Metabolomics for dental caries diagnosis: Past, present, and future.

Dental caries, a prevalent global infectious condition affecting over 95% of adults, remains elusive in its precise etiology. Addressing the complex dynamics of caries demands a thorough exploration of taxonomic, potential, active, and encoded functions within the oral ecosystem. Metabolomic profiling emerges as a crucial tool, offering immediate insights into microecosystem physiology and linking directly to the phenotype. Identified metabolites, indicative of caries status, play a pivotal role in unraveling the metabolic processes underlying the disease. Despite challenges in metabolite variability, the use of metabolomics, particularly via mass spectrometry and nuclear magnetic resonance spectroscopy, holds promise in caries research. This review comprehensively examines metabolomics in caries prevention, diagnosis, and treatment, highlighting distinct metabolite expression patterns and their associations with disease-related bacterial communities. Pioneering in approach, it integrates singular and combinatory metabolomics methodologies, diverse biofluids, and study designs, critically evaluating prior limitations while offering expert insights for future investigations. By synthesizing existing knowledge, this review significantly advances our comprehension of caries, providing a foundation for improved prevention and treatment strategies.

Proteomic Analysis of Human Saliva via Solid-Phase Microextraction Coupled with Liquid Chromatography-Mass Spectrometry.

Proteomics of human saliva samples was achieved for the first time via biocompatible solid-phase microextraction (bio-SPME) devices. Upon introduction of a porogen to a conventional C18 coating, porous C18/polyacrylonitrile (PAN) SPME blades were able to extract peptides up to 3.0 kDa and more peptides than commercial SPME blades. Following Trypsin digestion, salivary proteomic analysis was achieved via SPME-LC-MS/MS. Seven endogenous proteins were consistently identified in all saliva samples via bio-SPME. Taking advantage of this strategy, untargeted peptidomics was applied for the comparison of saliva samples between healthy and SARS-CoV-2 positive individuals. The results showed clear peptidomic differences between the viral and healthy saliva samples. This proof-of-concept study demonstrates the potential of bio-SPME-LC-MS/MS for peptidomics and proteomics in biomedical applications.

Progression from healthy periodontium to gingivitis and periodontitis: Insights from bioinformatics-driven proteomics - A systematic review with meta-analysis.

AIM: The current study aimed to: (1) systematically review the published literature regarding the proteomics analyses of saliva and gingival crevicular fluid (GCF) in healthy humans and gingivitis and/or periodontitis patients; and (2) to identify the differentially expressed proteins (DEPs) based on the systematic review, and comprehensively conduct meta-analyses and bioinformatics analyses. METHODS: An online search of Web of Science, Scopus, and PubMed was performed without any restriction on the year and language of publication. After the identification of the DEPs reported by the included human primary studies, gene ontology (GO), the Kyoto encyclopedia of genes and genomes pathway (KEGG), protein-protein interaction (PPI), and meta-analyses were conducted. The risk of bias among the included studies was evaluated using the modified Newcastle-Ottawa quality assessment scale. RESULTS: The review identified significant differences in protein expression between healthy individuals and those with gingivitis and periodontitis. In GCF, 247 proteins were upregulated and 128 downregulated in periodontal diseases. Saliva analysis revealed 79 upregulated and 70 downregulated proteins. There were distinct protein profiles between gingivitis and periodontitis, with 159 and 31 unique upregulated proteins in GCF, respectively. Meta-analyses confirmed significant upregulation of various proteins in periodontitis, including ALB and MMP9, while CSTB and GSTP1 were downregulated. AMY1A and SERPINA1 were upregulated in periodontitis saliva. HBD was upregulated in gingivitis GCF, while DEFA3 was downregulated. PPI analysis revealed complex networks of interactions among DEPs. GO and KEGG pathway analyses provided insights into biological processes and pathways associated with periodontal diseases. CONCLUSION: The ongoing MS-based proteomics studies emphasize the need for a highly sensitive and specific diagnostic tool for periodontal diseases. Clinician acceptance of the eventual diagnostic method relies on its ability to provide superior or complementary information to current clinical assessment procedures. Future research should prioritize the multiplex measurement of multiple biomarkers simultaneously to enhance diagnostic accuracy and large study cohorts are necessary to ensure the validity and reliability of research findings.

Mass spectrometry-based proteomics profiling of dogs with and without oral diseases: a systematic review.

BACKGROUND: Understanding the distinct proteomics profiles in dogs' oral biofluids enhances diagnostic and therapeutic insights for canine oral diseases, fostering cross-species translational research in dentistry and medicine. This study aimed to conduct a systematic review to investigate the similarities and differences between the oral biofluids' proteomics profile of dogs with and without oral diseases. METHODS: PubMed, Web of Science, and Scopus were searched with no restrictions on publication language or year to address the following focused question: "What is the proteome signature of healthy versus diseased (oral) dogs' biofluids?" Gene Ontology enrichment and the Kyoto Encyclopedia of Genes and Genomes pathway analyses of the most abundant proteins were performed. Moreover, protein-protein interaction analysis was conducted. The risk of bias (RoB) among the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data. RESULTS: In healthy dogs, the proteomic analysis identified 5,451 proteins, with 137 being the most abundant, predominantly associated with 'innate immune response'. Dogs with oral diseases displayed 6,470 proteins, with distinct associations: 'defense response to bacterium' (periodontal diseases), 'negative regulation of transcription' (dental calculus), and 'positive regulation of transcription' (oral tumors). Clustering revealed significant protein clusters in each case, emphasizing the diverse molecular profiles in health and oral diseases. Only six studies were provided to the JBI tool, as they encompassed case-control evaluations that compared healthy dogs to dogs with oral disease(s). All included studies were found to have low RoB (high quality). CONCLUSION: Significant differences in the proteomics profiles of oral biofluids between dogs with and without oral diseases were found. The synergy of animal proteomics and bioinformatics offers a promising avenue for cross-species research, despite persistent challenges in result validation.

Mass spectrometry-based proteomic approaches for salivary protein biomarkers discovery and dental caries diagnosis: A critical review.

Dental caries is a multifactorial chronic disease resulting from the intricate interplay among acid-generating bacteria, fermentable carbohydrates, and several host factors such as saliva. Saliva comprises several proteins which could be utilized as biomarkers for caries prevention, diagnosis, and prognosis. Mass spectrometry-based salivary proteomics approaches, owing to their sensitivity, provide the opportunity to investigate and unveil crucial cariogenic pathogen activity and host indicators and may demonstrate clinically relevant biomarkers to improve caries diagnosis and management. The present review outlines the published literature of human clinical proteomics investigations on caries and extensively elucidates frequently reported salivary proteins as biomarkers. This review also discusses important aspects while designing an experimental proteomics workflow. The protein-protein interactions and the clinical relevance of salivary proteins as biomarkers for caries, together with uninvestigated domains of the discipline are also discussed critically.

Identification of SARS-CoV-2 biomarkers in saliva by transcriptomic and proteomics analysis.

The detection of SARS-CoV-2 biomarkers by real time PCR (rRT-PCR) has shown that the sensitivity of the test is negatively affected by low viral loads and the severity of the disease. This limitation can be overcome by the use of more sensitive approaches such as mass spectrometry (MS), which has not been explored for the detection of SARS-CoV-2 proteins in saliva. Thus, this study aimed at assessing the translational applicability of mass spectrometry-based proteomics approaches to identify viral proteins in saliva from people diagnosed with COVID-19 within fourteen days after the initial diagnosis, and to compare its performance with rRT-PCR. After ethics approval, saliva samples were self-collected by 42 COVID-19 positive and 16 healthy individuals. Samples from people positive for COVID-19 were collected on average on the sixth day (± 4 days) after initial diagnosis. Viable viral particles in saliva were heat-inactivated followed by the extraction of total proteins and viral RNA. Proteins were digested and then subjected to tandem MS analysis (LC-QTOF-MS/MS) using a data-dependent MS/MS acquisition qualitative shotgun proteomics approach. The acquired spectra were queried against a combined SARS-CoV-2 and human database. The qualitative detection of SARS-CoV-2 specific RNA was done by rRT-PCR. SARS-CoV-2 proteins were identified in all COVID-19 samples (100%), while viral RNA was detected in only 24 out of 42 COVID-19 samples (57.1%). Seven out of 18 SARS-CoV-2 proteins were identified in saliva from COVID-19 positive individuals, from which the most frequent were replicase polyproteins 1ab (100%) and 1a (91.3%), and nucleocapsid (45.2%). Neither viral proteins nor RNA were detected in healthy individuals. Our mass spectrometry approach appears to be more sensitive than rRT-PCR for the detection of SARS-CoV-2 biomarkers in saliva collected from COVID-19 positive individuals up to 14 days after the initial diagnostic test. Based on the novel data presented here, our MS technology can be used as an effective diagnostic test of COVID-19 for initial diagnosis or follow-up of symptomatic cases, especially in patients with reduced viral load.

Validity and reliability of the COVID-19 Anxiety Syndrome Scale in Canadian dentists.

BACKGROUND: The COVID-19 pandemic has resulted in a high level of mental health problems for the population worldwide including healthcare workers. Several studies have assessed these using measurements for anxiety for general populations. The COVID-19 Anxiety Syndrome Scale (C-19ASS) is a self-report measure developed to assess maladaptive forms of coping with COVID-19 (avoidance, threat monitoring and worry) among a general adult population in the United States. We used it in a prospective cohort study of COVID-19 incidence rates in practising Canadian dentists. We therefore need to ensure that it is valid for dentists in French and English languages. This study aimed to evaluate the validity of the C-19ASS in that population. METHODS: Cross-sectional data from the January 2021 monthly follow-up in our prospective cohort study were used. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed. RESULTS: The results of EFA revealed a 2-factor structure solution that explained 47% of the total variance. The CFA showed a good model fit on the data in both English and French languages. The Cronbach's alpha indicated acceptable levels of reliability. Furthermore, the C-19ASS showed excellent divergent validity from the Generalized Anxiety Disorder-7 (GAD-7) scale. CONCLUSIONS: The C-19ASS is valid and reliable instrument to measure COVID-19-related anxiety in English and French among Canadian dentists. PRACTICAL IMPLICATIONS: This validated measure will contribute to understanding of the mental health impact of the pandemic on dentists in Canada and enable the dental regulatory authorities and organizations to intervene to help dentists.

Salivary Proteins as Dental Caries Biomarkers: A Systematic Review.

Salivary proteins play an important role in repairing mechanisms of damaged tissues and the maintenance of oral health. However, there is a dearth of information in the literature regarding the concentrations of salivary proteins in caries-free (CF) and caries-active (CA) subjects. Hence, this systematic review was conducted to update our previous systematic review published in 2013 that aimed to assess the association between caries and salivary proteins by comparing CF and CA individuals. Thereby, evaluating the possibility of whether salivary proteins can be regarded as biomarkers for caries. An extensive search of studies was conducted using PubMed, EMBASE, Clarivate Analytics' Web of Science, and Elsevier's Scopus between July 2012 and January 2022, without any language restriction. Manual searching in Google Scholar and evaluation of bibliographies of the included studies were also undertaken. The Newcastle-Ottawa Scale was used to assess the risk of bias (RoB) within the included studies. Of 22 included studies, 1,551 human subjects (range: 30-213 participants) were recruited, of which 848 individuals (54.7%) were CA and 703 (45.3%) were CF. Regarding the utilization of DMFT as the caries index, high variability was observed across different articles. A statistically significant increase in the salivary levels of alpha-amylase, acidic proline-rich protein-1, histatin-5, lactoperoxidase, and mucin-1 was found in CA patients, while the salivary levels of carbonic anhydrase 6, proteinase-3, and statherin were observed to be significantly increased in CF subjects. Conflicting results were found regarding the salivary levels of immunoglobulin A and total proteins among CA and CF subjects. The included studies were categorized as low RoB (n = 15), medium RoB (n = 4), and high RoB (n = 3). Due to significant heterogeneity among the included studies, no meta-analysis could be performed. In conclusion, the salivary levels of protein(s) might be a useful biomarker for caries diagnosis, especially alpha-amylase, acidic proline-rich protein-1, histatin-5, lactoperoxidase, mucin-1, carbonic anhydrase 6, proteinase-3, and statherin. However, their diagnostic value must be verified by large-scale prospective studies.

Evaluating protein binding specificity of titanium surfaces through mass spectrometry-based proteomics.

OBJECTIVES: To evaluate whether surface characteristics of different titanium modifications may influence the composition of the salivary pellicle on each surface by analyzing the salivary proteome through mass spectrometry-based proteomics. MATERIALS AND METHODS: Titanium discs with three surfaces modifications (PT (machined titanium), SLA (sandblasted/large-grit/acid-etched), and SLActive (modified SLA)) were characterized (topography, chemistry, and energy) prior to being exposed to saliva for 2 h to form a protein pellicle. The resultant protein layer was retrieved and analyzed through mass spectrometry (nLC-ESI-MS/MS) to examine the surface specificity for protein binding, while the proteome profile of each surface was classified. RESULTS: The proteome analysis showed that the salivary pellicle composition was more complex on rough surfaces (SLA and SLActive). Although variability in protein composition was observed between surfaces, most proteins were detected on more than one surface, indicating a limited surface specificity for protein binding. Additionally, the salivary pellicle formed on the SLActive presented a larger number of proteins associated with immune response, biological adhesion, and biomineralization. CONCLUSIONS: Although topography, chemistry, and energy differed between the surfaces, they were not determinant to produce a salivary pellicle with high surface specificity. Also, we showed that several salivary proteins adsorbed on Ti surfaces are involved in biological functions important to the biointegration. CLINICAL RELEVANCE: This study sheds light on the necessity for the development of bioactive surfaces that favors the formation of a specific protein layer that can enhance tissue response to assist the biointegration of dental implants.

Proteomic profile of saliva collected directly from ducts: a systematic review.

OBJECTIVE: To present a systematic review that provides updated information about proteins found in salivary fluid extracted strictly from ducts. METHODS: The systematic review probing strategy was based on electronic databases word search (PubMed, EMBASE, LILACS, Web of Science, and Scopus). Risk of bias was assessed based on Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. RESULTS: After 2 rounds of scrutiny, 12 articles were included, totaling 231 individuals (125 were healthy, 41 were elder individuals with radicular caries, 56 had primary Sjögren's syndrome, and 9 were patients who had received radiotherapy for head and neck cancer). The selected studies had no similarities among proteins found, demonstrating the need of standard reference in experimental methodology to obtain a thorough coverage of proteins. CONCLUSION: Further studies are required to better determine the relative amount of proteins described in this study. It is essential to increase the number of samples, to perform similar collection techniques, to include other analyses methods such as mass spectrometry, and to perform the validation of some proteins using immunoassay techniques such as Elisa and Western blot. CLINICAL RELEVANCE: Proteomic profile of saliva collected from ducts is essential to better understand the disease process, enabling the identification of biomarkers for specific clinical situations.

Investigating the association between stress, saliva and dental caries: a scoping review.

BACKGROUND: This scoping review addressed the question 'what do we know about stress-related changes in saliva and dental caries in general population?' METHODS: The review was conducted using electronic searches via Embase, MEDLINE, PsycINFO, CINAHL and WoS. All published human studies with both observational and experimental designs were included. Two reviewers independently reviewed eligible articles and extracted the data. The studies' quality was assessed using the Effective Public Health Practice Project Quality Assessment Tool. RESULTS: Our search identified 232 reports, of which six were included in this review. All six studies were conducted in children and used salivary cortisol as stress marker. The studies varied by design, types of stressors, children's caries experience, methods of saliva collection. Four studies reported a positive association between saliva cortisol levels and caries (p < 0.05) while the other two reported no association (p > 0.05). The quality of the included studies was weak to moderate. CONCLUSIONS: There is lack of evidence about an association between stress-related changes in saliva and caries. Well-designed longitudinal studies with rigorous measurement technics for stress, saliva and dental caries are necessary. This will help to generate new insights into the multifactorial etiology of caries and provide evidence for a rational method for its control.

Effectiveness of chemical disinfection on biofilms of relined dentures: A randomized clinical trial.

PURPOSE: To evaluate the effect of disinfection with sodium perborate or chlorhexidine (when combined with brushing) on the removal of biofilm in relined dentures. METHODS: Swabs were collected 48 hours after the relining procedure and at the follow-up time intervals of 7, 15, 30, 90, and 180 days. The dentures' surface roughness was measured at the same times. 45 subjects were randomly divided into three groups of 15 subjects each. The control group brushed with coconut soap and a soft toothbrush. The sodium perborate group followed the same procedure and also disinfected with sodium perborate solution for 5 minutes per day. The chlorhexidine group followed the control group procedure and disinfected with 2% chlorhexidine digluconate solution for 5 minutes per day. The number of colony forming units and the surface roughness were evaluated statistically by 2-way repeated-measure ANOVA (α = 0.05). RESULTS: The control group dentures exhibited similar levels of microbial cells throughout the experiment. However, after 15 days, no microbial growth was observed on the dentures for which either disinfection agent was used. There were no statistically significant differences in superficial roughness between the groups (P = 0.298). The disinfection agents used, combined with brushing, were able to remove the relined dentures' biofilm after 15 days of disinfection. Roughness was not a predominant factor in CFU reduction.

Acute vibration induces transient expression of anabolic genes in the murine intervertebral disc.

OBJECTIVE: Low-amplitude whole-body vibration has been adopted for the treatment of back pain and spinal disorders. However, there is limited knowledge of the impact of vibration on the intervertebral disc (IVD). This study was undertaken to examine the effects of acute vibration on anabolic and catabolic pathways in the IVD and to characterize the dependence of these changes on time and frequency. METHODS: Custom-designed platforms were developed to apply acute vibration to ex vivo and in vivo mouse models. Spinal segments (ex vivo) or mice (in vivo) were subjected to vibration (for 30 minutes at 15-90 Hz with peak acceleration at 0.3g), and IVDs were examined at specific time points after vibration. Gene expression was quantified using real-time polymerase chain reaction, and protein levels were examined by quantitative mass spectrometry and immunofluorescence. RESULTS: In the ex vivo model, acute vibration at 15 Hz induced expression of anabolic genes (aggrecan, biglycan, decorin, type I collagen, and Sox9) and suppressed expression of Mmp13, with the most pronounced changes detected 6 hours following vibration. These beneficial effects were frequency dependent and were no longer evident between 45 and 90 Hz. In vivo, the effects on anabolic gene expression were even more robust and were accompanied by decreased expression of Adamts4, Adamts5, and Mmp3. Moreover, significant increases in the protein levels of aggrecan, biglycan, decorin, and type I collagen were detected in vivo. CONCLUSION: These findings demonstrate dramatic anabolic effects of acute vibration on IVD tissue, responses that are dependent on frequency. The similarity of the in vivo and ex vivo responses indicates that at least some effects of vibration are tissue autonomous.

Salivary protein homology between humans and dogs: Mass spectrometry-based proteomics analysis.

OBJECTIVE: This benchmark study aimed to investigate sex-related differences based on the identification and characterization of the salivary proteome of healthy male and female dogs using mass spectrometry (MS) technique and a homology-driven approach to analyze salivary proteins in both human and dog species utilizing protein sequence alignment technique. METHODS: Unstimulated whole saliva was collected from 10 healthy Beagles. After processing the samples and determining the total protein content, in-solution protein digestion was performed involving denaturation, reduction of disulfide bonds, alkylation, and removal of interfering compounds. Samples were analyzed using LC-ESI-MS/MS. RESULTS: LC-ESI-MS/MS analysis identified 327 and 341 unique proteins in male and female dog saliva, respectively, of which 318 (97.25 %) in male dogs and 326 (95.60 %) in female dogs were characterized. Abundant shared proteins included albumin, BPI fold-containing family A member 2, and VWFD domain-containing protein. A notable uncharacterized protein, VWFD domain-containing protein, was among the most abundant in both sexes. Comparative analysis of 69 abundant shared proteins indicated an upregulation of CES5A, EFHD, GC, IGHM, LOC100653049, KRT10, LCP1, PGD, TPI1 in male dogs, while LOC100855593 was upregulated in female dogs. In total, 84 % (n = 229/274) and 86 % (n = 235/275) salivary proteins identified in male and female dogs, respectively, were homologous to human proteins, with an overall homology of 86 % (n = 364/423), including 15 with 100 % homology. CONCLUSION: The study revealed clear differences in the salivary proteomics profile of healthy male and female dogs. However, most of the salivary proteins in both male and female dogs showed homology with human salivary proteins. CLINICAL RELEVANCE: The identification of unique salivary proteome profiles in male and female dogs, coupled with substantial homology to human proteins, provides promising biomarkers for health assessment, highlighting its clinical significance for diagnostics and therapeutic exploration not only in veterinary and human dentistry, but across mammalian species.

Antibiofilm Activity and Biocompatibility of Temporin-SHa: A Promising Antimicrobial Peptide for Control of Fluconazole-Resistant Candida albicans.

The aim of the study was to investigate the effect of antimicrobial peptides (AMPs) Hylin-a1, KR-12-a5, and Temporin-SHa in Candida albicans as well as the biocompatibility of keratinocytes spontaneously immortalized (NOK-si) and human gingival fibroblasts (FGH) cells. Initially, the susceptible (CaS-ATCC 90028) and fluconazole-resistant (CaR-ATCC 96901) C. albicans strains were grown to evaluate the effect of each AMP in planktonic culture, biofilm, and biocompatibility on oral cells. Among the AMPs evaluated, temporin-SHa showed the most promising results. After 24 h of Temporin-SHa exposure, the survival curve results showed that CaS and CaR suspensions reduced 72% and 70% of cell viability compared to the control group. The minimum inhibitory/fungicide concentrations (MIC and MFC) showed that Temporin-SHa was able to reduce ≥50% at ≥256 µg/mL for both strains. The inhibition of biofilm formation, efficacy against biofilm formation, and total biomass assays were performed until 48 h of biofilm maturation, and Temporin-SHa was able to reduce ≥50% of CaS and CaR growth. Furthermore, Temporin-SHa (512 µg/mL) was classified as non-cytotoxic and slightly cytotoxic for NOK-si and FGH, respectively. Temporin-SHa demonstrated an anti-biofilm effect against CaS and CaR and was biocompatible with NOK-si and FGH oral cells in monolayer.

Proteome and peptidome of human acquired enamel pellicle on deciduous teeth.

Understanding the composition and structure of the acquired enamel pellicle (AEP) has been a major goal in oral biology. Our lab has conducted studies on the composition of AEP formed on permanent enamel. The exhaustive exploration has provided a comprehensive identification of more than 100 proteins from AEP formed on permanent enamel. The AEP formed on deciduous enamel has not been subjected to the same biochemical characterization scrutiny as that of permanent enamel, despite the fact that deciduous enamel is structurally different from permanent enamel. We hypothesized that the AEP proteome and peptidome formed on deciduous enamel may also be composed of unique proteins, some of which may not be common with AEP of permanent enamel explored previously. Pellicle material was collected from 10 children (aged 18-54 months) and subjected to mass spectrometry analysis. A total of 76 pellicle proteins were identified from the deciduous pellicle proteome. In addition, 38 natural occurring AEP peptides were identified from 10 proteins, suggesting that primary AEP proteome/peptidome presents a unique proteome composition. This is the first study to provide a comprehensive investigation of in vivo AEP formed on deciduous enamel.

Brewing better connections: Coffee with the dean to enhance admin-student communication.

Effective communication is pivotal in nurturing a supportive learning atmosphere. At the University of Saskatchewan's College of Dentistry, traditional methods like emails and meetings seemed inadequate in engaging all students. Concerns stemmed from power dynamics and limited dialogue avenues. To bridge this gap, an innovative solution emerged. Introducing "Coffee with the Dean": A bi-weekly event fostering informal discussions between students and the dean. Set in a relaxed ambiance, students openly covered diverse topics. The project aimed to foster transparent communication and bolster a sense of unity. Implemented over six months, the initiative saw significant outcomes. Assessment involved an anonymous survey to DMD students, garnering a 34% response rate. Impressively, 89% acknowledged enhanced communication, with 53% and 23% expressing high and moderate satisfaction in asking questions and providing feedback. Moreover, 67% displayed a likelihood to attend future sessions. A notable 89% appreciated the project's community-building impact. Although challenges emerged, including scheduling and participation constraints, the project achieved its goal. The casual setup facilitated student expression and prompted insightful exchanges. The experience emphasizes the importance of secure dialogue spaces and consistent communication channels. "Coffee with the Dean" stands as a potent tool for heightened student-administration interaction. Its role in elevating communication aligns with the quest for educational excellence, ensuring holistic student growth.

Personal protective equipment during COVID-19: A natural history of dental and dental hygiene regulatory guidance in Canada.

BACKGROUND: Due to the evolving nature of COVID-19, there is evidence that COVID-19-specific infection prevention and control guideline (IPCG) documents formulated for oral health care settings are also changing rapidly. To better inform future policies, a comprehensive review of all IPCG documents across different phases of restrictions for oral health care practitioners is required. TYPES OF STUDIES REVIEWED: A search was performed for documents shared from March 2020 through January 2022 on websites of oral health regulatory authorities in Canada's 10 provinces and 3 territories. The authors performed a narrative review of the identified IPCG documents for dentists (n = 78) and dental hygienists (n = 57). RESULTS: Overall findings from more than 100 IPCG documents distributed during a period of 23 months revealed that the frequency of these updates differed among jurisdictions and between the 2 oral health care practitioners (ie, dentists and dental hygienists) within the same jurisdiction. The most notable observation was the different face-covering recommendations for dentists and dental hygienists within the same jurisdiction during the same timeframe. A common document was sometimes observed for dentists and dental hygienists, however, most jurisdictions had separate IPCG documents. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The different approaches could have been justified on the basis of prevalence of COVID-19 and availability of personal protective equipment; however, there was a risk of creating confusion about IPCG best practices. The findings of this review will support decision makers when planning future development and dissemination of regulations for all oral health care practitioners.

Identification and characterization of histatin 1 salivary complexes by using mass spectrometry.

With recent progress in the analysis of the salivary proteome, the number of salivary proteins identified has increased dramatically. However, the physiological functions of many of the newly discovered proteins remain unclear. Closely related to the study of a protein's function is the identification of its interaction partners. We investigated interactions among and functions of histatin 1 and the other proteins that are present in saliva by using high-throughput mass spectrometric techniques. This led to the identification of 43 proteins able to interact with histatin 1. In addition, we found that these protein-protein interactions protect complex partners from proteolysis and modulate their antifungal activity. Our data contribute significantly to characterization of the salivary interactome and to understanding the biology of salivary protein complexes.