Cathepsin C in health and disease: from structural insights to therapeutic prospects.

Cathepsin C (CTSC) is a lysosomal cysteine protease constitutively expressed at high levels in the lung, kidney, liver, and spleen. It plays a key role in the activation of serine proteases in cytotoxic T cells, natural killer cells (granzymes A and B), mast cells (chymase and tryptase) and neutrophils (cathepsin G, neutrophil elastase, proteinase 3) underscoring its pivotal significance in immune and inflammatory defenses. Here, we comprehensively review the structural attributes, synthesis, and function of CTSC, with a focus on its variants implicated in the etiopathology of several syndromes associated with neutrophil serine proteases, including Papillon-Lefevre syndrome (PLS), Haim-Munk Syndrome (HMS), and aggressive periodontitis (AP). These syndromes are characterized by palmoplantar hyperkeratosis, and early-onset periodontitis (severe gum disease) resulting in premature tooth loss. Due to the critical role played by CTSC in these and several other conditions it is being explored as a potential therapeutic target for autoimmune and inflammatory disorders. The review also discusses in depth the gene variants of CTSC, and in particular their postulated association with chronic obstructive pulmonary disease (COPD), COVID-19, various cancers, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, sudden cardiac death (SCD), atherosclerotic vascular disease, and neuroinflammatory disease. Finally, the therapeutic potential of CTSC across a range of human diseases is discussed.

The Potential Effect of Periodontal Disease on the Development of Metabolic Syndrome: A 10-Year Observational Study in a Thai Adult Cohort.

AIM: As data are sparse on the long-term association between periodontal diseases and development of metabolic syndrome (MetS), we investigated their relationship in a Thai cohort over a 10-year observational period. METHODS: Medical records and data on periodontal assessments of 2161 employees of the Electricity Generating Authority of Thailand collected at two time points, 2003 and 2013, were used. Experienced periodontists used standard national and international criteria to define periodontitis and MetS. The impact of baseline periodontitis on subsequent MetS incidence and its components was evaluated using regression analyses. RESULTS: The severity and extent of periodontitis significantly predicted MetS incidence over a decade, with a higher incidence of MetS in individuals with poorer periodontal health. A single percentage increase in the periodontitis extent raised the risk of MetS incidence by 0.4% and the risk of developing individual components of MetS by 0.2%. Independent of periodontal health, age of an individual emerged as a factor impacting MetS development. CONCLUSION: This study highlights the potential effect of the severity and extent of periodontitis on the increased incidence and progression of MetS. Hyperglycaemia and hypertension were the two MetS components most significantly affected by the existence of periodontitis.

Tooth agenesis related to a novel KDF1 variant: A case report and literature review.

OBJECTIVES: To investigate the role of Keratinocyte Differentiation Factor 1 (KDF1) in ectodermal dysplasia (ED) and nonsyndromic tooth agenesis (NSTA) and perform a literature review. METHODS: Genome sequencing was used to identify genetic variants in a Thai, NSTA proband and validated through Sanger sequencing. Pathogenicity was assessed using ACMG guidelines, MetaRNN and AlphaMissense. A comprehensive review of KDF1/NSTA cases informed genotype-phenotype analysis of the proband. RESULTS: The proband revealed multiple missing teeth, caries and extensive periodontal disease. Deep phenotyping showed no signs of ED beyond tooth agenesis. The identified novel KDF1 variant, p.Ile243Leu, was classified as 'likely pathogenic' by ACMG and predicted as 'detrimental' by MetaRNN and AlphaMissense analyses. A total of 14 reviewed KDF1 cases revealed ED-associated variants (3 variants in 8 patients) clustering in the region of amino acids 251-275, within the DUF4656 domain, while NSTA-causing variants (4 variants in 6 patients) were typically found in amino- or carboxy-termini to this region. KDF1/NSTA cases exhibited an average of 15 missing teeth, with a higher prevalence in the mandible. CONCLUSION: This study identifies a novel KDF1 variant-related NSTA in Thai people. The genotype-phenotype correlates suggest a distinctive pattern and tooth agenesis of KDF1-related NSTA.

The association between interdental cleaning and periodontitis in an urban Thai adult cohort: a cross-sectional study.

BACKGROUND: Plaque biofilm is a major etiologic factor of periodontitis, and its effective removal prevents or ameliorates the disease. However, toothbrushing alone does not sufficiently clean the interdental area, and additional interdental cleaning is required to completely remove the plaque from this locale. This cross-sectional study aimed to assess the association of interdental cleaning on the prevalence of periodontitis in a large urban Thai adult cohort. METHODS: Interdental cleaning data were retrieved from a dental survey of 1,743 employees of the Electricity Generating Authority of Thailand (EGAT) in 2019. The Centers for Disease Control and Prevention/American Association of Periodontology (CDC/AAP) periodontal case definitions were applied. The participants were subdivided into two groups as those with or without periodontitis depending on their oral health status assessed by calibrated professional examiners. The proportion of subjects who performed interdental cleaning was assessed through a self-reported questionnaire by frequency (daily/ ≥ 1 per week/ none) and profile (correct/ incorrect) of interdental cleaning. Then, the association between interdental cleaning and periodontitis was calculated using logistic regression analysis controlling for the common risk factors of periodontitis such as age, sex, education, smoking, and diabetes. RESULTS: Participants who performed interdental cleaning on a daily basis and ≥ 1 per week were 27.5% (95% CI: 25.4, 29.6) and 29.1% (95% CI: 27.0, 31.3), respectively while the remainder did not practice. Of those who used interdental cleaning, about one-half focused on sites with food impaction. There was a significant 44% lower prevalence of periodontitis (adjusted odds ratio of 0.56 (95%CI: 0.40, 0.79) in the cohort with a frequent and correct group. CONCLUSIONS: Our data indicate an inverse association between interdental cleaning and periodontitis, particularly in those who routinely adhered to it. Regular interdental cleaning is likely to have a salutary effect on oral health. TRIAL REGISTRATION: The study was registered retrospectively in Thai Clinical Trials Registry, Registration number: TCTR20240817005, on 17 Aug 2024 ( https://www.thaiclinicaltrials.org ).

The first report of the presence of collagen X in mammalian dentinal matrix.

Collagen X is an extracellular matrix protein, usually found in the hypertrophic cartilage destined to be mineralized. It is intimately associated with the mineralization process of the mammalian hard tissues, and particularly, regulating the compartmentalization of matrix components. Despite the fact that the dentine of the tooth is highly mineralized, there are no previous reports to indicate the presence of collagen X in this connective tissue. Here we report, for the first time, its presence in mammalian dentine based on micromorphological and immunohistochemical data. We hypothesize that the collagen X in dentine may in the long term arrest the progression of the mineralization front towards the soft tissue components of the pulp that are not destined to be mineralized.

Emerging and future strategies in the management of recalcitrant Candida auris.

Candida auris is an emerging, multi drug resistant fungal pathogen that has caused infectious outbreaks in over 45 countries since its first isolation over a decade ago, leading to in-hospital crude mortality rates as high as 72%. The fungus is also acclimated to disinfection procedures and persists for weeks in nosocomial ecosystems. Alarmingly, the outbreaks of C. auris infections in Coronavirus Disease-2019 (COVID-19) patients have also been reported. The pathogenicity, drug resistance and global spread of C. auris have led to an urgent exploration of novel, candidate antifungal agents for C. auris therapeutics. This narrative review codifies the emerging data on the following new/emerging antifungal compounds and strategies: antimicrobial peptides, combinational therapy, immunotherapy, metals and nano particles, natural compounds, and repurposed drugs. Encouragingly, a vast majority of these exhibit excellent anti- C. auris properties, with promising drugs now in the pipeline in various stages of development. Nevertheless, further research on the modes of action, toxicity, and the dosage of the new formulations are warranted. Studies are needed with representation from all five C. auris clades, so as to produce data of grater relevance, and broader significance and validity. LAY SUMMARY: Elimination of Candida auris that causes deadly infections to susceptible individuals is extremely challenging due to the lack of effective treatment options. Promising, new antifungal agents and strategies are being developed and further refinement will facilitate their clinical use in the near future.

Tea extracts inhibit the attachment of streptococci to oral/dental substrata by reducing hydrogen bonding energies.

Previous work in the authors' lab demonstrated that tea extracts significantly suppressed streptococcal colonization of abiotic substrata by coating the bacterial cell surfaces with tea components. In this study, the physico-chemical mechanisms by which the tea coating inhibits cellular attachment are demonstrated. The changes in the cell surface physico-chemical properties of streptococci, induced by tea extracts, were measured. Using these results, surface interaction energies were calculated between streptococcal cells and hard surfaces (glass, stainless steel, hydroxyapatite and titanium) within the cellular attachment system exploiting the extended Derjaguin-Landau-Verwey-Overbeek theory. The net energy outcomes were compared with experiment results of attachment assays to validate the predictability of the model. The results showed that the tea extracts inhibited the attachment of the bacteria by 11.1%-91.5%, and reduced the interaction energy by 15.4%-94.9%. It was also demonstrated that the abilities of the bacteria to attach to hard surfaces correlated well with their net interaction energies. The predominant interaction in the systems was found to be hydrogen bonding. In conclusion, tea extracts suppress streptococcal attachment to hard substrata by limiting the formation of hydrogen bonds.

Coronavirus disease 2019 (COVID-19) vaccines: A concise review.

The development of a successful vaccine against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the agent of coronavirus disease 2019 (COVID-19), in an unmatched period of ten months, is a tribute to human ingenuity in the face of a vicious pandemic. A return to pre-pandemic "normalcy" depends on the successful delivery of the vaccine to a majority (~70%) so as to develop herd immunity critical to arrest the community spread of infection. Vaccination against COVID-19 is particularly important for dentistry as the dental team works in an environment replete with aerosol-generating procedures (AGP) that facilitate virus spread. Hence, a COVID-19 vaccine is likely to be an obligatory requirement for the dental practice, and the latest addition to the extensive list of vaccines required for dental professionals for the safe delivery of dental care. Here, we review the currently available major candidate vaccines against SARS-CoV-2 and their benefits and risks. These include the vaccines developed on next-generation platforms (mRNA, DNA, and viral vector vaccines), and the classic platforms (the live-attenuated virus, and the protein subunit vaccines) The review concludes with a summary of impending issues and challenges facing the provision of COVID-19 vaccines for all stakeholders in dentistry.

Attributes of dysgeusia and anosmia of coronavirus disease 2019 (COVID-19) in hospitalized patients.

OBJECTIVES: While chemosensory dysfunctions, dysgeusia and anosmia/hyposmia, are recognized as distinctive symptoms of COVID-19, their temporality of presentation and association with the patient age, gender, disease severity, and comorbidities has been sparsely studied. Hence, we evaluated the latter associations of chemosensory dysfunction, in hospitalized COVID-19 patients in the United Arab Emirates (UAE). MATERIALS AND METHODS: Information on chemosensory dysfunction and history of chronic systemic comorbidities, if any, was obtained from 149 COVID-19 patients in an infectious disease hospital in UAE, using their medical records, as well as from a face-to-face questionnaire survey. Additionally, a modified SNOT-22 questionnaire that measures disease-specific quality of life in patients with upper respiratory tract affections was also administered. RESULTS: Chemosensory dysfunction was reported by 94.6% of the cohort, and anosmia with dysgeusia was significantly more in males than females with severe COVID-19. Males with moderate COVID-19 and systemic comorbidities were more likely to present with chemosensory dysfunction in comparison with females. SNOT-22 questionnaire revealed that nasal blockage and runny nose were more prevalent in mild/moderate, than in the severe, state of COVID-19. CONCLUSION: Our data confirm the commonality of chemosensory dysfunction during COVID-19 progression, and the significantly more pronounced combined dysfunction in males with severe COVID-19, and comorbidities.

Dental pedagogy in the 'new normal' COVID-19 era: a transition template of teaching protocols.

AIMS: Delivery of clinical dental education, as opposed to clinical medicine, is particularly challenging due to the obligatory aerosol-generating procedures (AGPs) used in dentistry, which are known to facilitate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, using AGPs and working in close proximity to patients for extended periods in dental hospital/university settings with multiple teaching clinics have been a formidable prospect for all stake holders. Therefore, several professional and governmental organizations have promulgated variations of infection control guidelines for general practice dentistry in the pandemic era to mitigate SARS-CoV-2 transmission. MATERIALS AND METHODS: In the absence of unified guidelines for modified infection control/clinical procedures for dental education. We implemented a clinical protocol template and modified operating procedures (MOP) for teaching clinical dentistry to fit the infection control requirements during the pandemic/post-pandemic period at the Sharjah University, College of Dentistry, UAE. MOPs ranged from various engineering control measures (e.g., negative-pressure ventilation systems in operatories) to administrative control measures featuring post-procedure fallow periods of treatment-abeyance between patient sessions. RESULTS: The new MOPs for clinical dentistry in the COVID-19 pandemic era, trialled in a UAE dental teaching hospital, have successfully eliminated infection transmission amongst the students, clinicians, ancillary staff, or attending patients, thus far. CONCLUSIONS: The proposed MOPs that complement the standard operating protocols in clinical dentistry were an attempt to mitigate nosocomial infection transmission and protect four different groups of stakeholders, i) the patients, ii) the dental students, iii) the clinical academics, and iv) the para-dental personnel/assistants. Due to the endemicity of the COVID-19 in many regions of the World, the suggested MOPs need periodic review and revision, to fit the emerging data on the disease. Finally, as there are no studies to date comparing the relative efficacy of the MOPs in various dental academic institutions, there is an urgent need for future workers to address this issue.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) viral positivity and their burden in saliva of asymptomatic carriers - a systematic review and meta-analysis.

AIMS: The coronavirus disease 2019 (COVID-19) due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can present either as an asymptomatic carrier state or an acute respiratory disease, with or without severe pneumonia. The asymptomatic carriers are a challenge for the dental profession as the infection could be transmitted via virus-laden, and saliva in dental settings through aerosol-generating procedures (AGPSs). The aim of this review was to perform a systematic review of SARS-CoV-2 in the saliva of asymptomatic individuals. MATERIALS AND METHODS: PubMed, Google scholar, and MedRxiv databases were searched between and a systematic review and meta-analysis of the available data were performed to assess the viral burden in the saliva of asymptomatic carriers of SARS-CoV-2. All investigators of the included studies used qRT-PCR to detect SARS-CoV-2 and yield quantitative data (the Ct values) appertaining to the viral load. RESULTS: A total of 322 records in the English literature were identified, and eight studies with 2642 SARS-CoV-2-positive and asymptomatic individuals were included in the final analysis. Of these, 16.7% (95% CI: 11-23%) yielded SARS-CoV-2-positive saliva samples in comparison to 13.1% (95% CI: 12-17%) of the respiratory specimens (nasopharyngeal or nose-throat swabs). CONCLUSION: As approximately 1 in 5 to 1 in 10 asymptomatic individuals harbour SARS-CoV-2 in either saliva or respiratory secretions, our results highlight the need for continued vigilance and the critical importance of maintaining strict, additional infection control regimens for the foreseeable future to mitigate the potential risks of COVID-19 transmission in dentistry.

Facial protection in the era of COVID-19: A narrative review.

We live in extraordinary times, where COVID-19 pandemic has brought the whole world to a screeching halt. Tensions and contradictions that surround the pandemic ridden world include the availability, and the lack thereof, various facial protection measures to mitigate the viral spread. Here, we comprehensively explore the different types of facial protection measures, including masks, needed both for the public and the healthcare workers (HCW). We discuss the anatomy, the critical issues of disinfection and reusability of masks, the alternative equipment available for the protection of the facial region from airborne diseases, such as face shields and powered air-purifying respirators (PAPR), and the skin health impact of prolonged wearing of facial protection by HCW. Clearly, facial protection, either in the form of masks or alternates, appears to have mitigated the pandemic as seen from the minimal COVID-19 spread in countries where public mask wearing is strictly enforced. On the contrary, the healthcare systems, that appear to have been unprepared for emergencies of this nature, should be appropriately geared to handle the imbalance of supply and demand of personal protective equipment including face masks. These are two crucial lessons we can learn from this tragic experience.

Overview of transnational recommendations for COVID-19 transmission control in dental care settings.

On 11 March 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS-CoV-2 transmission is aerosol/droplet spread, and by contacting virus-contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols is produced, as well as the close proximity of dentists and patients during treatment, dentists and allied health staff are considered the highest risk health professional group for acquiring SARS-CoV-2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS-COV-2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID-19, in the post-pandemic era.

The efficacy of bio-aerosol reducing procedures used in dentistry: a systematic review.

BACKGROUND AND OBJECTIVE: Bio-aerosols, are routinely generated and airborne in clinical dentistry due to the operative instrumentation within an oral environment bathed in salivary organisms. SARS-CoV-2 transmission being responsible for the current pandemic, appears through airborne aerosols and droplets, thus, there has been an intense focus on such aerosol-generating procedures, and their reduction. Hence the objective of this systematic review was to evaluate available data on three major measures: rubber dam application, pre-procedural oral rinse, and high-volume evacuators (HVE) aimed at reducing bio-aerosols. METHOD: PubMed via Ovid MEDLINE, EBSCO host, Cochrane Library and Web of Science databases were searched between 01 January 1985 and 30 April 2020. RESULTS: A total of 156 records in English literature were identified, and 17 clinical studies with 724 patients included in the final analysis. Eligible articles revealed the inadequacy of three principle approaches used in contemporary dental practice to minimize such bio-aerosols, rubber dam application, pre-procedural oral rinses, and HVE. The latter is an extremely effective method to reduce bio-aerosols in dentistry, although no single method can provide blanket cover. CONCLUSION: Present systematic review indicates that employing combination strategies of rubber dam, with a pre-procedural antimicrobial oral rinse, and HVE may contain bio-aerosols during operative procedures.

Silver diamine fluoride (SDF) used in childhood caries management has potent antifungal activity against oral Candida species.

BACKGROUND: The microbiome of Severe-Early Childhood Caries (S-ECC), is characterized by an ecosystem comprising bacterial and fungal species, with a predominance of Candida species. Hence, an anti-cariogen effective against both bacteria and fungi would be valuable in the management of S-ECC. Here we evaluate the antifungal effect of silver diamine fluoride (SDF) against 35-clinical yeast isolates (Ten-each of C. albicans, C. krusei, C. tropicalis and five C. glabrata strains) from dentinal caries-lesions from S-ECC. RESULTS: Disc-diffusion and time-kill assays as well as MIC50 and MIC90 evaluations against therapeutic concentrations confirmed the broad-spectrum anti-candidal potency of SDF. Ultrastructural images revealed morphologic aberrations of yeast-cell walls on exposure to SDF. All C. krusei and C. glabrata isolates were significantly more sensitive to SDF, relative to the standard antifungal fluconazole. Further, SDF appears to effectively abrogate filamentation of C. albicans even at very low concentrations. CONCLUSIONS: Our data, for the first time, elucidate the antifungal potency of SDF, in addition to its known antibacterial activity, in the management of S-ECC.

Interplay between oral immunity in HIV and the microbiome.

This Basic Science Workshop addressed the oral microbiome. At the 7th World Workshop on Oral Health & Disease in HIV/AIDS in India in 2014, some aspects of the human microbiome were discussed, and research questions formulated. Since that time, there have been major advances in technology, which have stimulated a number of publications on many aspects of the human microbiome, including the oral cavity. This workshop aimed to summarize current understanding of the "normal" microbiome of the oral cavity compared to that during HIV infection, and how oral immune factors and other clinical variables alter or control the oral microbiome. An important question is whether successful treatment with anti-retroviral therapy, which leads to a significant drop in viral loads and immune reconstitution, is associated with any change or recovery of the oral microbiome. Additionally, the workshop addressed the issue of which parameters are most appropriate/correct to evaluate the oral microbiome and how clinically relevant are shifts/changes in the oral microbiome. The workshop evaluated current knowledge in five research areas related to five basic questions and identified further topics where further research is required.

Strategic implementation of dental infection control in resource-poor jurisdictions during COVID-19 pandemic: a perspective from South Africa.

BACKGROUND: The coronavirus disease-19 (COVID-19) pandemic caused by the severe acute respiratory syndrome Coronavirus -2 is unceasing, and the consensus is that the dental profession has to co-exist with this vicious foe for the foreseeable future. Dental professionals in resource poor countries, as opposed to those in developed countries, face additional challenges due to the lack of personal protective equipment, and chronic infrastructural impediments extant in such jurisdictions, such as regular and chronic interruptions to electricity and water supplies. OBJECTIVES: To address this new 'normal' which dictates that dentistry has to 'adapt and adopt' in order to deliver care to the needy, particularly in resource poor nations, whilst care deliverers take appropriate precautionary measures to obviate cross infection. METHODS: A review was preformed of the challenges to delivery of infection control measures in dentistry in resource meagre settings, and practical interventional measures proposed to mitigate these challenges, taking South Africa as a case study. RESULTS: In reality, optimal infection control measures cannot be implemented in delivering dental care in resource poor settings, a challenge that has been ill addressed by the relevant authoritative bodies. A re-adaptation of infection control guidelines that could be simply implemented in such settings has been formulated. CONCLUSION: We present practical infection control guidelines to lessen the burden of dental professionals in resource poor countries who dispense treatment under trying circumstance. The strategic infection control measures, including engineering and administrative controls outlined could be applicable in jurisdictions with a diminished capacity to respond to local, regional or national infection control guide-lines, due to financial, regulatory, or other infrastructural resource deficiencies.

Sudden onset, acute loss of taste and smell in coronavirus disease 2019 (COVID-19): a systematic review.

BACKGROUND: Early detection, isolation and management of COVID-19 are crucial to contain the current pandemic. US Centers for Disease Control and Prevention (CDC) recently included 'sudden loss of taste (dysgeusia/ageusia) and smell (anosmia/hyposmia)' as symptoms of COVID-19. If indeed these symptoms are reliable and specific forerunner symptoms of COVID-19, then it may facilitate detection and containment of the disease. Hence, we systematically evaluated the contemporary evidence on dysgeusia and anosmia as trigger prodromal symptoms, and their prevalence in COVID-19 patients. METHODS: Ovid MEDLINE, EBSCO host and Web of Science databases were searched between 25 December 2019 and 30 May 2020. RESULTS: Of the 13 identified records, eight studies, totalling 11,054 COVID-19 patients, were included, as per the selection criteria. Eligible articles reflected research conducted mostly in the European community, as well as China, the US and Iran. In total, anosmia and dysgeusia symptoms were present in 74.9% and 81.3% ambulatory as well as hospitalized, mild-to-severe cases of COVID-19 patients, respectively. The European, US and Iran data indicate olfactory and gustatory symptoms appear prior to general COVID-19 symptoms in 64.5% and 54.0% of the patients, respectively. CONCLUSIONS: To our knowledge, this is the first systematic review analysing the meager data based on the prevalence of chemosensory dysfunction in COVID-19. Critical analysis of such macro-data, as and when available, is essential to evaluate their utility as harbingers of COVID-19 onset, and to establish clinical practice guidelines both in dentistry and medicine.

The effectiveness and efficacy of respiratory protective equipment (RPE) in dentistry and other health care settings: a systematic review.

OBJECTIVE: The global pandemic of coronavirus disease-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is the latest hazard facing healthcare workers (HCW) including dental care workers (DCW). It is clear that the major mode of SARS-CoV-2 transmission is the airborne route, through inhalation of virus-infested aerosols and droplets. Several respiratory protection equipment (RPE), including masks, face shields/visors, and respirators, are available to obviate facial and conjunctival contamination by microbes. However, as their barrier value against microbial inhalation has not been evaluated, we systematically reviewed the data on the effectiveness and efficacy of facemasks and respirators, including protective eyewear, with particular emphasis on dental healthcare. MATERIAL AND METHODS: PubMed, MEDLINE, the Cochrane Library, and Embase databases were searched between 01January 1990 and 15 May 2020. RESULTS: Of 310 identified English language records, 21 were included as per eligibility criteria. In clinical terms, wearing layered, face-fitting masks/respirators and protective-eyewear can limit the spread of infection among HCWs. Specifically, combined interventions such as a face mask and a face shield, better resist bioaerosol inhalation than either alone. The prolonged and over-extended use of surgical masks compromise their effectiveness. CONCLUSIONS: In general, RPE is effective as a barrier protection against aerosolized microbes in healthcare settings. But their filtration efficacy is compromised by the (i) inhalant particle size, (ii) airflow dynamics, (iii) mask-fit factor, (iv) period of wear, (v) 'wetness' of the masks, and (vi) their fabrication quality. The macro-data presented here should inform policy formulation on RPE wear amongst HCWs.

Clinical efficacy and the antimicrobial potential of silver formulations in arresting dental caries: a systematic review.

BACKGROUND: The use of silver-formulation as microbicide to arrest dentinal caries is gaining popularity. The primary objective of the present appraisal was to systematically review the clinical (in vivo) applications and antimicrobial potential of silver-containing formulations in arresting dentinal caries. Our secondary aim was to sum up the available in vitro applications of silver-containing formulations against cariogenic microbes isolated from dentine lesions. METHODS: Ovid MEDLINE, EBSCO host, Web of Science, and Cochrane Library databases was searched between January 2009-May 2019. RESULTS: In vivo: We observed conflicting evidence of antimicrobial efficacy of SDF on a diverse array of microbial taxa present in carious dentine of primary and permanent teeth. Moreover, there is insufficient evidence on the application of AgNP-fluoride as an effective microbicidal against cariogens of dentine lesions. In vitro: We found a good evidence of microbicidal efficacy of silver diamine fluoride (SDF) on selective cariogenic microbes in human dentine model. Additionally, a good evidence was noted of in vitro application of silver nanoparticles (AgNPs) as a useful microbicidal against S. mutans adhesion, growth and subsequent biofilm formation in human dentine models. CONCLUSIONS: Taken together, in vitro evidence indicates the promising antimicrobial potential of silver-based formulations (SDF and nanosilver) against the predominant cariogenic flora, particularly from dentine lesions. Post-treatment clinical data of either the bactericidal and bacteriostatic effects of SDF or nanosilver are sparse. Furthermore, the current understanding of the specific size, concentration, antimicrobial mechanisms, and toxicological aspects of nano-silver compounds is inadequate to draw firm conclusions on their clinical utility.