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International Journal of Molecular... Nov 2020Biofilms are formed on surfaces inside the oral cavity covered by the acquired pellicle and develop into a complex, dynamic, microbial environment. Oral biofilm is a... (Review)
Review
Biofilms are formed on surfaces inside the oral cavity covered by the acquired pellicle and develop into a complex, dynamic, microbial environment. Oral biofilm is a causative factor of dental and periodontal diseases. Accordingly, novel materials that can resist biofilm formation have attracted significant attention. Zwitterionic polymers (ZPs) have unique features that resist protein adhesion and prevent biofilm formation while maintaining biocompatibility. Recent literature has reflected a rapid increase in the application of ZPs as coatings and additives with promising outcomes. In this review, we briefly introduce ZPs and their mechanism of antifouling action, properties of human oral biofilms, and present trends in anti-biofouling, zwitterionic, dental materials. Furthermore, we highlight the existing challenges in the standardization of biofilm research and the future of antifouling, zwitterated, dental materials.
Topics: Bacterial Adhesion; Biocompatible Materials; Biofilms; Dental Materials; Humans; Mouth; Polymers
PubMed: 33260367
DOI: 10.3390/ijms21239087 -
Journal of Colloid and Interface Science Feb 2021Salivary pellicles i.e., thin films formed upon selective adsorption of saliva, protect oral surfaces against chemical and mechanical insults. Pellicles are also...
HYPOTHESIS
Salivary pellicles i.e., thin films formed upon selective adsorption of saliva, protect oral surfaces against chemical and mechanical insults. Pellicles are also excellent aqueous lubricants. It is generally accepted that reconstituted pellicles have a two-layer structure, where the outer layer is mainly composed of MUC5B mucins. We hypothesized that by comparing the effect of ionic strength on reconstituted pellicles and MUC5B films we could gain further insight into the pellicle structure.
EXPERIMENTS
Salivary pellicles and MUC5B films reconstituted on solid surfaces were investigated at different ionic strengths by Force Spectroscopy, Quartz Crystal Microbalance with Dissipation, Null Ellipsometry and Neutron Reflectometry.
FINDINGS
Our results support the two-layer structure for reconstituted salivary pellicles. The outer layer swelled when ionic strength decreased, indicating a weak polyelectrolyte behavior. While initially the MUC5B films exhibited a similar tendency, this was followed by a drastic collapse indicating an interaction between exposed hydrophobic domains. This suggests that mucins in the pellicle outer layer form complexes with other salivary components that prevent this interaction. Lowering ionic strength below physiological values also led to a partial removal of the pellicle inner layer. Overall, our results highlight the importance that the interactions of mucins with other pellicle components play on their structure.
Topics: Adsorption; Dental Pellicle; Mucin-5B; Mucins; Saliva
PubMed: 33198975
DOI: 10.1016/j.jcis.2020.10.124 -
International Journal of Molecular... Nov 2020This work aimed to compare the capability of to adhere to a novel surface, double-etched titanium (DAE), in respect to machined and single-etched titanium. The...
This work aimed to compare the capability of to adhere to a novel surface, double-etched titanium (DAE), in respect to machined and single-etched titanium. The secondary outcome was to establish which topographical features could affect the interaction between the implant surface and bacteria. The samples' superficial features were characterized using scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS), and the wetting properties were tested through sessile methods. The novel surface, the double-etched titanium (DAE), was also analyzed with atomic force microscopy (AFM). was inoculated on discs previously incubated in saliva, and then the colony-forming units (CFUs), biomass, and cellular viability were measured at 24 and 48h. SEM observation showed that DAE was characterized by higher porosity and Oxygen (%) in the superficial layer and the measurement of the wetting properties showed higher hydrophilicity. AFM confirmed the presence of a higher superficial nano-roughness. Microbiological analysis showed that DAE discs, coated by pellicle's proteins, were characterized by significantly lower CFUs at 24 and 48 h with respect to the other two groups. In particular, a significant inverse relationship was shown between the CFUs at 48 h and the values of the wetted area and a direct correlation with the water contact angle. The biomass at 24 h was slightly lower on DAE, but results were not significant concerning the other groups, both at 24 and 48 h. The DAE treatment not only modifies the superficial topography and increased hydrophilicity, but it also increases the Oxygen percentage in the superficial layer, which could contribute to the inhibition of adhesion. DAE can be considered a promising treatment for titanium implants to counteract a colonization pioneer microorganism, such as
Topics: Adhesives; Bacteria; Bacterial Adhesion; Biofilms; Coated Materials, Biocompatible; Dental Implants; Humans; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Spectrometry, X-Ray Emission; Streptococcus oralis; Surface Properties; Titanium
PubMed: 33167597
DOI: 10.3390/ijms21218315 -
Biomaterial Investigations in Dentistry Oct 2020To investigate if differences in titanium implant surface topography influence biofilm formation.
OBJECTIVES
To investigate if differences in titanium implant surface topography influence biofilm formation.
MATERIALS AND METHODS
Titanium discs were prepared and characterized using a profilometer: Group A ( 0.15 µm, smooth), Group B ( 0.64 µm, minimally rough) and Group C ( 1.3 µm, moderately rough). Contact angle and surface free energy (SFE) were determined for each group. Non-preconditioned titanium discs were incubated with for 24 h. In additional experiments, the titanium discs were initially coated with human saliva, bovine serum albumin or phosphate-buffered saline for 2 h before incubation with for 24 h. The amount of fungal biofilm formation was quantified using a colorimetric assay.
RESULTS
biofilm formation was significantly lower ( < 0.05) on the minimally rough titanium surface compared to smooth and moderately rough surfaces. The titanium surface displaying the lowest SFE (Group B) was associated with significantly lower ( < 0.05) biofilm formation than the other two groups. Salivary coating resulted in greater adherence of with increased surface roughness.
CONCLUSIONS
The minimally rough titanium discs displayed lowest SFE compared to smooth and moderately rough surfaces and showed the least biofilm formation. This study demonstrated that biofilm formation increased in a SFE-dependent manner. These findings suggest that SFE might be a more explanatory factor for biofilm formation on titanium surfaces than roughness. The presence of a pellicle coating may negate the impact of SFE on biofilm formation on titanium surfaces.
PubMed: 33134957
DOI: 10.1080/26415275.2020.1829489 -
Dentistry Journal Oct 2020This in vitro study evaluated the effectiveness of a novel dentifrice containing stabilized chlorine dioxide, sodium lauroyl sarcosinate (sarkosyl), and sodium fluoride...
This in vitro study evaluated the effectiveness of a novel dentifrice containing stabilized chlorine dioxide, sodium lauroyl sarcosinate (sarkosyl), and sodium fluoride in enhancing enamel fluoride uptake, remineralization, pellicle cleaning and inhibiting biofilm regrowth. Remineralization was measured by fluoride uptake and surface microhardness assessment tests. Artificial stains were removed and scored based on pellicle cleaning ratio. Biofilm regrowth was measured by counting colonies on the agar plates. All studies were conducted using bovine teeth specimens. The efficacy of Toothpaste C (CloSYS anticavity toothpaste) was compared with United States Pharmacopoeia Reference Dentifrice, Toothpaste B (discontinued CloSYS anticavity toothpaste formulation) and leading commercial toothpastes. The enamel fluoride uptake and remineralization by Toothpaste C was 96.1% to 303.3% and 38.0% to 102.4% higher than the tested toothpastes, respectively. The mean pellicle cleaning ratio of Toothpaste C was similar to American Dental Association Reference Material. Toothpaste C had a significant reduction in regrowth of the oral polymicrobial biofilm compared to the control. All tested toothpastes contained 0.24% sodium fluoride. Toothpaste C exhibited significantly superior performance towards fluoride uptake and remineralization compared to the tested toothpastes. Therefore, toothpaste ingredients other than sodium fluoride accounted for the enhanced fluoride uptake and remineralization.
PubMed: 33121042
DOI: 10.3390/dj8040122 -
Caries Research 2020A combination of the proteins casein and mucin is known to modify the salivary pellicle and improve its protection of the underlying enamel from erosion. It is so far...
AIM
A combination of the proteins casein and mucin is known to modify the salivary pellicle and improve its protection of the underlying enamel from erosion. It is so far not known if this protection is confined solely to erosion, or if it also extends to abrasion, and this in vitro study aimed at investigating this question.
METHODS
A total of 72 human enamel specimens were prepared and randomly assigned to four groups: pellicle (P), casein/mucin (CM), pellicle + casein/mucin (PCM), and control (Ctrl). Each specimen underwent five cycles, each cycle consisting of a pellicle/treatment part, an erosion part (3 min in 1% citric acid, pH 3.6, 25°C, 70 rpm), and an abrasion part (50 toothbrush strokes within 25 s in toothpaste slurry with a 200-g load). The pellicle/treatment part consisted of 2 h of incubation in whole human saliva for group P, 2 h of incubation (25°C, 70 rpm) in a protein mixture of 1% casein and 0.27% mucin for group CM, and 2 h of incubation in saliva followed by 2 h of incubation in the protein mixture for group PCM. The fourth group (Ctrl) served as the control and was kept in a humid chamber without saliva or protein treatment. The enamel surfaces were scanned with an optical profilometer initially and after the final cycle, and surface loss was analyzed. Furthermore, the surface microhardness (SMH) was measured initially, after each pellicle/treatment part and each erosion cycle, and after the final abrasion cycle. The results were analyzed with Kruskal-Wallis and Wilcoxon tests with Bonferroni corrections.
RESULTS
The different treatments did not show differences in surface loss and therefore did not protect enamel from surface loss by abrasion. Nonetheless, we observed differences in the SMH values, namely the Ctrl group being significantly softer than the experimental groups.
CONCLUSION
The observed differences in SMH suggest that a different abrasion protocol could lead to differences in surface loss, and further investigation of whether and under which conditions pellicle modification leads to increased resistance to abrasion remains worthwhile.
Topics: Caseins; Dental Enamel; Dental Pellicle; Humans; Mucins; Tooth Abrasion; Tooth Erosion
PubMed: 33113528
DOI: 10.1159/000510699 -
Clinical Oral Investigations Dec 2020All soft and solid surface structures in the oral cavity are covered by the acquired pellicle followed by bacterial colonization. This applies for natural structures as... (Review)
Review
BACKGROUND
All soft and solid surface structures in the oral cavity are covered by the acquired pellicle followed by bacterial colonization. This applies for natural structures as well as for restorative or prosthetic materials; the adherent bacterial biofilm is associated among others with the development of caries, periodontal diseases, peri-implantitis, or denture-associated stomatitis. Accordingly, there is a considerable demand for novel materials and coatings that limit and modulate bacterial attachment and/or propagation of microorganisms.
OBJECTIVES AND FINDINGS
The present paper depicts the current knowledge on the impact of different physicochemical surface characteristics on bioadsorption in the oral cavity. Furthermore, it was carved out which strategies were developed in dental research and general surface science to inhibit bacterial colonization and to delay biofilm formation by low-fouling or "easy-to-clean" surfaces. These include the modulation of physicochemical properties such as periodic topographies, roughness, surface free energy, or hardness. In recent years, a large emphasis was laid on micro- and nanostructured surfaces and on liquid repellent superhydrophic as well as superhydrophilic interfaces. Materials incorporating mobile or bound nanoparticles promoting bacteriostatic or bacteriotoxic properties were also used. Recently, chemically textured interfaces gained increasing interest and could represent promising solutions for innovative antibioadhesion interfaces. Due to the unique conditions in the oral cavity, mainly in vivo or in situ studies were considered in the review.
CONCLUSION
Despite many promising approaches for modulation of biofilm formation in the oral cavity, the ubiquitous phenomenon of bioadsorption and adhesion pellicle formation in the challenging oral milieu masks surface properties and therewith hampers low-fouling strategies.
CLINICAL RELEVANCE
Improved dental materials and surface coatings with easy-to-clean properties have the potential to improve oral health, but extensive and systematic research is required in this field to develop biocompatible and effective substances.
Topics: Bacterial Adhesion; Biofilms; Dental Pellicle; Mouth; Surface Properties
PubMed: 33111157
DOI: 10.1007/s00784-020-03646-1 -
Archives of Oral Biology Nov 2020In the present study, we used an in vitro initial intrinsic erosion model to evaluate: (experiment 1) the influence of the degree of serine (Ser) phosphorylation of...
OBJECTIVES
In the present study, we used an in vitro initial intrinsic erosion model to evaluate: (experiment 1) the influence of the degree of serine (Ser) phosphorylation of peptides containing the 15 N-terminal residues of statherin and (experiment 2) the effect of different concentrations of the peptide with the best performance in experiment 1 on initial enamel erosion.
DESIGN
Bovine enamel specimens were divided into 6 groups (n = 15/group) for each experiment. In experiment 1, the peptides evaluated (at 1.88 × 10 M) were: not phosphorylated (StatSS), phosphorylated in Ser2 (StatpSS), phosphorylated in Ser3 (StatSpS) phosphorylated in Ser2 and Ser3 (StatpSpS). Phosphate buffer and human recombinant statherin were used as negative and positive controls, respectively. In experiment 2, StatpSpS was evaluated at different concentrations: 0.94, 1.88, 3.76 and 7.52 × 10 M. Phosphate buffer and 0.1 mg/mL CaneCPI-5 were employed as negative and positive controls, respectively. In each experiment, the specimens were incubated with the solutions for 2 h, then the AEP was allowed to form (under human pooled saliva) for 2 h. The specimens were then challenged with 0.01 M HCl for 10 s. Demineralization was evaluated by percentage of surface hardness change (%SHC). Data were analyzed by ANOVA and Tukey's test (p < 0.05).
RESULTS
In experiment 1, only StatpSpS significantly reduced the % SHC in comparison with control. In experiment 2, 1.88 × 10 M StatpSpS significantly reduced the %SHC in comparison with control.
CONCLUSIONS
This is the first study showing that statherin-derived peptide might protect against intrinsic erosion.
Topics: Animals; Cattle; Dental Enamel; Humans; In Vitro Techniques; Phosphorylation; Saliva; Salivary Proteins and Peptides; Serine; Tooth Erosion
PubMed: 32919104
DOI: 10.1016/j.archoralbio.2020.104890 -
Microbiology and Immunology Nov 2020Abiotrophia defectiva is a species of nutritionally variant streptococci that is found in human saliva and dental plaques and that has been associated with infective...
Abiotrophia defectiva adhere to saliva-coated hydroxyapatite beads via interactions between salivary proline-rich-proteins and bacterial glyceraldehyde-3-phosphate dehydrogenase.
Abiotrophia defectiva is a species of nutritionally variant streptococci that is found in human saliva and dental plaques and that has been associated with infective endocarditis. In our previous study, it was found that A. defectiva could bind specifically to saliva-coated hydroxyapatite beads (SHA). This study identified a cell surface component of A. defectiva that promotes adherence to SHA beads. The binding of A. defectiva to SHA was reduced in the presence of antibodies against human proline-rich protein (PRP); these results suggested that PRP may be a critical component mediating interactions between A. defectiva and the salivary pellicle. Two-dimensional gel electrophoresis of whole A. defectiva cells followed by Far-Western blotting was conducted by probing with synthetic peptides analogous to the binding region of PRP known as PRP-C. The results indicate that an A. defectiva protein of 37 kDa interacts with PRP-C. The results of amino-terminal sequencing of the adhesive A. defectiva protein revealed significant similarity to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Recombinant GAPDH bound to immobilized PRP-C in a dose-dependent manner and binding of A. defectiva to SHA or to PRP was reduced in the presence of anti-GAPDH antiserum. Western blotting or electron immunomicroscopic observations with anti-GAPDH antiserum revealed that this protein was expressed in both cytosolic and cell wall fractions. These results suggest that A. defectiva could specifically bind to PRP via interactions with cell surface GAPDH; the findings suggest a mechanism underlying A. defectiva-mediated adherence to saliva-coated tooth surfaces.
Topics: Abiotrophia; Amino Acid Sequence; Bacterial Adhesion; Durapatite; Escherichia coli; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Peptides; Proline; Saliva; Salivary Proline-Rich Proteins; Streptococcus
PubMed: 32918493
DOI: 10.1111/1348-0421.12848 -
Journal of Applied Oral Science :... 2020Saliva is the major contributor for the protein composition of the acquired enamel pellicle (AEP), a bacteria-free organic layer formed by the selective adsorption of...
Saliva is the major contributor for the protein composition of the acquired enamel pellicle (AEP), a bacteria-free organic layer formed by the selective adsorption of salivary proteins on the surface of the enamel. However, the amount of proteins that can be recovered is even smaller under in vitro condition, due to the absence of continuous salivary flow. Objective This study developed an in vitro AEP protocol for proteomics analysis using a new formation technique with different collection solutions. Methodology 432 bovine enamel specimens were prepared (4x4 mm) and divided into four groups (n=108). Unstimulated saliva was provided by nine subjects. The new AEP formation technique was based on saliva resupply by a new one every 30 min within 120 minutes at 37ºC under agitation. AEP was collected using an electrode filter paper soaked in the collection solutions according with the group: 1) 3% citric acid (CA); 2) 0.5% sodium dodecyl sulfate (SDS); 3) CA followed by SDS (CA+SDS); 4) SDS followed by CA (SDS+CA). The pellicles collected were processed for analysis through LC-ESI-MS/MS technique. Results A total of 55 proteins were identified. The total numbers of proteins identified in each group were 40, 21, 28 and 41 for the groups CA, SDS, CA+SDS and SDS+CA, respectively. Twenty-three typical AEP proteins were identified in all groups, but Mucin was only found in CA and CA+SDS, while three types of PRP were not found in the SDS group. Moreover, a typical enamel protein, Enamelin, was identified in the CA+SDS group only. Conclusion The new technique of the in vitro AEP formation through saliva replacement was essential for a higher number of the proteins identified. In addition, considering practicality, quantity and quality of identified proteins, citric acid seems to be the best solution to be used for collection of AEP proteins.
Topics: Animals; Cattle; Dental Enamel; Dental Pellicle; Proteome; Proteomics; Saliva; Salivary Proteins and Peptides; Tandem Mass Spectrometry
PubMed: 32785522
DOI: 10.1590/1678-7757-2020-0189