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Journal of Dental Research Dec 2013Many infectious diseases in humans are caused or exacerbated by biofilms. Dental caries is a prime example of a biofilm-dependent disease, resulting from interactions of... (Review)
Review
Many infectious diseases in humans are caused or exacerbated by biofilms. Dental caries is a prime example of a biofilm-dependent disease, resulting from interactions of microorganisms, host factors, and diet (sugars), which modulate the dynamic formation of biofilms on tooth surfaces. All biofilms have a microbial-derived extracellular matrix as an essential constituent. The exopolysaccharides formed through interactions between sucrose- (and starch-) and Streptococcus mutans-derived exoenzymes present in the pellicle and on microbial surfaces (including non-mutans) provide binding sites for cariogenic and other organisms. The polymers formed in situ enmesh the microorganisms while forming a matrix facilitating the assembly of three-dimensional (3D) multicellular structures that encompass a series of microenvironments and are firmly attached to teeth. The metabolic activity of microbes embedded in this exopolysaccharide-rich and diffusion-limiting matrix leads to acidification of the milieu and, eventually, acid-dissolution of enamel. Here, we discuss recent advances concerning spatio-temporal development of the exopolysaccharide matrix and its essential role in the pathogenesis of dental caries. We focus on how the matrix serves as a 3D scaffold for biofilm assembly while creating spatial heterogeneities and low-pH microenvironments/niches. Further understanding on how the matrix modulates microbial activity and virulence expression could lead to new approaches to control cariogenic biofilms.
Topics: Biofilms; Cellular Microenvironment; Dental Caries; Dental Plaque; Humans; Hydrogen-Ion Concentration; Polysaccharides, Bacterial; Streptococcus mutans; Virulence
PubMed: 24045647
DOI: 10.1177/0022034513504218 -
Journal of Dental Research Jun 2020The oral microbiome is one of the most stable ecosystems in the body and yet the reasons for this are still unclear. As well as being stable, it is also highly diverse... (Review)
Review
The oral microbiome is one of the most stable ecosystems in the body and yet the reasons for this are still unclear. As well as being stable, it is also highly diverse which can be ascribed to the variety of niches available in the mouth. Previous studies have focused on the microflora in disease-either caries or periodontitis-and only recently have they considered factors that maintain the normal microflora. This has led to the perception that the microflora proliferate in nutrient-rich periods during oral processing of foods and drinks and starves in between times. In this review, evidence is presented which shows that the normal flora are maintained on a diet of salivary factors including urea, lactate, and salivary protein degradation. These factors are actively secreted by salivary glands which suggests these factors are important in maintaining normal commensals in the mouth. In addition, the immobilization of SIgA in the mucosal pellicle indicates a mechanism to retain certain bacteria that does not rely on the bacterial-centric mechanisms such as adhesins. By examining the salivary metabolome, it is clear that protein degradation is a key nutrient and the availability of free amino acids increases resistance to environmental stresses.
Topics: Dental Pellicle; Immunoglobulin A, Secretory; Microbiota; Mouth; Saliva; Salivary Proteins and Peptides
PubMed: 32283990
DOI: 10.1177/0022034520915486 -
Microbiome Mar 2023Dental erosion is a disease of the oral cavity where acids cause a loss of tooth enamel and is defined as having no bacterial involvement. The tooth surface is protected...
BACKGROUND
Dental erosion is a disease of the oral cavity where acids cause a loss of tooth enamel and is defined as having no bacterial involvement. The tooth surface is protected from acid attack by salivary proteins that make up the acquired enamel pellicle (AEP). Bacteria have been shown to readily degrade salivary proteins, and some of which are present in the AEP. This study aimed to explore the role of bacteria in dental erosion using a multi-omics approach by comparing saliva collected from participants with dental erosion and healthy controls.
RESULTS
Salivary proteomics was assessed by liquid-chromatography mass spectrometry (LC-MS) and demonstrated two altered AEP proteins in erosion, prolactin inducible protein (PIP), and zinc-alpha-2 glycoprotein (ZAG). Immunoblotting further suggested that degradation of PIP and ZAG is associated with erosion. Salivary microbiome analysis was performed by sequencing the bacterial 16S rRNA gene (V1-V2 region, Illumina) and showed that participants with dental erosion had a significantly (p < 0.05) less diverse microbiome than healthy controls (observed and Shannon diversity). Sequencing of bacterial mRNA for gene expression (Illumina sequencing) demonstrated that genes over-expressed in saliva from erosion participants included H + proton transporter genes, and three protease genes (msrAB, vanY, and ppdC). Salivary metabolomics was assessed using nuclear magnetic resonance spectrometry (NMR). Metabolite concentrations correlated with gene expression, demonstrating that the dental erosion group had strong correlations between metabolites associated with protein degradation and amino acid fermentation.
CONCLUSIONS
We conclude that microbial proteolysis of salivary proteins found in the protective acquired enamel pellicle strongly correlates with dental erosion, and we propose four novel microbial genes implicated in this process. Video Abstract.
Topics: Humans; Tooth Erosion; Proteolysis; Dysbiosis; RNA, Ribosomal, 16S; Saliva; Salivary Proteins and Peptides; Peptide Hydrolases
PubMed: 37004076
DOI: 10.1186/s40168-023-01514-0 -
Scanning 2020Hydroxyapatite nanoparticles (nano-HAP) are receiving considerable attention for dental applications, and their adhesion to enamel is well established. However, there...
Hydroxyapatite nanoparticles (nano-HAP) are receiving considerable attention for dental applications, and their adhesion to enamel is well established. However, there are no reports concerning the effects of HAP on other dental materials, and most of the studies in this field are based on designs, neglecting the salivary pellicle-apatite interactions. Thus, this pilot study aims to evaluate the effects of three hydroxyapatite-based solutions and their interactions with different dental material surfaces under oral conditions. Hence, two volunteers carried intraoral splints with mounted samples from enamel and from three dental materials: titanium, ceramics, and polymethyl-methacrylate (PMMA). Three HAP watery solutions (5%) were prepared with different shapes and sizes of nano-HAP (HAP I, HAP II, HAP III). After 3 min of pellicle formation, 10 ml rinse was performed during 30 sec. Rinsing with water served as control. Samples were accessed immediately after rinsing, 30 min and 2 h after rinsing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the particles, and SEM evaluated the pellicle-HAP interactions. SEM and TEM results showed a high variation in the size range of the particles applied. A heterogeneous HAP layer was present after 2 h on enamel, titanium, ceramics, and PMMA surfaces under oral conditions. Bridge-like structures were visible between the nano-HAP and the pellicle formed on enamel, titanium, and PMMA surfaces. In conclusion, nano-HAP can adhere not only to enamel but also to artificial dental surfaces under oral conditions. The experiment showed that the acquired pellicle act as a bridge between the nano-HAP and the materials' surface.
Topics: Adult; Bacterial Adhesion; Ceramics; Dental Materials; Durapatite; Female; Humans; Male; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nanoparticles; Pilot Projects; Surface Properties; Titanium; Tooth Erosion
PubMed: 32454927
DOI: 10.1155/2020/6065739 -
Journal of Dentistry May 2021To evaluate in vivo the proteomic profile of the acquired enamel pellicle (AEP) in patients with head and neck cancer (HNC) before, during and after radiotherapy.
OBJECTIVES
To evaluate in vivo the proteomic profile of the acquired enamel pellicle (AEP) in patients with head and neck cancer (HNC) before, during and after radiotherapy.
METHODS
Nine patients, after prophylaxis, had their AEPs collected before (BRT), during (DRT; 2-5 weeks) and after (ART; 3-4 months) radiotherapy. AEP was also collected from nine healthy patients (Control). The proteins were extracted in biological triplicate and processed by label-free proteomics.
RESULTS
Statherin was increased more than 9-fold and several hemoglobin subunits were increased more than 5-fold DRT compared to BRT, while lactotransferrin, proline-rich proteins, cystatins, neutrophil defensins 1 and 3 and histatin-1 were decreased. ART, there was an increase in lactotransferrin and several isoforms of histones, while statherin and alpha-amylase proteins were decreased. MOAP-1 was exclusively found ART in comparison to BRT. When compared to Control, AEP of patients BRT showed an increase in proteins related to the perception of bitter taste, mucin-7 and alpha-amylases, while cystatin-S was decreased.
CONCLUSIONS
HNC and radiotherapy remarkably altered the proteome of the AEP. Antibacterial and acid-resistant proteins were decreased during radiotherapy.
CLINICAL SIGNIFICANCE
Our results provide important information for designing more effective dental products for these patients, in addition to contributing to a better understanding of the differential protective roles of the AEP proteins during radiotherapy. Moreover, some proteins identified in the AEP after radiotherapy may serve as prognostic markers for survival of HNC patients.
Topics: Dental Enamel Proteins; Dental Pellicle; Head and Neck Neoplasms; Humans; Proteome; Proteomics; Saliva; Salivary Proteins and Peptides
PubMed: 33757866
DOI: 10.1016/j.jdent.2021.103642 -
Caries Research 2011In vitro and in situ studies modelling the wear of dental hard tissues due to erosion and abrasion are characterised by a high variation in study designs and... (Review)
Review
In vitro and in situ studies modelling the wear of dental hard tissues due to erosion and abrasion are characterised by a high variation in study designs and experimental parameters. Based on a summary of the existing protocols, the present review aimed to describe and discuss the parameters which must be carefully considered in erosion-abrasion research, especially when it is intended to simulate clinical conditions. Experimental characteristics and parameters were retrieved from a total of 42 in vitro and 20 in situ studies. The key experimental characteristics included parameters of erosion (duration and pH) and abrasion (duration, kinds of toothbrush and toothpaste, brushing force, and time point) as well as co-factors (e.g. dental hard tissue). The majority of studies used models with alternating erosion/abrasion treatments intended to simulate clinical conditions, while other studies exaggerated clinical conditions intentionally, often using only a single erosion/abrasion treatment. Both in vitro and in situ models shared a high level of standardisation, but several studies showed a trend to severe erosion (e.g. >5 min/cycle) or extensive brushing (e.g. >100 brushing strokes/cycle) at a high frequency and repetition rate. Thus, studies often tend to produce a higher amount of wear than in the clinical situation, especially as modifying biological factors (e.g. the dilution of the erosive solution by saliva and the protective effect of the pellicle) cannot be simulated adequately. With respect to the existing models, it seems advisable to diminish duration and frequency of erosion and abrasion to more realistic clinical conditions when the everyday situation is to be simulated. Experimental parameters must be chosen with care to ensure that the problem is investigated in an appropriate mode at standardised conditions and with adequate measuring systems to allow prediction of clinical outcomes.
Topics: Animals; Dental Enamel; Dental Pellicle; Dentin; Forecasting; Humans; Hydrogen-Ion Concentration; Research Design; Saliva; Stress, Mechanical; Time Factors; Tooth Abrasion; Tooth Erosion; Toothbrushing; Toothpastes
PubMed: 21625133
DOI: 10.1159/000325946 -
Scientific Reports Jan 2020Pellicle is the initial proteinaceous layer that is formed almost instantaneously on all solid surfaces in the oral cavity. It is of essential relevance for any...
Pellicle is the initial proteinaceous layer that is formed almost instantaneously on all solid surfaces in the oral cavity. It is of essential relevance for any interactions and metabolism on the tooth surface. Up to now, there is no information on the metabolome of this structure. Accordingly, the present study aims to characterise the metabolomic profile of in-situ pellicle in children with different caries activity for the first time in comparison to saliva. Small molecules such as carbohydrates, amino acids, organic acids, and fatty acids, putatively involved in the formation of caries were quantified using mass spectrometry (MS)-based techniques, such as (stable isotope dilution analysis)-ultra-performance liquid chromatography-tandem MS and gas chromatography/electron ionisation-MS. Pellicle and corresponding saliva samples were collected from caries-active, caries-free and caries-rehabilitated 4- to 6-year-old children. The most abundant analytes in pellicle were acetic acid (1.2-10.5 nmol/cm), propionic acid (0.1-8.5 nmol/cm), glycine (0.7-3.5 nmol/cm), serine (0.08-2.3 nmol/cm), galactose (galactose + mannose; 0.035-0.078 nmol/cm), lactose (0.002-0.086 nmol/cm), glucose (0.018-0.953 nmol/cm), palmitic acid (0.26-2.03 nmol/cm), and stearic acid (0.34-1.81 nmol/cm). Significant differences depending on caries activity were detected neither in saliva nor in the corresponding pellicle samples.
Topics: Acetic Acid; Case-Control Studies; Child; Child, Preschool; Chromatography, Liquid; Dental Caries; Dental Pellicle; Glycine; Humans; Male; Metabolomics; Propionates; Saliva; Tandem Mass Spectrometry
PubMed: 31959821
DOI: 10.1038/s41598-020-57531-8 -
Frontiers in Public Health 2019The objective of this systematic review was to assess the scope and breadth of publicly available prospective cohort and randomized controlled trial (RCT) literature on...
The objective of this systematic review was to assess the scope and breadth of publicly available prospective cohort and randomized controlled trial (RCT) literature on 100% fruit juice and dental caries or tooth erosion in humans. We performed a systematic search in MEDLINE/PubMed, EMBASE, and Web of Science for studies published from inception through May 2018, and the Cochrane Library databases for reports published through January 2018. Prospective cohort studies or RCTs conducted on dental health and 100% fruit juice, and published in English were selected. No restrictions were set for age, sex, geographic location, or socioeconomic status. Eight publications representing five independent prospective cohort studies and nine publications on nine RCTs were included. All prospective cohort studies were in children or adolescents, and all RCTs were in adults. Prospective cohort studies on tooth erosion found no association between juice intake and tooth erosion, while those on dental caries incidence reported either no association or an inverse association between 100% fruit juice intakes and dental caries incidence. RCTs on tooth erosion showed decreased microhardness, increased surface enamel loss, increased erosion depth, greater enamel softening, and/or increased pellicle layer with 100% fruit juice, and those on dental caries showed increased demineralization of enamel slabs with 100% fruit juice. The existing evidence on 100% fruit juice intake and caries and tooth erosion are not conclusive. Overall, prospective cohort studies in children and adolescents found no association between 100% fruit juice intake and tooth erosion or dental caries, but, RCT data in adults suggests that 100% fruit juice could contribute to tooth erosion and dental caries. The RCT data, however, were from small, short-term studies that utilized intra-oral devices generally devoid of normal plaque or saliva action, and generally employed conditions that are not reflective of normal juice consumption.
PubMed: 31355175
DOI: 10.3389/fpubh.2019.00190 -
Caries Research 2004Saliva is essential for a lifelong conservation of the dentition. Various functions of saliva are implicated in the maintenance of oral health and the protection of our... (Review)
Review
Saliva is essential for a lifelong conservation of the dentition. Various functions of saliva are implicated in the maintenance of oral health and the protection of our teeth: (i) The tooth surface is continuously protected against wear by a film of salivary mucins and proline-rich glycoprotein. (ii) The early pellicle proteins, proline-rich proteins and statherin, promote remineralization of the enamel by attracting calcium ions. (iii) Demineralization is retarded by the pellicle proteins, in concert with calcium and phosphate ions in saliva and in the plaque fluid. (iv) Several salivary (glyco)proteins prevent the adherence of oral microorganisms to the enamel pellicle and inhibit their growth. (v) The salivary bicarbonate/carbonate buffer system is responsible for rapid neutralization of acids. An overview is presented on the major antimicrobial systems in human saliva. Not only the well-known major salivary glycoproteins, including mucins, proline-rich glycoprotein and immunoglobulins, but also a number of minor salivary (glyco)proteins, including agglutinin, lactoferrin, cystatins and lysozyme, are involved in the first line of defense in the oral cavity. Besides, small cationic antimicrobial peptides, e.g. defensins, cathelicidin and the histatins, have come into focus. These are potentially suited as templates for the design of a new generation of antibiotics, since they kill a broad spectrum of microorganisms, while hardly evoking resistance, in contrast to the classical antibiotics.
Topics: Antimicrobial Cationic Peptides; Buffers; Cariostatic Agents; Dental Caries; Dental Pellicle; Glycoproteins; Humans; Salivary Proteins and Peptides
PubMed: 15153696
DOI: 10.1159/000077762 -
International Journal of Molecular... Sep 2023Hydrophilicity/hydrophobicity-or wettability-is a key surface characterization metric for titanium used in dental and orthopedic implants. However, the effects of...
Hydrophilicity/hydrophobicity-or wettability-is a key surface characterization metric for titanium used in dental and orthopedic implants. However, the effects of hydrophilicity/hydrophobicity on biological capability remain uncertain, and the relationships between surface wettability and other surface parameters, such as topography and chemistry, are poorly understood. The objective of this study was to identify determinants of surface wettability of titanium and establish the reliability and validity of the assessment. Wettability was evaluated as the contact angle of ddHO. The age of titanium specimens significantly affected the contact angle, with acid-etched, microrough titanium surfaces becoming superhydrophilic immediately after surface processing, hydrophobic after 7 days, and hydrorepellent after 90 days. Similar age-related loss of hydrophilicity was also confirmed on sandblasted supra-micron rough surfaces so, regardless of surface topography, titanium surfaces eventually become hydrophobic or hydrorepellent with time. On age-standardized titanium, surface roughness increased the contact angle and hydrophobicity. UV treatment of titanium regenerated the superhydrophilicity regardless of age or surface roughness, with rougher surfaces becoming more superhydrophilic than machined surfaces after UV treatment. Conditioning titanium surfaces by autoclaving increased the hydrophobicity of already-hydrophobic surfaces, whereas conditioning with 70% alcohol and hydrating with water or saline attenuated pre-existing hydrophobicity. Conversely, when titanium surfaces were superhydrophilic like UV-treated ones, autoclaving and alcohol cleaning turned the surfaces hydrorepellent and hydrophobic, respectively. UV treatment recovered hydrophilicity without exception. In conclusion, surface roughness accentuates existing wettability and can either increase or decrease the contact angle. Titanium must be age-standardized when evaluating surface wettability. Surface conditioning techniques significantly but unpredictably affect existing wettability. These implied that titanium wettability is significantly influenced by the hydrocarbon pellicle and other contaminants inevitably accumulated. UV treatment may be an effective strategy to standardize wettability by making all titanium surfaces superhydrophilic, thereby allowing the characterization of individual surface topography and chemistry parameters in future studies.
Topics: Wettability; Titanium; Surface Properties; Reproducibility of Results; Hydrophobic and Hydrophilic Interactions; Microscopy, Electron, Scanning; Dental Implants
PubMed: 37834133
DOI: 10.3390/ijms241914688