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Graphical abstract, Objective Viruses on environmental surfaces, in saliva and other body fluids represent risk of contamination for general population and healthcare professionals. The development of vaccines and medicines is costly and time consuming. Thus, the development of novel materials and technologies to decrease viral availability, viability, infectivity, and to improve therapeutic outcomes can positively impact the prevention and treatment of viral diseases. Methods Herein, we discuss (a) interaction mechanisms between viruses and materials, (b) novel strategies to develop materials with antiviral properties and oral antiviral delivery systems, and (c) the potential of artificial intelligence to design and optimize preventive measures and therapeutic regimen. Results The mechanisms of viral adsorption on surfaces are well characterized but no major breakthrough has become clinically available. Materials with fine-tuned physical and chemical properties have the potential to compromise viral availability and stability. Emerging strategies using oral antiviral delivery systems and artificial intelligence can decrease infectivity and improve antiviral therapies. Significance Emerging viral infections are concerning due to risk of mortality, as well as psychological and economic impacts. Materials science emerges for the development of novel materials and technologies to diminish viral availability, infectivity, and to enable enhanced preventive and therapeutic strategies, for the safety and well-being of humankind.

Neutrophils, cells of the innate immune system, enter the mouth and release factors that are hypothesized to contribute to the degradation of tooth dentin, methacrylate resin composites, and adhesives at the restoration-tooth-dentin interface. The objectives were to characterize neutrophils' degradation towards resin composite, self-etch (SE) and total-etch (TE) adhesives, SE and TE resin-dentin interfaces and to identify proteins that could contribute to the degradation process. Neutrophils' degradation of cured resin composite, and SE and TE adhesives, was quantified by measuring the specific resin degradation by-product, bishydroxy-propoxy-phenyl-propane (bisHPPP), released after 30 days incubation of the materials with the cells. Neutrophils' degradative effect on resin-dentin interfaces was examined by recording the interfacial fracture toughness (FT), and surface analysis of the fracture mode following incubation of SE and TE miniature short-rod (mini-SR) specimens with the cells. Neutrophils increased degradation of polymerized resin composite, and TE adhesive, but not SE adhesive over 30 days (p 0.05). Incubation of SE and TE resin-dentin interfaces with neutrophils led to a reduction in FT over time (p 0.05). The effect was more pronounced for TE interfaces. Neutrophils also affected the fracture mode of SE and TE resin-dentin interfaces. Several proteins that could contribute to the degradative activity of neutrophils, including Neutrophil collagenase (MMP-8), Matrix metalloproteinase- 9 (MMP-9), Cathepsin G, Neutrophil- gelatinase associated lipocalin (NGAL) and Myeloperoxidase, were isolated. The ability of neutrophils to degrade resin, tooth dentin, and reduce the bond strength of resin-dentin interfaces suggest neutrophils' potential role in primary and recurrent caries and dental restoration failure.

This proof-of-concept study aimed at evaluating the proteolytic profile of histatin 1 and 5 in saliva of adolescents with spastic cerebral palsy (CP) with gingivitis.This cross-sectional study included 24 individuals allocated into three groups: G1 (CP with gingivitis; n = 8), G2 (without CP and without gingivitis; n = 8), and G3 (without CP and with gingivitis; n = 8). The gingival index (GI) and simplified oral hygiene index (OHI-S) were evaluated. Whole saliva was collected and used to assess the rate and mode of histatin 1 and 5 at different times. The degradation products were visualized after cationic PAGE and the protein band densities (BDs) were compared with a protein standard. Fragmentation products were collected from the gel, pooled by group and characterized by mass spectrometry. BDs and gingival health parameters were analyzed by One-Way ANOVA or Kruskal Wallis tests, whereas poisson multilevel regression was used to the factors that influenced histatin degradation (α = 5%).Groups G1 and G3 differed significantly on OHI-S, visible biofilm, oral calculus and GI (p0.001). Poisson Regression showed that: 1) CP and gingivitis influenced the degradation of histatin 1 and 5 (p0.05); 2) The degradation of histatin 5 was influenced by age and male sex (p0.05); and 3) GI influenced significantly the degradation of histatin 1 (p0.001). Unique histatin degradation peptides were identified in individuals with gingivitis.These data demonstrated that both the kinetics and pattern of histatins degradation differ according to the gingival health or disease conditions.

Background Dental care settings potentially carry a high risk of cross-infection between dentists and patients and among dental staff due to close contact and use of aerosol-generating procedures. This study aimed to estimate COVID-19 incidence rates among Canadian dentists over a six-month period. Methods We conducted a prospective cohort study of 644 licensed dentists across Canada, from 29th July 2020 to 12th February 2021. An online questionnaire, adopted from WHO Unity Study protocols for assessment of COVID-19 risk among healthcare workers was used to collect self-reported SARS-CoV-2 infection, every four weeks. Bayesian Poisson model was used to estimate the incidence rate and corresponding 95% credible intervals (CI). Results The median age of participants was 47 years, with the majority being female (56.4%) and general practitioners (90.8%). The median follow-up time was 188 days. Six participants reported COVID-19 infection during the study period, giving an incidence rate of 5.10 per 100,000 person-days (95% CI = 1.86 – 9.91 per 100,000 person-days). The incidence proportion was estimated to be 1084 per 100,000 dentists (95% CI = 438 to 2011 per 100,000), while it was 1864 per 100,000 persons (95% CI = 1859 to 1868 per 100,000 persons) in the Canadian population during the same period. Conclusion The low infection rate observed among Canadian dentists over the period July 2020 to February 2021 is reassuring to the dental and general community.

To identify and characterize specific esterases from S. mutans with degradative activity toward methacrylate-based resin monomers.Out of several putative esterases, an esterase encoded in an Open Reading Frame as SMU_118c (The National Center for Biotechnology Information, NCBI), was found to have true hydrolase activities. SMU_118c was cloned, expressed, purified and further characterized for its respective hydrolytic activity towards ester-containing nitrophenyl substrates and the universal resin monomers bis-phenyl-glycidyl-dimethacrylate (bisGMA) and triethyleneglycol dimethacrylate (TEGDMA) at neutral (7.0) or cariogenic (5.5) pH. Mass spectrometry (MS) was used to verify the expression of SMU_118c protein in S. mutans UA159.Similar to the whole cell activity of S. mutans, SMU_118c showed the highest affinity toward para-nitrophenyl acetate (pNPA) and para-nitrophenyl butyrate (pNPB) vs. ortho-nitrophenyl butyrate (oNPB) and butyrylthiocholine iodide (BTC) (p 0.05). The esterase retained 60% of its activity after 21 days and hydrolyzed bisGMA at a higher rate than TEGDMA at both neutral and cariogenic pH (p 0.001), similarly to the predominant human salivary esterase degradative activity. MS confirmed that SMU_118c is an intracellular protein in S. mutans UA159 and expressed under pathogenic (pH 5.5) growth conditions.The similarity in the activity profile to the whole S. mutans bacterial cell, the stability over time at cariogenic pH, the preference to hydrolyze bisGMA and confirmed expression profile suggest that SMU_118c could be a significant contributor to the whole bacterial degradative activity of S. mutans toward the degradation of resin composites, adhesives and the restoration-tooth interface, potentially accelerating restoration's failure.The current study builds upon our highly-cited previous study by Bourbia et al., (JDR, 2013) that reported on that the cariogenic bacterium, S. mutans has esterase-like activities that enable the bacterium to degrade dental composites and adhesives. The current submission is the first to report on the isolation and characterization of the specific esterase activity (SMU_118c) from S. mutans that is a significant contributor to the whole bacterial degradative activity toward the hydrolysis of dental resins. This activity compromises the restoration-tooth interface, increases interfacial bacterial microleakage (Kermanshahi et al., JDR 2010), potentially contributing to the pathogenesis of recurrent caries around resin composite restorations. This represent a significant contribution to the field of biomaterials and their clinical performance.

Protein-protein interaction is a common physiological mechanism for protection and actions of proteins in an organism. The identification and characterization of protein-protein interactions in different organisms is necessary to better understand their physiology and to determine their efficacy. In a previous in vitro study using mass spectrometry, we identified 43 proteins that interact with histatin 1. Six previously documented interactors were confirmed and 37 novel partners were identified. In this tutorial, we aimed to demonstrate the usefulness of the STRING database for studying protein-protein interactions. We used an in-silico approach along with the STRING database (http://string-db.org/) and successfully performed a fast simulation of a novel constructed histatin 1 protein-protein network, including both the previously known and the predicted interactors, along with our newly identified interactors. Our study highlights the advantages and importance of applying bioinformatics tools to merge in-silico tactics with experimental in vitro findings for rapid advancement of our knowledge about protein-protein interactions. Our findings also indicate that bioinformatics tools such as the STRING protein network database can help predict potential interactions between proteins and thus serve as a guide for future steps in our exploration of the Human Interactome.Our study highlights the usefulness of the STRING protein database for studying protein-protein interactions. The STRING database can collect and integrate data about known and predicted protein-protein associations from many organisms, including both direct (physical) and indirect (functional) interactions, in an easy-to-use interface.

Made available in DSpace on 2021-06-25T10:55:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Canadian Institutes of Health Research Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objective: The aim of this in vitro study was to evaluate the effect of statherin and its naturally occurring peptides (DR9-2, DR9, GE-12, IT-32, GQ-19, IP-18) on Candida albicans metabolism and biofilm development. Design: After the killing assay, a peptide pellicle was formed on the bottom of a polystyrene plate at the IC50 of each peptide. Over the peptide pellicle, Candida albicans biofilm (48 h) was grown. The peptides antimicrobial activity after the peptides treatment was evaluated by alamarBlue, total biofilm biomass and colony forming units (CFU) counting. Results: The pellicle with statherin and the peptides (DR9-2, DR9, GE-12, IP-18, GQ-19) was able to reduce he viability of Candida albicans compared to the negative control. They also decreased cell proliferation by 20 % and total biomass. IT-32 showed the highest reduction in cell proliferation and biomass, which was similar to the positive control, histatin 5. Conclusions: These results suggest that the naturally occuring peptides from statherin are able to decrease Candida albicans colonization and biofilm proliferation. Department of Dental Materials and Prosthodontics Araraquara Dental School São Paulo State University UNESP, 1680 Rua Humaitá College of Dentistry University of Saskatchewan, 105 Wiggins Road Department of Physiology Institute of Biomedical Sciences Federal University of Uberlandia, 3Q – 2121 Av. João Naves de Ávila Department of Dental Materials and Prosthodontics Araraquara Dental School São Paulo State University UNESP, 1680 Rua Humaitá Canadian Institutes of Health Research: # 106657 FAPESP: # 2015/06016-1 Canadian Institutes of Health Research: # 400347 FAPESP: #2016/03847-2 FAPESP: #2018/13904-9

Objectives Investigate the effects of a Bis-phenyl-glycidyl-dimethacrylate (BisGMA) biodegradation product, bishydroxypropoxyphenyl-propane (BisHPPP), on gene expression and protein synthesis of cariogenic bacteria. Methods Quantitative real-time polymerase chain reaction was used to investigate the effects of BisHPPP on the expression of specific virulence-associated genes, i.e. gtfB , gtfC , gbpB , comC , comD , comE and atpH in Streptococcus mutans UA159. Possible mechanisms for bacterial response to BisHPPP were explored using gene knock-out and associated complemented strains of the signal peptide encoding gene, comC . The effects of BisHPPP on global gene and protein expression was analyzed using microarray and quantitative proteomics. The role of BisHPPP in glucosyltransferase (GTF) enzyme activity of S. mutans biofilms was also measured. Results BisHPPP (0.01, 0.1 mM) up-regulated gtfB/C , gbpB , comCDE , and atpH most pronounced in biofilms at cariogenic pH (5.5). The effects of BisHPPP on the constructed knock-out and complemented strains of comC from quorum-sensing system, implicated this signaling pathway in up-regulation of the virulence-associated genes. Microarray and proteomics identified BisHPPP-regulated genes and proteins involved in biofilm formation, carbohydrate transport, acid tolerance and stress-response. GTF activity was higher in BisHPPP-exposed biofilms when compared to no-BisHPPP conditions. Significance These findings provide insight into the genetic and physiological pathways and mechanisms that help explain S. mutans adaptation to restorative conditions that are conducive to increased secondary caries around resin composite restorations and may provide guidance to clinicians’ decision on the selection of dental materials when considering the long term oral health of patients and the interactions of composite resins with oral bacteria.

Objectives For the first time, this study characterized the proteome of the acquired pellicle formed on human dentine. The changes in this proteome after exposure to lactic or citric acid were also evaluated. Methods Volunteers ( n = 9) wore a mandibular device containing 6 specimens of human root dentine. After the device remained in the volunteers’ oral cavities for 10 min or 2 h to allow the formation of the acquired pellicle in situ , the specimens were immersed in citric acid (1%, pH 2.5) or lactic acid (0.1 M, pH 4.8) or deionized water for 20 s. In sequence, the pellicle was collected with an electrode filter paper soaked in 3% citric acid. This procedure was repeated for two additional days following a crossover protocol. After harvest, proteins were subjected to reverse phase liquid chromatography coupled to mass spectrometry (nLC–ESI-MS/MS). MS/MS data were processed and submitted to Proteome Discoverer software. Searches were done using SWISS-PROT and TrEMBL databases for human proteins. Results In total, 223 distinct proteins were identified in the dentine acquired pellicle in each of the different conditions. Exposure to citric acid dramatically reduced the number of identified proteins. This did not occur for lactic acid. Acid-resistant proteins, such as mucins, were identified after pellicle was exposed to lactic or citric acid. Conclusions These proteins could be related to protective effect of tooth homeostasis. Moreover, in the future, they could be candidates to the development of a supplemental therapy for the prevention and treatment of dental caries and dental erosion. Clinical significance This study indicates some acid-resistant proteins that could be used in dental products to prevent dental caries and erosion.

Aim To develop a systematic review based on the relation between salivary proteins and dental caries by comparing subjects with and without caries experience and to evaluate whether salivary proteins can be considered biomarkers for dental caries or not. Methods An electronic search was performed in the PubMed Medline, Ovid Medline, ISI Web of Science, Medline, Cochrane Library, Lilacs, Scielo, BBO, Paho and Wholis databases applying the following MeSH terms: “dental caries” OR “tooth demineralization” OR “dental caries susceptibility” OR “dental enamel solubility” AND “salivary proteins and peptides” OR “saliva” AND “proteins”. To be eligible for the systematic review, the observational controlled studies had to have groups with and without caries experience. Studies with high risk of bias were excluded. Results From a total of 188 identified studies, only seven were included in this systematic review. Four studies were classified as “low risk of bias” and three as “moderate risk of bias”. Three studies reported a relation between salivary proteins and dental caries. Conclusion There was not sufficient evidence to establish salivary proteins as a biomarker for this disease although three of the seven studies showed a relation between salivary proteins and dental caries in terms of protein phenotypes, total protein concentration and protein molecular weight.

Objective The aim of this study was to investigate the type and the nature of peptides present in the in vivo formed human acquired enamel pellicle. Design Pellicle material was collected from 10 volunteers and subjected to sample preparations consisting of centrifugal filtration using a 10 kDa molecular weight cut-off membrane and high-resolution gel filtration chromatography. The fractions containing peptides Results 78 natural pellicle peptides with molecular weights ranging from 766.9 Da to 3981.4 Da were identified originating from 29 different proteins. Conclusions The number of peptides present in acquired enamel pellicle appears to be large and this is likely to enhance the functional spectrum of this protein film. The presence of small peptides in pellicle may be functionally important since structure/function studies of many salivary proteins have shown that specific domains within these native proteins retain or even exhibit enhanced biological activities. The data present the basis for determining the precise function of these pellicle peptides and for gaining insights into the role pellicle plays in the oral cavity.

Summary Objective Human saliva contains a family of low molecular weight histidine-rich proteins, named histatins, characterised by bactericidal and fungicidal activities in vitro against several microbial pathogens, such as Streptococcus mutans and Candida albicans. They represent a major component of an innate host non-immune defense system. In an earlier study we described the distribution of histatins in the glandular parenchyma of human major salivary glands, confirming that all human major salivary glands are involved in the secretion of histatins into saliva. In the present study we determined the expression and localisation of histatins in human posterior deep lingual glands (von Ebner's glands) by means of immunoelectron microscopy. Design Thin sections of normal human salivary glands, embedded in Epon resin, were incubated with rabbit polyclonal antibodies specific for human histatins and successively with a gold conjugated goat anti-rabbit IgG used as secondary antibody. Sections incubated with medium devoid of primary antibody or containing non-immune serum were used as controls. Results The serous secreting cells represented the main source of histatins in the glandular parenchyma of von Ebner's glands. At the electron microscopic level, labeling was associated with rough endoplasmic reticulum, Golgi complex and secretory granules that represented the main cytoplasmic site of histatin localisation. However, variability in the intensity of labeling was observed among adjacent cells. Conclusions The present results show for the first time that human von Ebner's glands produce and represent a significant source of histatins, supporting the hypothesis of their important role in preventing microbial assaults on the tissues in the posterior region of the tongue and in the circumvallate papillae.

Study design In this study sodium, potassium, calcium, phosphorus, zinc, and magnesium ion concentration was analyzed in stimulated whole saliva in 22 children with Down syndrome aged 6 to 10 years. These children were compared with 21 healthy children of the same age. Stimulated saliva was collected by chewing a piece of parafilm for 10 minutes. The pH was measured with a portable pH meter after collection. Electrolyte concentrations were determined by inductively coupled argon plasma with atomic emission spectrometry. Results No statistically significant differences were observed in phosphorus, zinc, magnesium, and calcium concentration between the children with Down syndrome and the control children. The sodium concentration showed about 66.8% higher value in the Down syndrome than in the control group. On the other hand the flow rate and potassium concentration were lower in the Down syndrome than in the control group. Conclusion Our results suggest that there is alteration in the metabolism of the duct and/or acinar cells of salivary glands of Down syndrome children.