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Journal of the Mechanical Behavior of... Feb 2024Chitosan (Ch) is a naturally occurring biocompatible and bio-degradable material with high corrosion protective capacities for metals in various corrosive media....
Chitosan (Ch) is a naturally occurring biocompatible and bio-degradable material with high corrosion protective capacities for metals in various corrosive media. Hydroxyapatite (HA) is a significant biodegradable and bioactive material. In the present work, chitosan-hydroxyapatite (Ch-HA) composite coatings with various concentrations of chitosan were made on 316L stainless steel (316L SS) using sol-gel dip coating technique. The coatings were characterized by X-ray diffraction (XRD), FTIR, SEM, and electrochemical measurements. The surface morphology results (SEM) of coated implants exposed the fairly dense microstructures having uniformity without cracks and pores indicating that coating was successfully deposited. From electrochemical analyses, it was observed that the value of corrosion current density and the corrosion rate decreased from 6.03 to 0.15 and 5.56-0.13 respectively indicating that 1.5gCh-HA is the best coating concentration. The electrochemical results demonstrated an improvement in the corrosion resistance of 316L SS than the bare one. The decrease in slope and loop area of cyclic voltammograms reveals about improvement in corrosion resistance. This increment in corrosion resistance of the Ch-HA coated SS implant in the artificial saliva is as 1.5gCh-HA > 2gCh-HA >1gCh-HA >0.5gCh-HA. Furthermore, Ch-HA coatings revealed appropriate adhesion with 316L SS substrate for its use in dental implants.
Topics: Durapatite; Chitosan; Dental Implants; Coated Materials, Biocompatible; Corrosion; Materials Testing; Surface Properties
PubMed: 38039776
DOI: 10.1016/j.jmbbm.2023.106268 -
Photodiagnosis and Photodynamic Therapy Dec 2023Adhesive remnants post-orthodontic treatment might have deleterious effects on oral health, including enamel demineralization, plaque accumulation, and elevated risk of...
BACKGROUND
Adhesive remnants post-orthodontic treatment might have deleterious effects on oral health, including enamel demineralization, plaque accumulation, and elevated risk of caries development. The aim of this study was to identify and characterize adhesive residues in an ex vivo environment rich in salivary microbiota using quantitative light-induced fluorescence (QLF) technology.
METHODS
Disc-shaped adhesive samples with thickness ranging from 800 to 100 µm were prepared using GC Ortho, GOTO, T Orthobond, and Transbond XT and subsequently evaluated utilizing a QLF system. Bovine teeth containing GC Ortho and GOTO adhesives and isolated human premolar teeth bonded with brackets were subjected to a 10-day incubation in an artificial saliva environment. Daily imaging was conducted using QLF during incubation. Data with ΔR > 30% and simple hygiene score (SHS) were obtained with a software for further analysis.
RESULTS
Fluorescence intensity exhibited significant differences among the four orthodontic adhesives (p < 0.05). Results of incubation in artificial saliva revealed that red fluorescence surrounding the adhesive on the tooth surface was distinctly observable from day five onwards, with ΔR > 30% and SHS levels higher than those of the control group without adhesive (p < 0.05). Observation of fluorescence images of isolated human premolar teeth with bonded brackets indicated that red fluorescence was primarily present around the brackets.
CONCLUSIONS
Application of QLF is efficacious in identifying and demarcating adhesive residues within an environment rich in salivary microbiota.
Topics: Humans; Animals; Cattle; Saliva, Artificial; Quantitative Light-Induced Fluorescence; Orthodontic Brackets; Photochemotherapy; Photosensitizing Agents
PubMed: 37567330
DOI: 10.1016/j.pdpdt.2023.103743 -
International Journal of Dentistry 2023Daily use of different mouthrinses at home or in the dental office can alter the properties of resin hardness. The present study aimed to compare Vickers microhardness...
INTRODUCTION
Daily use of different mouthrinses at home or in the dental office can alter the properties of resin hardness. The present study aimed to compare Vickers microhardness (VHN) of nanohybrid composite resins (NCRs) immersed in mouthrinses.
MATERIALS AND METHODS
In total, 120 discs (10 ⨯ 2 mm) were prepared from three NCR shade A2 ( = 40/group) with Filtek Z350 XT (Z350XT), Tetric EvoCeram (TEC), and Polofil NHT (PNHT). The specimens were incubated in artificial saliva (37°C ⨯ 24 hr). Specimens were distributed into four mouthrinses ( = 10/group) of artificial saliva (control), chlorhexidine (CHX 0.12%, pH 5.6), cetylpyridine chloride (CPC 0.075%, pH 5.84), and CHX 0.12% + CPC 0.05% (pH 6.2) (2 times/day, 2' ⨯ 12 hr). The VHN (300 gf/10") was measured after 24 hr, 14, and 21 days. Data were analyzed by three-way analysis of variance, followed by post hoc Tukey analysis at 0.05 level of significance.
RESULTS
The results revealed a global effect of the interaction of the mouthrinses ⨯ time between NRC evaluated (=0.001). Baseline VHN in PNHT and Z350XT was higher than TEC. Within each group of NCR, VHN of CHX + CPC > other mouthrinses (PNHT/14 days; Z350XT/21 days), and >CPC (Z350XT/14 days). In mouthrinses-intragroups, VHN of PNHT and Z350XT decreased at 14 days (CHX, CPC) and was maintained over time in NCR (CHX + CPC). VHN-TEC was similar among groups.
CONCLUSION
Microhardness showed differences due to the interaction of the type of NCR, the composition of the mouthrinses, and time. VHN decreased after 14 days and was more affected in composite resins with lower filler content and in mouthrinses with a lower pH.
PubMed: 38021349
DOI: 10.1155/2023/9161639 -
Journal of the Mechanical Behavior of... Aug 2023The aim of this study was to investigate the effect of different polymeric matrices and their crosslink density on the mechanical and tribological properties of three...
The aim of this study was to investigate the effect of different polymeric matrices and their crosslink density on the mechanical and tribological properties of three commercially available dental resin composites, including Filtek Z250XT, Charisma Classic, and Venus Diamond One. The mechanical properties of the composites were investigated by instrumented indentation. The results showed that the polymeric matrix composition has a significant effect on the hardness and elastic modulus of the resins. Wear resistance was investigated by reciprocating ball-on-plane tests in artificial saliva. Results show that the TCD-based resin composite has higher crosslinking density resulting in a more wear-resistant material. There was also a strong correlation between wear resistance and the mechanical properties of the resin composites when comparing similar fillers. These findings suggest that the wear resistance of resin composites can be improved by increasing their crosslinking density and enhancing their mechanical properties. The study provides insights into the design and development of more wear-resistant resin composites for dental applications.
Topics: Materials Testing; Composite Resins; Hardness; Elastic Modulus; Saliva, Artificial; Surface Properties; Dental Materials
PubMed: 37393888
DOI: 10.1016/j.jmbbm.2023.105962 -
Dental Materials : Official Publication... Feb 2024In light of the constantly flowing saliva, anti-caries remineralization agents are inclined to be taken away. Owing to their limited residence time, the remineralization...
OBJECTIVES
In light of the constantly flowing saliva, anti-caries remineralization agents are inclined to be taken away. Owing to their limited residence time, the remineralization effect is not as desirable as expected. Hence, our study aimed to synthesize a novel peptide (DGP) with high affinity to both collagen fibrils and hydroxyapatite, and investigated its dentin remineralization efficacy in vitro and anti-caries capability in vivo.
METHODS
DGP was synthesized through Fmoc solid-phase reaction. The binding ability and interaction mechanism of DGP to demineralized dentin were investigated. Dentin specimens were demineralized, then treated with DGP and deionized water respectively. The specimens were incubated in artificial saliva and in-vitro remineralization effectiveness was analyzed after 14 days. The rat caries model was established to further scrutinize the in-vivo efficacy of caries prevention.
RESULTS
DGP possesses an enhanced adhesion force of 12.29 ± 1.12 nN to demineralized dentin. The favorable adsorption capacity is ascribed to the stable hydrogen bonds between S2P-101 and ASP-100 of DGP and GLY33 and PRO-16 of collagen fibers. Abundant mineral deposits and remarkable tubule occlusion were observed in the DGP group. DGP-treated dentin obtained notable microhardness recovery and higher mineral content after a 14-day remineralization regimen. DGP also demonstrated potent caries prevention in vivo, with substantially fewer carious lesions and significantly lower Keyes scoring.
SIGNIFICANCE
DGP proves to possess a high affinity to demineralized dentin regardless of saliva flowing, thus enhancing remineralization potency significantly in vitro and in vivo, potential for dental caries prevention and combatting initial dentin caries clinically.
Topics: Humans; Dental Caries; Cariostatic Agents; Dentin; Minerals; Collagen; Tooth Remineralization
PubMed: 37989605
DOI: 10.1016/j.dental.2023.11.009 -
Langmuir : the ACS Journal of Surfaces... Oct 2023Cobalt-chromium-molybdenum alloy is used as a material for artificial human body components such as artificial hip joint and artificial denture and is often affected by...
Investigation on the Corrosion Resistance Properties of Cobalt-Chromium-Molybdenum Alloy Artificial Human Body Components with Robust Biomimetic Superhydrophobic and Slippery Surfaces Based on Laser Texturing.
Cobalt-chromium-molybdenum alloy is used as a material for artificial human body components such as artificial hip joint and artificial denture and is often affected by electrochemical corrosion in human body fluids and saliva, which leads to inflammatory reactions and damage to the surrounding tissues as well as loosening and failure of the body components themselves. Few studies have been conducted to prepare corrosion-resistant coatings on the surface of CoCrMo. In this study, we used laser texturing to process a bionic 3D micronanocomposite structure on the surface of CoCrMo and quickly prepared a superhydrophobic and slippery surface coating with excellent corrosion resistance using polydimethylsiloxane solution and silicone oil modification. This surface had ultralow surface adhesion and good robustness of durability and abrasion resistance, reducing bacterial colonization or tissue adhesion and solving the problem of the lack of stability of the superhydrophobic surface. Microgrid grooves and layered nanoparticles were structurally responsible for the variation in wettability. The formation mechanism and composition of the prepared coatings were further analyzed. Electrochemical corrosion experiments were conducted on the surface in simulating body fluid and saliva environments, which showed the enhanced corrosion resistance of the prepared surface in the human body. These findings can further develop the surface functional modification of CoCrMo, accelerating basic and applied research studies on artificial human components.
Topics: Humans; Vitallium; Corrosion; Biomimetics; Human Body; Hydrophobic and Hydrophilic Interactions; Lasers
PubMed: 37782749
DOI: 10.1021/acs.langmuir.3c01861 -
Membranes Jul 2023The development of accessible express methods to determine markers of viral diseases in saliva is currently an actual problem. Novel cross-sensitive sensors based on...
The development of accessible express methods to determine markers of viral diseases in saliva is currently an actual problem. Novel cross-sensitive sensors based on Donnan potential with bio-comparable perfluorosulfonic acid membranes for the determination of salivary viral markers (-acetyl--methionine, -carnitine, and -lysine) were proposed. Membranes were formed by casting from dispersions of Nafion or Aquivion in -methyl-2-pyrollidone or in a mixture of isopropyl alcohol and water. The influence of the polymer equivalent weight and the nature of dispersing liquid on water uptake, ion conductivity, and slope of Donnan potential for the membranes in H and Na form was investigated. The varying of the sorption and transport properties of perfluorosulfonic acid membranes provided a change in the distribution of the sensor sensitivity to -acetyl--methionine, -carnitine, and -lysine ions, which was necessary for multisensory system development. The simultaneous determination of three analytes, and the group analysis of them in artificial saliva solutions, was performed. The errors of -acetyl--methionine and -carnitine determination were 4-12 and 3-11%, respectively. The determination of -lysine was complicated by its interaction with Ca ions. The error of the group analysis was no greater than 9%. The reverse character of the viral markers' sorption by the membranes provided long-term sensor operation.
PubMed: 37623762
DOI: 10.3390/membranes13080701 -
Journal of Dentistry Oct 2023This study aimed at demonstrating the remineralization effect of the enamel around the brackets to aid reduction in white spot lesions (WSLs) with use of zinc-doped...
OBJECTIVES
This study aimed at demonstrating the remineralization effect of the enamel around the brackets to aid reduction in white spot lesions (WSLs) with use of zinc-doped phosphate-based glass (Zn-PBG) containing orthodontic adhesives.
METHODS
Zn-PBG powder was synthesized, and particle morphology, size, and density were evaluated. Orthodontic adhesives with increasing loading percentage of Zn-PBG powder were prepared: ZnPG3 (3 wt.%), ZnPG6 (6 wt.%), and ZnPG9 (9 wt.%). Brackets were bonded on the etched enamel surface and stored in distilled water (DW) for 1 h. Following, Shear bond strength (SBS) along with adhesive remnant index were analyzed. The release of calcium (Ca), phosphorus (P), and zinc (Zn) from adhesive specimens in DW was evaluated after 7, 15 and 30 days of immersion. The remineralization effect was confirmed by microhardness and surface morphology analysis with scanning electron microscopy.
RESULTS
The SBS value was observed between 20 and 22 MPa on enamel surface. The concentration of Ca, P and Zn released in DW increased with loading percentage of Zn-PBG. The microhardness increased in the experimental groups after immersion in artificial saliva for 7 days. Apatite-like crystal formation was observed after 30 days in the ZnPG 9 group.
CONCLUSIONS
The orthodontic adhesive containing Zn-PBG with an optimal SBS performance has an enamel remineralization effect, and therefore can aid in prevention of WSLs.
CLINICAL SIGNIFICANCE
The orthodontic adhesive containing Zn-PBG is clinically advantageous as it can promote remineralization and resist the formation of WSLs that may occur during orthodontic therapy.
Topics: Humans; Dental Cements; Powders; Phosphates; Calcium; Dental Caries
PubMed: 37666468
DOI: 10.1016/j.jdent.2023.104689 -
International Journal of Clinical... Aug 2023(), known as liquorice root is one such herbal remedy that has been shown to have immense potential in the treatment of orofacial diseases.
BACKGROUND
(), known as liquorice root is one such herbal remedy that has been shown to have immense potential in the treatment of orofacial diseases.
AIM
To evaluate the remineralizing potential of liquorice extract on initial enamel carious lesions.
MATERIALS AND METHODS
An and study was conducted, wherein the sound-extracted human premolars were sectioned longitudinally and into enamel blocks of size 4 × 4 mm. Enamel blocks were demineralized to produce artificial carious lesions. study, the demineralized enamel block was exposed to artificial saliva for 5 minutes and artificial saliva containing liquorice for 4 minutes 14 times in a sequential manner. An study was carried out on six volunteers aged between 6 and 12 years. The demineralized enamel block was inserted into the 5 × 5 mm window created on the full palatal coverage appliance. Patients were given commercially available liquorice candies (Ricola) to consume for 7 days twice daily. The remineralization potential of liquorice on demineralized enamel block was assessed using confocal microscopy analysis.
RESULTS
Liquorice extract containing candies showed visual remineralization of the demineralized area on the enamel surface through confocal images.
CONCLUSION
Liquorice extract possesses remineralizing potential with its other medicinal properties. .
HOW TO CITE THIS ARTICLE
Pooja HR, Nagar P, Mascarenhas AN, Effect of Liquorice Candies on Remineralization of Initial Enamel Carious Lesion. Int J Clin Pediatr Dent 2023;16(S-1):S33-S38.
PubMed: 37663213
DOI: 10.5005/jp-journals-10005-2619 -
Photochemistry and Photobiology 2023The highly transmittable nature of SARS-CoV-2 has increased the necessity for novel strategies to safely decontaminate public areas. This study investigates the efficacy...
The highly transmittable nature of SARS-CoV-2 has increased the necessity for novel strategies to safely decontaminate public areas. This study investigates the efficacy of a low irradiance 405-nm light environmental decontamination system for the inactivation of bacteriophage phi6 as a surrogate for SARS-CoV-2. Bacteriophage phi6 was exposed to increasing doses of low irradiance (~0.5 mW cm ) 405-nm light while suspended in SM buffer and artificial human saliva at low (~10 PFU mL ) and high (~10 PFU mL ) seeding densities, to determine system efficacy for SARS-CoV-2 inactivation and establish the influence of biologically relevant suspension media on viral susceptibility. Complete/near-complete (≥99.4%) inactivation was demonstrated in all cases, with significantly enhanced reductions observed in biologically relevant media (P < 0.05). Doses of 43.2 and 172.8 J cm were required to achieve ~3 log reductions at low density, and 97.2 and 259.2 J cm achieved ~6 log reductions at high density, in saliva and SM buffer, respectively: 2.6-4 times less dose was required when suspended in saliva compared to SM buffer. Comparative exposure to higher irradiance (~50 mW cm ) 405-nm light indicated that, on a per unit dose basis, 0.5 mW cm treatments were capable of achieving up to 5.8 greater log reductions with up to 28-fold greater germicidal efficiency than that of 50 mW cm treatments. These findings establish the efficacy of low irradiance 405-nm light systems for inactivation of a SARS-CoV-2 surrogate and demonstrate the significant enhancement in susceptibility when suspended in saliva, which is a major vector in COVID-19 transmission.
Topics: Humans; SARS-CoV-2; COVID-19; Decontamination
PubMed: 36872097
DOI: 10.1111/php.13798