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PloS One 2023This study aimed to synthesize fluoride-doped bioactive glass (F-BG) based thermo-sensitive injectable hydrogel for endodontic applications. The structural and phase...
This study aimed to synthesize fluoride-doped bioactive glass (F-BG) based thermo-sensitive injectable hydrogel for endodontic applications. The structural and phase analyses were done with Fourier Transform Infrared spectroscopy and X-ray Diffraction, respectively. The setting time of prepared injectable was investigated at 21°C (in the presence and absence of an ultrasonic scalar) and at 37°C. Flowability was tested according to ISO-6876:2012 specifications, whereas injectability was checked by extrusion method using 21-, 22-, and 23-gauge needles. The in vitro bio-adhesion and push-out bond strength were studied on days 7 and 90 and compared with the commercially available TotalFill®. The ion release profile was analyzed for up to 30 days with Inductively Coupled Plasma Optical Emission Spectroscopy. The fluoride release analysis was conducted periodically for up to 21 days in deionized water and artificial saliva using an ion-selective electrode. The final setting time at 21°C, 21°C+ultrasonic scalar, and 37°C were 38.66±3.21, 29.12±1.23, and 32±3.46 min, respectively. The flowability was 25±3.94 mm, and the injectability coefficient was ≥70.3 for 22, 21, and 57% in a 23-gauge needle. Fluoride release in deionized water was found to be significantly higher than in artificial saliva and increased with time. A significant difference in bond strength was found between days 7 and 90, where the strength was increased, and a new apatite layer was formed on the tooth surface. A rapid release of calcium, phosphate, and silicon ions was seen initially, whereby the continuous release of these ions was observed for up to 30 days. The prepared F-BG injectable hydrogel has shown promising results and has the potential to be used as an endodontic sealer.
Topics: Fluorides; Hydrogels; Saliva, Artificial; Dental Pulp Cavity; Glass; Water; Materials Testing
PubMed: 38011158
DOI: 10.1371/journal.pone.0294446 -
Micromachines Jul 2023The COVID-19 pandemic highlighted the importance of widespread testing for SARS-CoV-2, leading to the development of various new testing methods. However, traditional... (Review)
Review
The COVID-19 pandemic highlighted the importance of widespread testing for SARS-CoV-2, leading to the development of various new testing methods. However, traditional invasive sampling methods can be uncomfortable and even painful, creating barriers to testing accessibility. In this article, we explore how machine learning-enhanced biosensors can enable non-invasive sampling for SARS-CoV-2 testing, revolutionizing the way we detect and monitor the virus. By detecting and measuring specific biomarkers in body fluids or other samples, these biosensors can provide accurate and accessible testing options that do not require invasive procedures. We provide examples of how these biosensors can be used for non-invasive SARS-CoV-2 testing, such as saliva-based testing. We also discuss the potential impact of non-invasive testing on accessibility and accuracy of testing. Finally, we discuss potential limitations or biases associated with the machine learning algorithms used to improve the biosensors and explore future directions in the field of machine learning-enhanced biosensors for SARS-CoV-2 testing, considering their potential impact on global healthcare and disease control.
PubMed: 37630054
DOI: 10.3390/mi14081518 -
BMC Oral Health Sep 2023This present study assesses changes in the pH as well as the metal ions that fake braces release into artificial saliva (AS) using a pH meter and inductively coupled...
BACKGROUND
This present study assesses changes in the pH as well as the metal ions that fake braces release into artificial saliva (AS) using a pH meter and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively.
METHODS
Three sets of fake archwires (AWs) and brackets (Bs) as well as a set of controls were immersed in AS and placed in an incubator shaker at 50 rpm and 37°C. At Days 0, 1, 7, 14, 21, and 28, the pH of the AS medium was measured and 3.0 ml of AS was collected and stored at -20°C for elemental analysis.
RESULTS
Significant changes in pH were observed on Days 0, 1, 7, 14, 21, and 28 in the AS of the AW group. However, these changes were only observed in the B group on Days 0 and 7. The fake samples released a large quantity of sodium (Na), potassium (K), and calcium (Ca) ions, at concentrations exceeding 100 mg/L, post-28 days of immersion. The control and fake braces samples released other ions; such as lithium (Li), magnesium (Mg), barium (Ba), chromium (Cr), copper (Cu), lead (Pb), and aluminium (Al); at concentrations that did not exceed 10 mg/L.
CONCLUSIONS
The pH of the AS of all the samples increased post-incubation. Only 10 ions; namely, Na, Li, K, Mg, Ca, Ba, Cr, Cu, Pb, and Al; were detected in the AS.
Topics: Humans; Orthodontic Brackets; Saliva, Artificial; Lead; Aluminum; Chromium; Ions; Hydrogen-Ion Concentration
PubMed: 37717000
DOI: 10.1186/s12903-023-03339-7 -
European Journal of Pharmaceutical... Aug 2024The prevalence of xerostomia, the sensation of dry mouth, is estimated at 20 % in the general population and up to 50 % in older adults. Saliva plays different roles...
The prevalence of xerostomia, the sensation of dry mouth, is estimated at 20 % in the general population and up to 50 % in older adults. Saliva plays different roles during bolus formation: lubrication, mixing, coating, hydration, dissolution, and comminution of food particles. This study proposes and tests artificial saliva formulations mimicking human saliva rheological and sensory perceptions. Shear and extensional rheology were assessed to select the type of formulation closest to saliva rheological characteristics. After evaluating three alternative sources, an extract simulating saliva rheology was produced from flax seeds. Friction coefficient and rheological properties, such as flow curves, relaxation times, and Trouton ratios, were compared favorably with human saliva. The sensory evaluation demonstrated that flaxseed extracts induce perceived mouth hydration, slipperiness, and adhesion exceeding that of human saliva. The flaxseed extract proposed in this can i) be used to study in vitro food oral processing and ii) pave the way to novel natural salivary substitutes to alleviate the symptoms of xerostomia.
Topics: Rheology; Humans; Saliva; Flax; Saliva, Artificial; Plant Extracts; Female; Adult; Male; Xerostomia; Seeds; Young Adult
PubMed: 38763449
DOI: 10.1016/j.ejps.2024.106802 -
Cureus Jul 2023Previous literature data has extensively assessed the biocompatibility of various orthodontic adhesives and their components, where the results of most of the studies...
BACKGROUND
Previous literature data has extensively assessed the biocompatibility of various orthodontic adhesives and their components, where the results of most of the studies showed cytotoxic effects of different degrees owing to the unbound molecules released structurally from the cured components.
AIM
The present in-vitro study was aimed to assess the release of titanium dioxide nanoparticles in the artificial saliva from the orthodontic composites impregnated with titanium dioxide nanoparticles of 5% w/w (weight/weight) and 1% w/w used for metal brackets bonding.
METHODS
The study assessed 160 teeth extracted freshly during orthodontic treatment and divided into two groups of 80 samples, each that bonded to orthodontic brackets having 5% w/w and 1% w/w composites with titanium dioxide nanoparticles kept in the artificial saliva. Quantification was done for 5% w/w and 1% w/w composites having titanium nanoparticles with inductively coupled plasma mass spectroscopy at 24 hours, two, four, and six months.
RESULTS
It was seen that in teeth with 1% titanium dioxide, the greatest titanium release was seen at two months, with non-significant release after two months. In teeth with 5% w/w titanium dioxide nanoparticles showed significant titanium release all the time. A significantly greater titanium dioxide release on increasing concentration from 1% to 5% was seen for the 5% w/w group at all the assessment times.
CONCLUSION
The present study concludes that a higher release of titanium is seen in 5% w/w composite containing titanium dioxide nanoparticles, and the concentrations of 1% and 5% can be safely used and are considered to be within permissible limits.
PubMed: 37614253
DOI: 10.7759/cureus.42309 -
Journal of Dental Sciences Jul 2023The present study aimed to compare the force decay of invisible aligners for maxillary anterior teeth with 0.1 mm (D), 0.2 mm (D), and 0.3 mm (D) labial movement...
BACKGROUND/PURPOSE
The present study aimed to compare the force decay of invisible aligners for maxillary anterior teeth with 0.1 mm (D), 0.2 mm (D), and 0.3 mm (D) labial movement within a simulated oral environment over 7 days.
MATERIALS AND METHODS
The prepared invisible aligners were immersed in saliva (S) and subjected to applied force (F) for 7 days. The aligners were set and placed on the maxillary right central incisor with 0.1 mm (D), 0.2 mm (D), and 0.3 mm (D) labial movement. Thin-film pressure sensors were used to measure the aligner force changes. The data were collected and analyzed by statistical methods.
RESULTS
Significant differences were observed in the initial and first-day force between the D and D groups under simulated oral environment force (SF) ( < 0.05). There was a significant difference in force decay between Day 1 and Day 7 for all groups ( < 0.05). The SFD group showed a significant decrease in force on Day 5 ( < 0.05), while the SFD and SFD groups showed significant force decay on Day 4 ( < 0.05). The force decay ratio on Day 7 was higher in the SFD group than in the SFD and SFD groups, but no significant difference was observed.
CONCLUSION
Larger labial movement of the aligners resulted in higher force decay under artificial saliva environments, and the force decay of invisible aligners was increased by immersion time in artificial saliva.
PubMed: 37404637
DOI: 10.1016/j.jds.2023.04.017 -
Polymers Jul 2023One of the crucial factors influencing the longevity of anterior aesthetic dental restorations is the colour stability of resin composites. Bleaching and whitening have...
BACKGROUND
One of the crucial factors influencing the longevity of anterior aesthetic dental restorations is the colour stability of resin composites. Bleaching and whitening have become popular methods for enhancing dental aesthetics. Home whitening techniques, such as special pens, are widely available commercially. This in vitro study aimed to determine the efficiency of a whitening pen in removing tea stains from resin composite by measuring colour differences (ΔE). Additionally, the study aimed to evaluate the variations in colour parameters measured by extra-oral and intra-oral spectrophotometers.
METHODS
A total of 45 disc-shaped resin composite specimens were randomly divided into three groups; Group 1: stored in artificial saliva (control), Group 2: stored in artificial saliva followed by a whitening pen application, and Group 3: stored in tea followed by a whitening pen application. Colour measurements were taken three times for each specimen using two spectrophotometers (extra-oral and intra-oral devices); T1: before storage (baseline), T2: after storage in artificial saliva or tea for 6 days; and T3: after one week of whitening pen application in groups 2 and 3. The data were statistically analyzed using one-way ANOVA followed by the Tukey post hoc test ( ≤ 0.05). The independent sample -test was also employed. The equation of CIEDE2000 (ΔE) was used to calculate the colour difference between the dry, as-prepared specimens (baseline), and those after storage or bleaching. The colour changes exceeding the acceptability threshold (∆E = 1.8) were considered unacceptable.
RESULTS
After whitening, the colour of the specimens stored in brewed tea (Group 3) remained unacceptable, as indicated by both the extra-oral and intra-oral spectrophotometers (ΔE = 4 and 2.9, respectively). Groups 1 and 2 exhibited lower ΔE values than Group 3 ( = 0.01 *). No significant difference was observed between Group 1 (stored in artificial saliva) and Group 2 (stored in artificial saliva and then bleached) ( = 0.3). Significant differences were consistently observed between the data obtained from the extra-oral spectrophotometer and the intra-oral one.
CONCLUSIONS
The whitening pen proved ineffective in removing tea stains from resin composites. Although significant differences were found between the values obtained by the two spectrophotometers (extra-oral and intra-oral), both devices confirmed the unacceptable colour of the tea-stained resin composites after whitening.
PubMed: 37514457
DOI: 10.3390/polym15143068 -
Clinical Oral Investigations Oct 2023To investigate the antibacterial and enamel remineralization performances as well as physicochemical properties and biocompatibility of a fluoride-coated clear aligner...
OBJECTIVE
To investigate the antibacterial and enamel remineralization performances as well as physicochemical properties and biocompatibility of a fluoride-coated clear aligner plastic (FCAP).
MATERIALS AND METHODS
FCAP and normal clear aligner plastic (CAP) was bought from the manufacturer (Angelalign Technology Inc, China). The FCAP was observed under scanning electron microscopy. Its element composition, resistance to separation, contact angle, and protein adhesion performance were characterized. Colony-forming unit (CFU) count and 3-(4,5)-dimethylthiazol(-z-y1)-3,5-diphenyltetrazolium bromide (MTT) assay were used to evaluate the antibacterial ability of Streptococcus mutans. Fluoride release-recharge patterns were obtained. Apatite formation was evaluated after immersing FCAP in artificial saliva. Enamel remineralization capability was evaluated in the demineralization model (immersing samples in demineralization solution for 36 h) and pH cycling model (immersing samples in demineralization solution and remineralization solution in turns for 14 days). Cell Counting Kit-8 (CCK-8) and live/dead cell staining kits were used for cytotoxicity assay.
RESULTS
The FCAP showed uniformly distributed fluoride and did not compromise protein adhesion performance. CFU count (5.47 ± 0.55 for CAP, 3.63 ± 0.38 for FCAP) and MTT assay (0.41 ± 0.025 for CAP, 0.28 ± 0.038) indicated that the FCAP had stronger antibacterial activity compared with normal CAP (P < 0.05 for both evaluations). The FCAP could release fluoride continuously for 14 days and could be recharged after immersing in NaF solution. The FCAP could induce the formation of hydroxyapatite in artificial saliva and could reduce the microhardness decrease, color change, and mineral loss of enamels in both two models (P < 0.05 for all evaluations). CCK-8 and live/dead cell staining analyses showed that the coating did not compromise the biocompatibility of the clear aligner (P > 0.05 for CCK-8 evaluation).
CONCLUSIONS
The FCAP had antibacterial, fluoride recharge, and enamel remineralization abilities while it did not compromise physicochemical properties and biocompatibility.
CLINICAL RELEVANCE
The FCAP has the potential to prevent enamel demineralization during clear aligner treatment.
Topics: Humans; Fluorides; Tooth Demineralization; Saliva, Artificial; Tooth Remineralization; Hydrogen-Ion Concentration; Dental Enamel; Anti-Bacterial Agents; Orthodontic Appliances, Removable; Dental Caries; Sodium Fluoride; Cariostatic Agents
PubMed: 37620439
DOI: 10.1007/s00784-023-05216-7 -
Materials (Basel, Switzerland) Mar 2024The main aim of this study was to assess the impact of the environment on the mechanical and tribological properties of glass-carbomer cements used in dentistry. The...
The main aim of this study was to assess the impact of the environment on the mechanical and tribological properties of glass-carbomer cements used in dentistry. The properties of the Glass Cements Polyalkene (GCP) Glass Fill material, belonging to glass-polyalkene cements, were tested after placing it in various environments: air, distilled water, artificial saliva simulating a neutral environment (pH = 7), and simulating inflammation (pH = 4). The research material included four samples and a two-year reference material. The analysis of volumetric consumption and the assessment of the impact of solubility on the stability of glass-carbomer cements were carried out using tribological measurements and Vickers hardness measurements. In addition, microstructural characterization of the materials was performed using scanning electron microscopy (SEM). It was observed that the lowest wear (0.04%), the most stable microstructure, and the lowest average hardness (21.52 HV 0.1) were exhibited by the material stored in artificial saliva simulating a neutral environment (pH = 7). The least stable microstructure and statistically the highest hardness (77.3 HV 0.1) was observed in the test sample, which was stored in air for two years and then in distilled water. The highest consumption (0.11%) was recorded in the case of cement placed in artificial saliva simulating inflammation (pH = 4). The results obtained in this study indicate specific trends in the influence of the environment in which the tested cement is located, such as air, distilled water, air/distilled water, artificial saliva simulating a neutral environment, and simulating inflammation, on its structure, hardness, and wear.
PubMed: 38473657
DOI: 10.3390/ma17051186 -
BMC Oral Health Dec 2023To compare force degradation of elastomeric chains and NiTi coil springs in vivo and in vitro, and evaluate the effects of pre-stretched and reused elastomeric chains in...
OBJECTIVE
To compare force degradation of elastomeric chains and NiTi coil springs in vivo and in vitro, and evaluate the effects of pre-stretched and reused elastomeric chains in the oral cavity during the time.
METHODS
In the in vitro groups, 4-unit elastomeric chains and NiTi coil springs with an initial force of 200 g were placed in dry air and artificial saliva. The volunteers wore clear retainers which were used to hold the sample of 4-unit chains, pre-stretched 4-unit chains, and NiTi coil springs with the initial force of 200 g in the in vivo groups. After the first 4 weeks, 4-unit specimens were stretched to 200 g again for another 4 weeks in vivo. The force value and the percentage of force degradation were recorded at each measurement time interval in the in vivo and in vitro groups.
RESULTS
The force degradation of elastomeric chains was greatest within the initial 4 hours, followed by a more stable phase after 1 week. The average force degradation of 4-unit elastomeric chains after 4 weeks was in vivo (64.8%) > artificial saliva (55.0%) > dry air (46.42%) (P < 0.05). The force degradation of NiTi coil springs in vivo (15.36%) or in artificial saliva (15.8%) was greater than in dry air (7.6%) (P < 0.05). NiTi coil springs presented a gentler force decay than elastomeric chains during the period (P < 0.05). In vivo, the force degradation of pre-stretched and reused elastomeric chains decreased less than the regular style(P < 0.05).
CONCLUSION
The force degradation of the elastomeric chains and NiTi coil springs varied in different environments. NiTi coil springs presented a gentler force decay than elastomeric chains during the period. Orthodontists should consider the force degradation characteristics of orthodontic accessories in clinical practice.
Topics: Humans; Saliva, Artificial; Nickel; Titanium; Elasticity; Orthodontic Appliances; Materials Testing; Orthodontic Wires
PubMed: 38097980
DOI: 10.1186/s12903-023-03737-x