantly different from healthy values, whereas positive or negative Z values indicated higher or lower deviations from the control mean values. Cooling elicited more measurable changes in LDF and temperature fluctuations, especially in higher frequency components (cardiac, respiratory, and myogenic), whereas PORH notably evoked changes in lower frequency components (myogenic, autonomic, and endothelial). No significant Z-score deviations were observed in the second measurement, which might signify a stabilization of the patient's distal perfusion following the new therapeutic approach. This analysis involving one EM patient, while clearly exploratory, has shown significant deviations in WT-derived physiological components' values in comparison with the healthy group, confirming the interest in using cold temperature as a challenger. The apparent agreement achieved with the clinical evaluation opens the possibility of expanding this approach to other patients and pathologies in vascular medicine.

Impacts of smoking on oral health-what is the role of the dental team in smoking cessation?

DATA SOURCES: Electronic searches were conducted on databases (PubMed, EMBASE, and Google Scholar). In addition, websites of national organisations (US Food and Drug Administration, National Cancer Institute, Centres for Disease Control and Prevention, American Dental Association, Office of Disease Prevention and Health Promotion, National Institute on Drug Abuse, Agency for Healthcare Research and Quality) were also searched. STUDY SELECTION: To achieve the objectives of the study, systematic reviews, controlled clinical trials, and observational studies published between October 2021 and February 2022 were considered. DATA EXTRACTION AND SYNTHESIS: This narrative review included articles which investigated the role of Dentistry professionals and their impact on smoking cessation and the effects resulting from tobacco use on oral health. RESULTS: The review revealed that smokers have a significantly higher likelihood of developing oral cancer (95% CI: 3.19-6.77) compared to non-smokers. Passive smokers also have an increased risk (1.51 times) of developing oral cancer (95% CI: 1.20-1.91). Additionally, smokers have an 80% increased risk of periodontitis (RR = 1.82; 95% CI: 1.43-2.31), an 85% worsened periodontal condition (RR = 1.85; 95% CI: 1.5-2.2), and a 36.6% increase in caries prevalence (OR = 1.84; 95% CI: 1.64-2.07). Smoking is also associated with a higher potential for dental implant failure in a dose-dependent manner. Brief educational interventions by the dental team resulted in a smoking cessation rate of 74/1000 individuals versus 27/1000 individuals in the control group. When combined with pharmacological therapy, these interventions may lead to an additional 50 to 70% increase in long-term smoking abstinence. CONCLUSIONS: Smoking is strongly linked to an increased risk of oral cancer, dental caries, implant failure, and periodontal disease. Dental teams play a vital role in identifying and addressing oral pathologies related to smoking and providing necessary care for smoking cessation. Brief educational interventions, either alone or in combination with pharmacotherapy, offer valuable approaches for the dental team to support smoking cessation. However, establishing a comprehensive training and continuing education program is crucial to integrate dental professionals into a multidisciplinary smoking cessation program.

Is there evidence that e-cigarettes promote an increased risk of dental caries?

DATA SOURCES: This study was conducted on a sample of patients who attended the dental clinic at Tufts University School of Dental Medicine, between January 1, 2019 and January 1, 2022. Ethical approval was obtained before commencing the research. STUDY SELECTION: This cross-sectional study was carried out through an electronic search of electronic records. It includes patients aged over 16 years, both electronic cigarette (e-cigarettes) users and non-users, with recorded caries risk assessments. Patients with a history of recreational drug use or lacking a caries diagnosis were excluded. The Caries Management by Risk Assessment (CAMBRA) was utilized to indicate and classify caries risk. DATA EXTRACTION AND SYNTHESIS: Descriptive statistics, multivariate and bivariate analyzes were used to assess the relationship between use of e-cigarettes and caries risk level. SPSS software, Version 26 (IBM) was used in the analysis with significance level set at α = 0.05. RESULTS: Out of a total of 13,216 patients included in the research, 13,080 (99.3%) self-declared as non-users of e-cigarettes, and 136 (0.69%) were e-cigarette users. There was a statistically significant difference (P < 0.001) in caries risk levels between e-cigarette users (6.6% low, 14.3% moderate, and 79.1% high caries risk level) and control group (14.5% low, 25.9% moderate, and 59.6% high caries risk level). CONCLUSIONS: The study provides evidence supporting the notion that e-cigarette users exhibit a high level of caries risk.

Electronic nicotine delivery systems (ENDS): a strategy for smoking cessation or a new risk factor for oral health?

DATA SOURCES: A search was conducted in PubMed and Cochrane Library databases for articles published in English between January 2012 and October 2022. STUDY SELECTION: Articles were selected using both the term "electronic nicotine delivery system" (ENDS), as per the Medical Subject Heading (MeSH), in conjunction with specific oral domains. In vitro studies, animal models, unregistered clinical trials, and articles with conflicts of interest were excluded. DATA EXTRACTION AND SYNTHESIS: Clinical and public health studies comparing ENDS users, smokers, and non-smokers in the context of oral-related diseases were included. Results from duplicate articles were not considered. RESULTS: The study indicates a potential carcinogenic effect due to cytogenotoxicity from intrinsic components of ENDS. However, this does not establish ENDS as an independent risk factor for oral cancer. ENDS use may alter the oral microbiome, leading to increased biofilm adhesion and potential associations with caries, periodontal disease, and peri-implantitis. The wide variety of flavors available in the ENDS market is a significant factor influencing initiation and long-term use by young people. CONCLUSIONS: ENDS users are susceptible to periodontal disease, caries, soft tissue injuries, and changes in tooth and prosthesis coloration. The chemical components in ENDS can induce cellular changes associated with a potential risk of oral cancer. However, more long-term studies are required to fully understand the impact of ENDS use on oral health.

Synthesis of Composites for the Removal of F- Anions.

This work presents the synthesis of amine and ferrihydrite functionalized graphene oxide for the removal of fluoride from water. The synthesis of the graphene oxide and the modified with amine groups is developed by following the modified Hummer's method. Fourier transform infrared spectrometry, X-ray, Raman spectroscopy, thermogravimetric analysis, surface charge distribution, specific surface area and porosity, adsorption isotherms, and the van't Hoff equation are used for the characterization of the synthesized materials. Results show that the addition of amines with ferrihydrite generates wrinkles on the surface layers, suggesting a successful incorporation of nitrogen onto the graphene oxide; and as a consequence, the adsorption capacity per unit area of the materials is increased.

The acute adaptation of skin microcirculatory perfusion in vivo does not involve a local response but rather a centrally mediated adaptive reflex.

Introduction: Cardiovascular homeostasis involves the interaction of multiple players to ensure a permanent adaptation to each organ's needs. Our previous research suggested that changes in skin microcirculation-even if slight and distal-always evoke an immediate global rather than "local" response affecting hemodynamic homeostasis. These observations question our understanding of known reflexes used to explore vascular physiology, such as reactive hyperemia and the venoarteriolar reflex (VAR). Thus, our study was designed to further explore these responses in older healthy adults of both sexes and to potentially provide objective evidence of a centrally mediated mechanism governing each of these adaptive processes. Methods: Participants (n = 22, 52.5 ± 6.2 years old) of both sexes were previously selected. Perfusion was recorded in both feet by laser Doppler flowmetry (LDF) and photoplethysmography (PPG). Two different maneuvers with opposite impacts on perfusion were applied as challengers to single limb reactive hyperemia evoked by massage and a single leg pending to generate a VAR. Measurements were taken at baseline (Phase I), during challenge (Phase II), and recovery (Phase III). A 95% confidence level was adopted. As proof of concept, six additional young healthy women were selected to provide video imaging by using optoacoustic tomography (OAT) of suprasystolic post-occlusive reactive hyperemia (PORH) in the upper limb. Results: Modified perfusion was detected by LDF and PPG in both limbs with both hyperemia and VAR, with clear systemic hemodynamic changes in all participants. Comparison with data obtained under the same conditions in a younger cohort, previously published by our group, revealed that results were not statistically different between the groups. Discussion: The OAT documentary and analysis showed that the suprasystolic pressure in the arm changed vasomotion in the forearm, displacing blood from the superficial to the deeper plexus vessels. Deflation allowed the blood to return and to be distributed in both plexuses. These responses were present in all individuals independent of their age. They appeared to be determined by the need to re-establish hemodynamics acutely modified by the challenger, which means that they were centrally mediated. Therefore, a new mechanistic interpretation of these exploratory maneuvers is required to better characterize in vivo cardiovascular physiology in humans.