-
Oral Health & Preventive Dentistry Jan 2021Grape-seed extract (GSE) contains polyphenols that readily adhere to proteins and modify the acquired enamel pellicle (AEP). The first step in biofilm formation is...
PURPOSE
Grape-seed extract (GSE) contains polyphenols that readily adhere to proteins and modify the acquired enamel pellicle (AEP). The first step in biofilm formation is bacterial adhesion to the AEP-covered enamel. The aim of this in vitro study was to test whether AEP modification with GSE, fluoride (F-), or their combination (GSE+F-) modulates bacterial adhesion, biofilm metabolism and composition, or cariogenic demineralisation of the enamel.
MATERIALS AND METHODS
The study comprised 3 parts: 1) single-strain Streptococcus gordonii species, 2) a five-species biofilm model, or 3) biofilm (re-)formation using the five-species biofilm model after removal of initial biofilm with toothbrushing. Human whole-mouth stimulated saliva was used to form an AEP on human enamel specimens. The AEP was incubated in water (control), or modified with GSE, F-, or GSE+F-. Bacterial adhesion, biofilm diversity, metabolic activity, biofilm mass, and cariogenic demineralisation (surface hardness) of enamel were assessed after incubation in bacterial broths after 4 h or 22 h. Differences between groups were analysed with one-way ANOVA and post-hoc Bonferroni tests.
RESULTS
GSE and GSE+F- statistically significantly decreased single-strain S. gordonii adhesion, but had no relevant influence when the five-species biofilm model was used. In the biofilm (re-)formation model, GSE reduced bacterial adhesion compared to GSE+F-, while F- caused less cariogenic demineralisation than was found in the control group.
CONCLUSION
AEP modified with GSE retards S. gordonii adhesion, but it does not influence the formation, metabolism and composition of a cariogenic multi-species biofilm.
Topics: Bacterial Adhesion; Biofilms; Dental Pellicle; Grape Seed Extract; Humans; Vitis
PubMed: 34057340
DOI: 10.3290/j.ohpd.b1453013 -
Scientific Reports May 2021DNA is basically an intracellular molecule that stores genetic information and carries instructions for growth and reproduction in all cellular organisms. However, in... (Comparative Study)
Comparative Study
DNA is basically an intracellular molecule that stores genetic information and carries instructions for growth and reproduction in all cellular organisms. However, in some bacteria, DNA has additional roles outside the cells as extracellular DNA (eDNA), which is an essential component of biofilm formation and hence antibiotic tolerance. Mycobacteria include life-threating human pathogens, most of which are slow growers. However, little is known about the nature of pathogenic mycobacteria's eDNA. Here we found that eDNA is present in slow-growing mycobacterial pathogens, such as Mycobacterium tuberculosis, M. intracellulare, and M. avium at exponential growth phase. In contrast, eDNA is little in all tested rapid-growing mycobacteria. The physiological impact of disrupted eDNA on slow-growing mycobacteria include reduced pellicle formation, floating biofilm, and enhanced susceptibility to isoniazid and amikacin. Isolation and sequencing of eDNA revealed that it is identical to the genomic DNA in M. tuberculosis and M. intracellulare. In contrast, accumulation of phage DNA in eDNA of M. avium, suggests that the DNA released differs among mycobacterial species. Our data show important functions of eDNA necessary for biofilm formation and drug tolerance in slow-growing mycobacteria.
Topics: Amikacin; Anti-Bacterial Agents; Antitubercular Agents; Biofilms; DNA, Bacterial; DNA, Viral; Extracellular Fluid; Isoniazid; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Prophages; Species Specificity; Whole Genome Sequencing
PubMed: 34040029
DOI: 10.1038/s41598-021-90156-z -
Clinical Oral Investigations Nov 2021This in situ study aimed to determine and compare the chlorhexidine (CHX) retention in the oral cavity after the application of different CHX pharmaceutical regimens.
OBJECTIVES
This in situ study aimed to determine and compare the chlorhexidine (CHX) retention in the oral cavity after the application of different CHX pharmaceutical regimens.
METHODS
Five volunteers used different CHX treatment regimens including mouth rinses, dental spray and toothpaste gel. After the application of the different CHX regimens, 2-μl samples were taken from saliva and buccal mucosa pellicle as well as the dental pellicle samples formed on standardized enamel surfaces. Sample collection was conducted at six time points within 12 h. Retention of CHX was measured using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.
RESULTS
CHX retention values in the oral mucosa pellicle were significantly higher than those in saliva. CHX remained in the mucosal pellicle at microgrammes per millilitre levels for 12 h after mouth rinsing, 10 h after spray application and 2 h after using the toothpaste. CHX was detected in the dental pellicle for at least 12 h after application of mouth rinsing and spray. Retention of CHX after mouth rinsing or spray application was significantly higher than the retention after using toothpaste.
CONCLUSIONS
Oral mucosa was the favourable site for CHX retention. Higher mouth rinse concentration and longer rinsing time produced a slight increase in CHX retention. CHX spray provided considerable retention values, whereas toothpaste gel delivered the lowest retention after application. MALDI-TOF was a sensitive method with excellent limits of quantification for CHX detection.
Topics: Anti-Infective Agents, Local; Chlorhexidine; Humans; Mouth; Mouthwashes; Saliva; Toothpastes
PubMed: 33825020
DOI: 10.1007/s00784-021-03910-y -
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 -
Mucin O-glycans suppress quorum-sensing pathways and genetic transformation in Streptococcus mutans.Nature Microbiology May 2021Mucus barriers accommodate trillions of microorganisms throughout the human body while preventing pathogenic colonization. In the oral cavity, saliva containing the...
Mucus barriers accommodate trillions of microorganisms throughout the human body while preventing pathogenic colonization. In the oral cavity, saliva containing the mucins MUC5B and MUC7 forms a pellicle that coats the soft tissue and teeth to prevent infection by oral pathogens, such as Streptococcus mutans. Salivary mucin can interact directly with microorganisms through selective agglutinin activity and bacterial binding, but the extent and basis of the protective functions of saliva are not well understood. Here, using an ex vivo saliva model, we identify that MUC5B is an inhibitor of microbial virulence. Specifically, we find that natively purified MUC5B downregulates the expression of quorum-sensing pathways activated by the competence stimulating peptide and the sigX-inducing peptide. Furthermore, MUC5B prevents the acquisition of antimicrobial resistance through natural genetic transformation, a process that is activated through quorum sensing. Our data reveal that the effect of MUC5B is mediated by its associated O-linked glycans, which are potent suppressors of quorum sensing and genetic transformation, even when removed from the mucin backbone. Together, these results present mucin O-glycans as a host strategy for domesticating potentially pathogenic microorganisms without killing them.
Topics: Dental Caries; Host-Pathogen Interactions; Humans; Mucin-5B; Polysaccharides; Quorum Sensing; Saliva; Streptococcus mutans; Transformation, Bacterial; Virulence
PubMed: 33737747
DOI: 10.1038/s41564-021-00876-1 -
Oral Health & Preventive Dentistry Jan 2021The topical fluoride treatment of teeth can lead to a formation of CaF2-like material, which is considered to play a significant role in caries prevention....
The topical fluoride treatment of teeth can lead to a formation of CaF2-like material, which is considered to play a significant role in caries prevention. Different types of fluoride sources are applied. The aim of this study was to analyse the in vitro fluoridation effect of the lesser known organic fluoride compound nicomethanol hydrofluoride (NH) regarding fluoride accumulation and morphological changes on dental enamel surfaces. Materials and Methods: The fluoridation effect was investigated by scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX) after treatment with fluoride solutions at a concentration of 1350 ppm F - and a pH value of 5.5. NH was tested against inorganic sodium fluoride (NaF) as reference. Fluoridation was done on pellicle-free and pellicle-covered enamel. Results: Formation of globular CaF2-like material was observed for both fluoride types. However, NH led to considerably higher calcium fluoride accumulation on the enamel surface as shown by both EDX and SEM. The globule diameters varied between 0.2 and 0.8 µm. Cross-sectional analysis revealed that the globular precipitates lay directly on the enamel surface; only the very surface-near volume was affected. No statistically significant difference of the fluoridation effect was measured with vs without saliva pre-treatment. Conclusion: The experiments showed a 6 times greater F - surface uptake on dental enamel with NH compared to sodium fluoride, thus suggesting an important role of NH during remineralization phases, fostering equilibrium between de- and remineralization.
Topics: Calcium Fluoride; Dental Enamel; Fluorides; Fluorides, Topical; Humans; Nicotinyl Alcohol; Sodium Fluoride
PubMed: 33491379
DOI: 10.3290/j.ohpd.b898957 -
Colloids and Surfaces. B, Biointerfaces Apr 2021The salivary pellicle, an adlayer formed by adsorption of salivary components on teeth and dental biomaterials, has direct consequences on basic outcomes of dentistry.... (Review)
Review
The salivary pellicle, an adlayer formed by adsorption of salivary components on teeth and dental biomaterials, has direct consequences on basic outcomes of dentistry. Here, we provide an overview of salivary pellicle formation processes with a critical focus on dental biomaterials. We describe and critique the array of salivary pellicle measurement techniques. We also discuss factors that may affect salivary pellicle formation and the heterogeneity of the published literature describing salivary pellicle formation on dental biomaterials. Finally, we survey the many effects salivary pellicles have on dental biomaterials and highlight its implications on design criteria for dental biomaterials. Future investigations may lead to rationally designed dental biomaterials to control the salivary pellicle and enhance material function and patient outcomes.
Topics: Adsorption; Biocompatible Materials; Dental Pellicle; Humans; Saliva; Salivary Proteins and Peptides; Surface Properties
PubMed: 33460965
DOI: 10.1016/j.colsurfb.2021.111570 -
International Journal of Molecular... Dec 2020is the main early colonizing cariogenic bacteria because it recognizes salivary pellicle receptors. The Antigen I/II (Ag I/II) of is among the most important adhesins...
is the main early colonizing cariogenic bacteria because it recognizes salivary pellicle receptors. The Antigen I/II (Ag I/II) of is among the most important adhesins in this process, and is involved in the adhesion to the tooth surface and the bacterial co-aggregation in the early stage of biofilm formation. However, this protein has not been used as a target in a virtual strategy search for inhibitors. Based on the predicted binding affinities, drug-like properties and toxicity, molecules were selected and evaluated for their ability to reduce adhesion. A virtual screening of 883,551 molecules was conducted; cytotoxicity analysis on fibroblast cells, adhesion studies, scanning electron microscopy analysis for bacterial integrity and molecular dynamics simulation were also performed. We found three molecules ZINC19835187 (ZI-187), ZINC19924939 (ZI-939) and ZINC19924906 (ZI-906) without cytotoxic activity, which inhibited about 90% the adhesion of to polystyrene microplates. Molecular dynamic simulation by 300 nanoseconds showed stability of the interaction between ZI-187 and Ag I/II (PDB: 3IPK). This work provides new molecules that targets Ag I/II and have the capacity to inhibit in vitro the adhesion on polystyrene microplates.
Topics: Antigens, Bacterial; Bacterial Adhesion; Bacterial Proteins; Biofilms; Cells, Cultured; Computer Simulation; Fibroblasts; Humans; In Vitro Techniques; Periodontal Ligament; Small Molecule Libraries; Streptococcus mutans
PubMed: 33396525
DOI: 10.3390/ijms22010377 -
Journal of Dentistry Feb 2021To investigate the modification of the salivary pellicle with different polyphenol-rich teas and natural extracts for the protection against dental erosion.
OBJECTIVE
To investigate the modification of the salivary pellicle with different polyphenol-rich teas and natural extracts for the protection against dental erosion.
METHODS
We performed two experiments: one with teas (Green tea, Black tea, Peppermint tea, Rosehip tea, negative control [NC]) and other with natural extracts (Grape seed, Grapefruit seed, Cranberry, Propolis, NC), where NC was deionized water. A total of 150 enamel specimens were used (n = 15/group). Both experiments followed the same design, consisting of 5 cycles of: salivary pellicle formation (30 min, 37 °C), modification with the solutions (30 min, 25 °C), further salivary pellicle formation (60 min, 37 °C) and erosive challenge (1 min, 1% citric acid, pH 3.6). Relative surface microhardness (rSMH), relative surface reflection intensity (rSRI) and amount of calcium release (CaR) were evaluated. Data were analysed with Kruskal-Wallis and Wilcoxon rank sum tests with Bonferroni correction (α = 0.05).
RESULTS
Regarding teas, Black and Green teas showed the best protection against dental erosion, presenting higher rSMH and lower CaR than NC. Peppermint tea was not different to NC and Rosehip tea caused erosion, showing the highest CaR and greatest loss of SMH and SRI. Regarding natural extracts, Grape seed and Grapefruit seed extracts presented the best protective effect, with significantly higher rSMH and lower CaR. Cranberry caused significantly more demineralization; and Propolis did not differ from NC.
CONCLUSION
Green tea, Black tea, Grape seed extract and Grapefruit seed extract were able to modify the salivary pellicle and improve its protective effect against enamel erosion, but Rosehip tea and Cranberry extract caused erosion.
CLINICAL RELEVANCE
Some some bio-products, such as teas and natural extracts, improve the protective effect of the salivary pellicle against enamel erosion. More studies should be performed in order to test the viability of their use as active ingredients for oral care products.
Topics: Dental Enamel; Dental Pellicle; Humans; Plant Extracts; Polyphenols; Tooth Erosion
PubMed: 33387569
DOI: 10.1016/j.jdent.2020.103567 -
Journal of Dental Sciences Jan 2021As soon as saliva contacts the teeth surface, salivary proteins adhere to the tooth surface to form acquired salivary pellicle. The formation of this acquired salivary... (Review)
Review
As soon as saliva contacts the teeth surface, salivary proteins adhere to the tooth surface to form acquired salivary pellicle. The formation of this acquired salivary pellicle is a dynamic and selective process of macromolecular adsorption and desorption. Although acquired salivary pellicle contains proteins and peptides, it also contains lipids, and other macro-molecules, all of which contribute to its protective properties. Acquired salivary pellicle is related to the development of common oral diseases, such as erosion, dental caries, and periodontal disease. Acquired salivary pellicle acts as a natural barrier to prevent a tooth's surface from making direct contact with acids and to protect it from erosive demineralization. It contributes to the control of dental erosion by modulating calcium and phosphate concentrations on the tooth surface. It also influences the initial colonizer of oral biofilm and affects the transportation pathway of the acidic products of cariogenic bacteria, which affects the development of dental caries. In addition, it influences periodontal disease by acting on the colonization of periodontal pathogens. This paper's aim is to provide an overview of the acquired salivary pellicle, highlighting its composition, structure, function, role in common oral diseases, and modification for the prevention of oral diseases.
PubMed: 33384841
DOI: 10.1016/j.jds.2020.10.007