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Purpose: To evaluate the effect of three different curing protocols based on different ratios of self-curing and light-curing periods on the bond strength and nanoleakage of fiber posts luted with dual-curing selfadhesive cements. Materials and Methods: A total of 48 single-root teeth were endodontically treated and obturated, and an 8-mm post space was prepared with dedicated drills. Specimens were randomly divided into two groups according to the self-adhesive cement employed: group 1 (G1) = PANAVIA SA Plus (Kuraray Noritake), and group 2 (G2) = Bifix SE (VOCO). The specimens were further divided into three subgroups (n = 8 each) according to the light-curing protocol applied: no light-curing (SG1), 20 seconds of light-curing 20 seconds after cement injection (SG2), and 20 seconds of light-curing 120 seconds after cement injection (SG3). Slices of 1-mm thickness were prepared for the pushout test and nanoleakage analyses of the coronal and apical regions after 24 hours of storage in artificial saliva. Results were statistically analyzed with threeway ANOVA and Tukey post hoc tests. Statistical significance was set for P < .05. Results: Three-way ANOVA analysis showed that the factors of cement (P = .02) and curing protocol (P < .001) had a significant influence on bond strength. Tukey post hoc test reported that light-curing 120 seconds after injection showed higher bond strength compared to both no light-curing and photoactivation after 20 seconds. Conclusion: To achieve the highest bond strength with self-adhesive cements, photoactivation with a 120-second delay after mixing is required. There is no difference between light-curing immediately and light-curing 20 seconds after mixing. [ABSTRACT FROM AUTHOR]

Due to the increasing risk of obesity and cardiovascular diseases caused by high-fat diets, low-fat foods have become a priority demand for consumers' health. However, the smoothness perception and scientific assessment methods of the existing low-fat foods should be improved. In this study, three food emulsions were prepared, and their lubrication characteristics, sensory evaluation of smoothness, and electroencephalogram (EEG) signals were assessed to preliminarily investigate the effects of food emulsion components on their above characteristics. The results showed that fat substitute (FSU) and fat could significantly reduce coefficient of friction (CoF) of the food emulsions, with average CoF reduced by 28% and 63% compared to the original food emulsions. In addition, fat-enriched food emulsions continued to exhibit excellent lubrication characteristics after adding artificial saliva, with an average CoF reduced by 31.1% compared to that of the food emulsions without artificial saliva. Both FSU and fat improved the smoothness of food emulsions, and the lubricating properties of fat were more pronounced, with fat-enriched food emulsion which could provide a substantial improvement in smoothness compared to the fat-free food emulsion. Comparison of subjects' EEG signals revealed that food emulsion with lower CoF and higher smoothness triggered higher P3 amplitudes and longer latencies. These findings provide better insights into the scientific evaluation of food texture and the development of low-fat foods. [ABSTRACT FROM AUTHOR]

The availability of well-established analytical methods is crucial to cope with the fast-ongoing research for the development of new drug delivery formulations. In this work, a rapid highly green chromatographic method was developed for the simultaneous determination of nicotine (NIC) and caffeine (CAF) to be applied for an in-vitro release study from a newly prepared quick mist mouth spray co-formula (QMS), as a complementary synergistic fast-onset relief of cravings during smoking cessation. The chromatographic resolution was accomplished on a cyano column using isocratically delivered (1.0 mL/ min) glycerol: orthophosphoric acid (OPA) (0.2 M) adjusted to pH 3.0 using 0.05 M triethylamine (5:95, v/v) and UV detection at 260 nm. Well resolved peaks of NIC and CAF were eluted at 2.1 and 3.9 min (Rs = 5.64), with linear responses between 0.1 and 20.0 µg/mL and 0.2–40.0 µg/mL, and detection limits of 0.03 and 0.07 µg/mL for NIC and CAF, respectively. The developed method showed good analytical performance (accuracy, precision, robustness, and selectivity) as well as superiority in practicality and ecological profile compared to reported methods applying GAPI, analytical eco-scale, AGREE, BAGI, and whiteness metric tool. The developed method was successfully applied for NIC and CAF determination in their pharmaceutical preparations, and artificial saliva with no significant differences from reported method results (F-test and t-test). Moreover, an in-vitro release study of NIC and CAF from QMS was performed employing the developed method that revealed diffusion-controlled release, compared to mixed diffusion/ polymer chain relaxation for marketed single component formulation, showing the superiority of QMS in reducing drug level fluctuations of NIC and CAF and improving their bioavailability. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Materials and Methods Results Conclusions Clinical Relevance To evaluate the effects of dentifrices containing sodium fluoride (NaF) combined with NovaMin (Sensodyne Repair & Protect—SRP), NaF combined with stannous fluoride (SnF2, Oral‐B Pro‐Gengiva—OBP), and amine fluoride (AmF, Colgate Elmex—ELM) on enamel subjected to simulated erosive cycling.Bovine enamel‐dentin discs (n = 10/group) were subjected to erosive cycling with orange juice (pH = 3.29, 5 min, 3x/day), artificial saliva (SA–2 h, 3x/day and overnight) and treated with dentifrice (2 min, 2x/day) or without treatment (CONT). Surface microhardness (SMH) was evaluated at baseline (T0), on the first (T1) and fifth (T5) days. SMH loss (%SHL) was calculated. Surface roughness (Ra, μm) was determined at T0 and T5. Morphology and mineral content were evaluated under scanning electron microscopy and energy‐dispersive x‐ray spectroscopy. Data were analyzed using ANOVA/Tukey or Bonferroni (α = 5%).No differences in %SHL were detected among groups at T1. At T5, OBP promoted %SHL, Ra, and ΔRa significantly lower than all the other groups (p < 0.05). All groups exhibited morphological changes in topography and similar Ca/P means before and after treatments.Dentifrice containing SnF2 minimized the negative effects on the SMH and Ra caused by exposure to orange juice after 5 days of simulated cycling.Patients who are more exposed to risk factors for dental erosion could benefit from the use of dentifrice containing SnF2. [ABSTRACT FROM AUTHOR]

A growing interest in dental practice in intranasal anesthesia using tetracaine and oxymetazoline dictates the need for their simultaneous determination in combination drugs and human saliva. Potentiometric multisensory systems based on perfluorosulfonic acid membranes, including polyaniline‐modified ones, were developed for these purposes. A change in the distribution of the sensor sensitivity to the related analytes was achieved by variation of the conditions for concentration polarization at the membrane interface with a studied solution due to a change in the intrapore volume, nature, and availability of the sorption centers, as well as the hydrophilicity of the membrane surface that were specified by the conditions for their synthesis and subsequent hydrothermal treatment. Reversibility of the analyte sorption using the chosen conditions for regeneration provided long‐term stable work of both the sensors and the calibration equations established by multivariate linear regression. The membrane modification promoted their resistance to fouling. The relative errors of the simultaneous tetracaine and oxymetazoline determination in the combination drug solutions were no greater than 7% and 11%, while in the artificial saliva solutions, they were 15% and 17%, respectively, when an array of the cross‐sensitive sensors based on the composite membranes prepared by different methods was used. The analysis errors were reduced to 3%–6% when analyzing the drug and to 0.2%–6% when analyzing the artificial saliva if an array was organized with the sensors based on the membrane with the dopant and the membrane without it, due to the decreasing correlation between their responses. Potentiometric multisensory systems based on perfluorosulfonic acid membranes, including polyaniline‐modified ones, were developed for the simultaneous determination of tetracaine and oxymetazoline in combination drugs and human saliva. Reversibility of the analyte sorption during regeneration provided long‐term stable work of the sensors and calibration equations established by multivariate linear regression. The analysis errors were 0.2%–6% for the sensor array based on the membrane with polyaniline and the one without it, due to the low correlation between the responses. [ABSTRACT FROM AUTHOR]

The aim of this study was to design and assess composite resin composition for patient-specific esthetic color-graded temporary veneer. Various compositions of composite structures (assorted by Ba 2 SiO 4 filler, TiO 2 pigment, and photoinitiator) were prepared via additive manufacturing with 3 s UV exposure (405 nm, 10 W/cm2) per 50 µm thick layer followed by 20 min post-curing treatment after fabrication. The effect of each component on the generated color shades was observed and compared to the commonly used VITA shade guide. The coloration was explored by staining aging treatment under dry, wet, artificial saliva environments, coffee, and cola. The mechanical properties were also evaluated. Color measurement and comparison were done using a colorimeter (lightness (L*), green-red color (a*), and blue-yellow color (b*)), and the changes were calculated by CIEDE2000 (ΔE 00), translucency parameter (TP) and whiteness index (WI D). The composition color analysis results were then applied to produce a color-graded temporary veneer for mimicking a natural look. Mechanically, all composition result in adequate bending strength with maximum achievable strength of 111.64 MPa. At the same time, the composite color was affected by each constituent differently. The L* value, which indicates the color lightness of the composite, was considerably tuned by the TiO 2 pigment, whereas Ba 2 SiO 4 filler only triggered minor changes. Photoinitiator concentration significantly affected the yellowness, indicated by the increased b* value. Similar tendency also observed toward the calculated TP and WI D as well. Based on these evaluations, color-graded temporary veneer successfully generated, matching the VITA A3, A2, and B1 shades gradation. However, the stability of the composite color decreased at high amounts of Ba 2 SiO 4 and photoinitiator. The study presents a composition guide for fabricating temporary patient-specific color-graded veneer. It provides insights on the effect of the constituent material on dental esthetics. [Display omitted] • Practical use of functionally graded AM (FGAM) for esthetic composites veneer. • Customized composites (varying filler, pigment, photoinitiator) for dental implant • Improved esthetics, mimicking natural teeth, achieved via composition control • High strength and stain resistance composites comparable to conventional implants [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the shear bond strength (SBS) of resin composite to dentin contaminated with artificial saliva (AS) containing mucin and amylase using an experimental method controlling the volume of saliva and adhesive in a defined surface area. Methods: Flat bonding surfaces were prepared on extracted human molars (320 grit surface). Using adhesive tape, a 4.5 mm bonding window was prepared on the dentin surfaces. Groups (n= 12) were prepared using the etch & rinse (ER) or self-etch (SE) modes for Adhese Universal (ADH), Scotchbond Universal Plus (SBU), and Prime & Bond active (PBA) dental adhesives (DA). For the control (C) groups, the adhesives were applied per the manufacturers' instructions with 2.0 μl or 3.0 μl of the adhesive. For the saliva-contaminated groups, 1.0 μl of artificial saliva with mucin was applied in the bonding window either dried or allowed to remain wet before the application of either 2.0 μl or 3.0 μl of the adhesive. After the adhesive film was air dried and light cured using an Ultradent bonding fixture, Spectrum TPH3 was bonded to the prepared surfaces. After water storage for 24 hours at 37oC, the specimens were debonded and shear bond strength (SBS) was calculated (MPa). A Kruskal-Wallis test with Bonferroni correction was used to determine group differences (P< 0.05). Scanning electron microscopy (SEM) was performed to visualize the interfacial surfaces prepared using an ion-etching technique. Results: Mean SBS for the three adhesives were similar in both ER and SE modes to Uncontaminated dentin surfaces for all the control groups. For dentin contaminated with dried or wet saliva, both the surface condition and the adhesive system were significant factors at a confidence level of 95%. For the dried saliva test groups, ADH and PBA with 3.0 μl of adhesive generated similar SBS values to controls while SBU generated lower values. Lower values were generated when using 2.0 μl of adhesive for the three adhesives in SE and ER modes except for PBA in the ER mode. Using wet saliva and 3.0 μl of adhesive ADH and SBU generated lower SBS values while PBA generated similar values to controls. Under SEM, morphology at the adhesive dentin interfaces was similar among the adhesives to uncontaminated dentin but notable differences were observed for SBU and ADH for both wet and dried saliva-contaminated surfaces. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study is to evaluate the discolouration resistance of attachments made of composites having different physical properties, filler ratios and viscosity through the simulated environment and conditions. Materials and Methods: Seventy‐two extracted human teeth were aligned to simulate upper and lower dental arches. The attachments were prepared according to the guides determined by ClearCorrect. Three different composite groups were used for attachments preparation: Aligner Connect, G‐Aenial Universal Injectable, and Tetric Prime and Tetric Evoflow combination. Dental models and aligners were kept in artificial saliva throughout the experiment of 96 weeks. The aligners were also subjected to 2308 thermal cycles and insertion and removing procedures 840 times for each period of 12 weeks. Afterwards, the models were kept in coffee and red wine solutions. Colour measurements were made with Vita Easy Shade 4.0 at 12th, 24th, 48th and 96th simulated weeks. Results: No significant difference in discolouration was observed during thermal cycle application of 12th and 24th week experimental periods. In the later periods, discolouration was observed in the composite materials, and G‐Aenial Universal Injectable was less coloured than the other samples. The composite samples were more coloured in proportion to their residence time. The G‐Aenial Universal Injectable was more affected by wine solution, and Tetric Prime and Tetric Evoflow combination were more affected by coffee solution. Conclusions: Viscosity, resin matrix content and nature of inorganic filler particles of the composite materials significantly affect the colour changing properties of them due to the long‐term ageing and exposure to colouring agents. [ABSTRACT FROM AUTHOR]

Although Streptococcus pyogenes and Candida albicans may colonize tonsillar tissues, the interaction between them in mixed biofilms has been poorly explored. This study established an interkingdom biofilm model of S. pyogenes and C. albicans and verified the dose-response validation of antimicrobials. Biofilms were formed on microplates, in the presence or absence of a conditioning layer of human saliva, using Brain Heart Infusion (BHI) broth or artificial saliva (AS) as a culture medium, and with variations in the microorganism inoculation sequence. Biofilms grown in AS showed higher mass than those grown in BHI broth, and an opposite trend was observed for metabolism. The number of S. pyogenes colonies was lower in AS. Amoxicillin and nystatin showed dose-dependent effects. The inoculation of the two species at the same time, without prior exposure to saliva, and using BHI broth would be the model of choice for future studies assessing the effects of antimicrobials on dual S. pyogenes/C. albicans biofilms. [ABSTRACT FROM AUTHOR]

Restoring the structures and functions of tissues along with organs in human bodies is a topic gathering attention nowadays. These issues are widely discussed in the context of regenerative medicine. Excipients/delivery systems play a key role in this topic, guaranteeing a positive impact on the effectiveness of the drugs or therapeutic substances supplied. Advances in materials engineering, particularly in the development of hydrogel biomaterials, have influenced the idea of creating an innovative material that could serve as a carrier for active substances while ensuring biocompatibility and meeting all the stringent requirements imposed on medical materials. This work presents the preparation of a natural polymeric material based on pullulan modified with silymarin, which belongs to the group of flavonoids and derives from a plant called Silybum marianum. Under UV light, matrices with a previously prepared composition were crosslinked. Before proceeding to the next stage of the research, the purity of the composition of the matrices was checked using Fourier-transform infrared (FT-IR) spectroscopy. Incubation tests lasting 19 days were carried out using incubation fluids such as simulated body fluid (SBF), Ringer's solution, and artificial saliva. Changes in pH, electrolytic conductivity, and weight were observed and then used to determine the sorption capacity. During incubation, SBF proved to be the most stable fluid, with a pH level of 7.6–7.8. Sorption tests showed a high sorption capacity of samples incubated in both Ringer's solution and artificial saliva (approximately 350%) and SBF (approximately 300%). After incubation, the surface morphology was analyzed using an optical microscope for samples demonstrating the greatest changes over time. The active substance, silymarin, was released using a water bath, and then the antioxidant capacity was determined using the Folin–Ciocâlteu test. The tests carried out proved that the material produced is active and harmless, which was shown by the incubation analysis. The continuous release of the active ingredient increases the biological value of the biomaterial. The material requires further research, including a more detailed assessment of its balance; however, it demonstrates promising potential for further experiments. [ABSTRACT FROM AUTHOR]

Background: Decreased salivary flow can make the patients uncomfortable with their complete dentures and affects the retention of the dentures. Milling and 3D printing have become an alternative to conventional denture construction techniques. The goal of this study was to evaluate the effect of conventional and digital techniques of the complete denture construction on the denture surface wettability with distilled water and saliva substitute before and after thermocycling. Methods: A total of 30 specimens were utilized in the present study. Specimens were divided according to the construction techniques into 3 groups (n = 10 each). Group I: Heat-polymerized polymethylmethacrylate (PMMA) group, group II: Milled group, and group III: 3-dimensional (3D)-printed group. All the specimens were subjected to 2000 cycles of thermal aging in a thermocycler. The wettability of all specimens to water and saliva substitute was measured via a contact angle goniometer (Olympus TGHM, Rame-hart Inc, USA) before and after thermocycling. Descriptive statistical analysis, plots, and the Shapiro-Wilk test were used to verify normality for each variable. One-way ANOVA was used to compare the 3 study groups, while paired samples t-test was used to compare the differences within each group (P <.05). Results: The smallest contact angle of drop of water to the denture base specimens before and after thermocycling were recorded in the milled group (53.0 ± 4.77 and 50.27 ± 2.30, respectively), followed by the heat polymerized PMMA group (85.65 ± 4.71 and 65.06 ± 2.27, respectively), and the 3D-printed group (91.34 ± 6.74 and 90.86 ± 8.57, respectively). While the smallest contact angle of drop of saliva substitute to denture base specimens was recorded in the milled group (56.82 ± 2.29 and 34.85 ± 7.51, respectively), followed by the 3D-printed group (72.87 ± 4.83 and 58.14 ± 9.58, respectively) and the heat polymerized PMMA group (83.62 ± 4.12 and 67.82 ± 4.93, respectively). There was statistically significant difference between the groups (P <.05). A significant decline in the average contact angle of drop of saliva has been reported in all groups after thermocycling. The contact angle values differed significantly between saliva substitute and distilled water in both 3D-printed and milled groups after thermocycling (P <.001). Conclusions: The milled denture base material presented the best wettability to water and saliva substitute than the 3D-printed and the heat-polymerized PMMA materials. Saliva substitutes improve the wetting ability of denture base materials manufactured by CAD/CAM compared with water. [ABSTRACT FROM AUTHOR]

Background: White spot lesions are a widespread undesirable effect, especially prevalent during fixed orthodontic treatments. The study compared the in vitro enamel remineralization potential of undemineralized dentin matrix (UDD) versus chicken eggshell powder (CESP) for artificially induced enamel lesions. Methods: 100 caries-free and sound maxillary premolars were randomly divided into four groups each contain 25 teeth: Group I (Baseline): No treatment was done to the enamel surface. Group II (Negative control): The enamel surface of the teeth underwent demineralization using demineralizing solution to create artificial carious lesions then kept in artificial saliva. Group III (CESP treated): After demineralizing the tooth surface, the teeth have been suspended in the CESP remineralizing solution. Group IV (UDD treated): After enamel demineralization, the teeth were suspended in UDD remineralizing solution. The remineralization potential was assessed by Vickers microhardness testing, scanning electron microscopic examination (SEM), and energy dispersive X-ray (EDX). Results: The current study demonstrated an increase in the mean microhardness of CESP and UDD-treated groups; however, It was nearer to the baseline level in the UDD group. SEM imaging revealed greater enamel remineralization in the UDD group compared to the remaining groups. The UDD group disclosed complete coverage for the prismatic enamel compared to the CESP group, which revealed a partially remineralized enamel surface. Interestingly, the Ca/P ratio increased significantly in the CESP group compared to the negative control group. In contrast, a higher significant increase in the mean Ca/P ratios was recorded in the UDD group compared to the test groups. Conclusion: biomimetic UDD and CESP powder should be utilized to treat enamel early carious lesions. However, UDD demonstrated the most significant remineralization potential. [ABSTRACT FROM AUTHOR]

Needle-free buccal anesthesia improves dental treatment outcomes for both patients and dentists. In this study, we report on an assessment of the enhancement effects of α-bisabolol on the in vitro transmucosal permeation of prilocaine hydrochloride (PCl) and lidocaine hydrochloride (LCl) from needleless buccal films. We also evaluated the mechanical properties of the film, which consisted of Methocel™ K100 LV as the film-forming polymer (3% m·m−1), PEG 400 as a cosolvent (15% m·m−1 based on drug loading), α-bisabolol (15 and 30% m·m−1 based on drug loading), and the drugs combined at a 1:1 ratio (15 mg·unit−1). The porcine esophageal epithelium was used as a membrane barrier, and artificial saliva was the release medium. After a 1 h experiment at 25 ± 2 °C, α-bisabolol significantly decreased, rather than enhanced, the permeation fluxes (five-fold), permeability coefficients (seven-fold), and retentions (two-fold) of both PCl and LCl through the epithelium, regardless of the concentration. Moreover, the resistance and flexibility of the films markedly decreased compared to those without α-bisabolol. Therefore, under the experimental conditions, using α-bisabolol as a buccal permeation enhancer for the hydrophilic local anesthetics PCl and LCl from buccal films is not feasible. [ABSTRACT FROM AUTHOR]

Although titanium and its alloys are widely used as dental implants, they cannot induce the formation of new bone around the implant, which is a basis for the functional integrity and long-term stability of implants. This study focused on the functionalization of the titanium/titanium oxide surface as the gold standard for dental implants, with electrospun composite fibers consisting of polyvinylpyrrolidone and Ca2+ ions. Polymer fibers as carriers of Ca2+ ions should gradually dissolve, releasing Ca2+ ions into the environment of the implant when it is immersed in a model electrolyte of artificial saliva. Scanning electron microscopy, energy dispersive X-ray spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy confirmed the successful formation of a porous network of composite fibers on the titanium/titanium oxide surface. The mechanism of the formation of the composite fibers was investigated in detail by quantum chemical calculations at the density functional theory level based on the simulation of possible molecular interactions between Ca2+ ions, polymer fibers and titanium substrate. During the 7-day immersion of the functionalized titanium in artificial saliva, the processes on the titanium/titanium oxide/composite fibers/artificial saliva interface were monitored by electrochemical impedance spectroscopy. It can be concluded from all the results that the composite fibers formed on titanium have application potential for the development of osteoinductive and thus more biocompatible dental implants. [ABSTRACT FROM AUTHOR]

Baghdadite (Ca 3 ZrSi 2 O 9) cements of various composition have been investigated in this study regarding an application as endodontic filling materials. Cements were either obtained by mixing mechanically activated baghdadite powder with water (maBag) or by subsequently substituting the ß-tricalcium phosphate (ß-TCP) component in a brushite forming calcium phosphate cement. The cements were analyzed for their mechanical performance, injectability, radiopacity, phase composition and antimicrobial properties. The cements demonstrated sufficient mechanical performance with a compressive strength of ∼1 MPa (maBag) and 2.3 – 17.4 MPa (substituted calcium phosphate cement), good injectability > 80 % depending on the powder to liquid ratio and an intrinsic radiopacity of 1.13 – 2.05 mm aluminum equivalent. Immersion in artificial saliva proved their bioactivity by the formation of calcium phosphate and calcium silicate precipitates on the cement surface. The bacterial activity of Staphylococcus aureus cultured on the surface of the cements was found to be similar compared to clinical standard ProRoot MTA cement or even reduced by a factor of 3 for Streptococcus mutans. In combination with their antibacterial properties, baghdadite cements are thought to have the potential to fulfil the clinical requirements for endodontic filling materials. • Different baghdadite (Ca 3 ZrSi 2 O 9) cements have been synthesized and investigated regarding their application as endodontic materials. • The cements demonstrated sufficient mechanical performance, good injectability and an intrinsic radiopacity. • Bacterial activity of Staphylococcus aureus cultured on the baghdadite cements was similar to ProRoot MTA. • Bacterial activity of Streptococcus mutans cultured on baghdadite cements was three times lower than on ProRoot MTA. • maBag cement seems to be the more promising candidate due the high alkaline pH. [ABSTRACT FROM AUTHOR]

Objective: this study aimed to digitally compare wear behavior and retention between PEEK and nylon retentive inserts used in locator-retained, mandibular implant overdentures when attachment design and size were standardized. Materials and methods: A total of sixty-four inserts (32 PEEK and 32 nylon inserts); were picked-up in implant overdentures. Overdentures of both groups were submerged in artificial saliva and mounted to chewing simulator. After 480,000 chewing cycles (equivalent to 2 years of clinical use) all inserts were scanned by scanning electron microscope (SEM), then all acquired images were digitally analyzed by software to detect and compare quantitative and qualitative changes of inserts in both groups. On the other hand, retention of both groups was measured by universal testing machine and the collected data was statistically analyzed using one-way Analysis of Variance (ANOVA) test with significance level set at P ≤ 0.05. Results: PEEK inserts showed significantly higher mean retentive values compared to the nylon inserts in the control group. Also, PEEK retentive inserts exhibited statistically lower mean wear values than the control group P ≥ 0.000. Qualitative investigation revealed significant and more pronounced changes in the surface roughness of nylon inserts compared to PEEK ones. Conclusions: Regarding retention, wear behavior and dimension stability, PEEK can be recommended as retentive insert material in cases of locator-retained mandibular implant overdentures. Clinical relevance: PEEK inserts offer enhanced retention, reduced wear, and greater dimensional stability over two years time interval. Clinically, this reduces prosthodontic maintenance and adjustments, improving patient satisfaction and long-term prosthetic success. [ABSTRACT FROM AUTHOR]

Dental implants are intended to function as a durable method for replacing missing teeth. A biocompatible dental alloy is used to achieve integration with the jawbone through Osseointegration. This creates a strong base for the implant, allowing it to withstand the mechanical forces generated during biting and chewing. Dental alloys are commonly subjected to various mouth conditions known for their intricate corrosion potential. Corrosion can weaken the structural integrity of the implant, causing issues such as implant loosening, micro-motion at the implant-bone contact, implant fracture, allergic reactions, toxicity, and possible disruption of the Osseo integration process. To improve the alloy's corrosion resistance and biocompatibility, its surface can be altered using nanocomposite materials. The materials provide a protective coating to the alloy, creating a physical barrier that effectively prevents corrosive substances from reaching the underlying bulk material. This study involves modifying the surface of the dental alloy Ti–13Nb–13Zr with Fluroapatite (FAP)/Silicon dioxide (SiO 2) modified zirconia (ZrO 2) nano composites. The altered surfaces are then studied in simulated body fluid and artificial saliva solutions using in vitro methods. The FAP/SiO 2 modified ZrO 2 nanocomposites is applied onto a Ti–13Nb–13Zr alloy utilizing Electrophoretic deposition and Dip coating techniques. The coated samples were analysis utilizing FTIR, XRD, and SEM with EDS. Corrosion analysis was carried out on coated and uncoated samples using Electrochemical methods in simulated body fluid and artificial saliva solution. The biocompatibility is assessed using MTT assay, contact angle, and immersion testing in both SBF and Artificial saliva. EIS and corrosion study results show that FAP/SiO 2 modified ZrO 2 nanocomposites coated Ti13Nb13Zr alloy has high polarization resistance, low corrosion rate, and good charge transfer resistance, indicating excellent corrosion resistance. The contact angle study showed that the surface-modified Ti13Nb13Zr alloy is superhydrophilic, increasing implant surface osseointegration. Cell viability measurements reveal good cell growth, while immersion investigations show calcification, leading to enhanced osseointegration between the implant and its surrounding tissues. hence, it is an excellent material for dental implants application. [ABSTRACT FROM AUTHOR]

Objectives: Using toothpaste with activated carbon might increase the decay of orthodontic elastomeric chains' (ECs) tensile strength, thereby compromising orthodontic treatment. Therefore, this study aimed to evaluate the influence of activated charcoal toothpaste on orthodontic ECs. Materials and Methods: A total sample of 180 EC segments from 3M Unitek®, Ormco® and Ortho Classic® brands were equally divided into 12 groups, each comprising 15 specimens. These pieces were kept in artificial saliva at 37 °C and brushed twice daily for 28 days, with three distinct types of toothpaste: Colgate® Total, Colgate® Max White, and Dr Organic® Extra Whitening Charcoal Toothpaste. The latter two toothpastes contain activated charcoal. Tensile strength, resistance to rupture and colour variation were evaluated at time zero and day 28. Descriptive statistics, one-way ANOVA and Tukey HSD tests were performed at p ≤ 0.05. Results: Toothpaste with and without activated carbon significantly reduced the tensile strength and resistance to rupture of the ECs, and altered EC colour (p < 0.0001). There was inconsistency in the effect of the activated carbon on EC characteristics, most probably due to the different compositions of the ECs and percentages of whitening agents in the toothpastes. Conclusions: The material composition of ECs contributes to their tensile strength decay, resistance to rupture and colour change over time. The variable percentage of activated carbon in a toothpaste likely underlies the different effects observed, depending on the EC brand. Clinical Relevance: It might be reasonable to advise patients wearing ECs to avoid using toothpaste with activated carbon until further evidence becomes available. [ABSTRACT FROM AUTHOR]

Objective This study aimed to test repolishing effect on color stability, translucency, and surface roughness of aged monochromatic dental composite in artificial saliva, tea, mouthwash, and coffee after 1 month, simulating 2.5 years of clinical use. Materials and Methods Omnichroma, a monochromatic dental composite, and Z250 XT a nanohybrid multishade dental composite were used in this study. Specimens (n = 80) from each dental composite were prepared to determine color stability, translucency parameter, and surface roughness after repolishing of aged specimens in artificial saliva, tea, mouthwash, and coffee for 1 month. Scanning electron microscope and laser scanning microscope were used to study surface topography after repolishing. Data was analyzed using analysis of variance, Scheffe test, and independent t -test. Results A significant difference between both dental composites after repolishing in terms of color stability and translucency parameter as that of Omnichroma was higher but sill color changes of Omnichroma were perceptible. There was no difference between both composites in regard to surface roughness after repolishing; however, values of both composites were above the accepted value of 0.2 µm and laser scanning microscope images confirmed these findings. Conclusions Repolishing did not enhance color and surface roughness of aged monochromatic dental composites. [ABSTRACT FROM AUTHOR]

Composite resins are the material of choice for direct restorations, and their success depends mainly on their color stability, since discoloration causes color mismatch, and consequent patient dissatisfaction. A single- and a multi-shade resin were compared in order to evaluate their pigmentation after immersion in staining substances and to investigate the effect of the polymerization time on their color stability. Two-hundred-and-forty composite specimens were created, half made of a single-shade (Group ONE, n = 120) and half of a multi-shade composite (Group OXP, n = 120). Each group was further divided into ONE30 (n = 60) and OXP30 (n = 60), polymerized for 30″, and ONE80 (n = 60) and OXP80 (n = 60), polymerized for 80″. Randomly, the specimens were immersed in turmeric solution, soy sauce, energy drink, or artificial saliva. By means of a spectrophotometer, ΔE00 and WId were calculated at 24 h (T0), at 7 (T1), and 30 (T2) days. Single-shade composites showed statistically significant differences in color change from the turmeric solution, energy drink, and soy sauce than the multi-shade composites (p < 0.005), showing a higher discoloration potential. The polymerization time did not have significative effects on color stability. Single-shade composites showed more color change than multi-shade systems after immersion in staining substances, and the curing time did not influence color variations. [ABSTRACT FROM AUTHOR]

Objective Materials and Methods Results Conclusions Clinical Significance To analyze and compare the impact of acidic media on the surface characteristics of highly filled flowable resin‐based composites.Two hundred fifty‐six specimens were divided into four groups: GUF (G‐aenial Universal Flo), GUI (G‐aenial Universal Injectable), TEF (Tetric EvoFlow), and FSF (Filtek Supreme Flowable Restorative). Surface characteristics were analyzed before (T0) and after specimens immersion in different media, such as gastric juice (GJ), fizzy drink (FD), citric juice (CJ), or artificial saliva (AS), for 9 h (T1) and 18 h (T2). The analyses included surface roughness (SR) measurements, where average roughness (Ra) was obtained, scanning electron microscopy (SEM) analysis, and surface hardness (SH) evaluation, with Vickers numbers (HV) reported. The differences in values among groups/subgroups within the same stage were assessed using two‐way ANOVA and Tukey's post hoc test, whereas repeated measures ANOVA with Bonferroni post hoc test was performed to compare the changes in values through the stages. Data were presented as mean ± standard deviation (SD).At T0, GUI and GUF revealed lower Ra values (p < 0.05), more evenness in SEM micrographs, and higher HV values (p < 0.05) than FSF and TEF. At T1 and T2, specimens of all groups/subgroups demonstrated an increase in Ra and a decrease in HV compared with T0 (p < 0.05), as well as the changes in surface morphology on SEM micrographs. The lowest Ra and highest HV values were observed in GUI group, in contrast to FSF group, and in specimens immersed in GJ.GUI revealed lower SR and higher SH compared to GUF and FSF both before and after exposure to acidic media. The presence of acidic media, especially GJ, significantly increases SR and decreases SH of tested materials.Information on the changes in the surface characteristics of highly filled resin‐based composites after exposure to acidic media may be essential for the longevity of restorations like composite veneers fabricated from these materials. [ABSTRACT FROM AUTHOR]

Introduction: Resin composites have been commonly used in restorative dentistry over the years. The longevity of restorations depends upon various physical properties like as solubility. Composite solubility can lead to deleterious effects on the polymer structure. Aim: To evaluate and compare the solubility of a single shade resin composite in comparison to a conventional resin composite in artificial saliva. Materials and Methods: In the present in-vitro study, 44 pellets (10 mm x 1 mm) were prepared from each material. The pellets were divided into two groups (n=22) based on the immersion period of two days and seven days. They were incubated, weighed using an analytical balance, and then immersed in artificial saliva. Weighing was done again after the completion of the immersion period, and solubility was calculated. Paired and independent sample t-tests were used to compare the solubility of both materials after two days and seven days. Results: The differences of solubility values for the single shade composite and conventional composite at two and seven-day intervals were (p=0.031) and (p=0.019), respectively, which were statistically significant. On inter-group comparison, the difference in solubility of the single shade composite at two days was significantly lower compared to conventional composites (p=0.024). Whereas, no significant difference was observed in solubility values between both groups at seven days (p=0.102). Conclusion: The performance of the single shade composite in terms of solubility was better in comparison with conventional composite. [ABSTRACT FROM AUTHOR]

Simulated body fluid (SBF) and artificial saliva (AS) are used in biomedical and dental research to mimic the physiological conditions of the human body. In this study, the biomimetic precipitation of double-doped amorphous calcium phosphate in SBF and AS are compared by thermodynamic modelling of chemical equilibrium in the SBF/AS-CaCl2-MgCl2-ZnCl2-K2HPO4-H2O and SBF/AS-CaCl2-MgCl2-ZnCl2-K2HPO4-Glycine/Valine-H2O systems. The saturation indices (SIs) of possible precipitate solid phases at pH 6.5, close to pH of AS, pH 7.5, close to pH of SBF, and pH 8.5, chosen by us based on our previous experimental data, were calculated. The results show possible precipitation of the same salts with almost equal SIs in the two biomimetic environments at the studied pHs. A decrease in the saturation indices of magnesium and zinc phosphates in the presence of glycine is a prerequisite for reducing their concentrations in the precipitates. Experimental studies confirmed the thermodynamic predictions. Only X-ray amorphous calcium phosphate with incorporated Mg (5.86–8.85 mol%) and Zn (0.71–2.84 mol%) was obtained in the experimental studies, irrespective of biomimetic media and synthesis route. Solid-state nuclear magnetic resonance (NMR) analysis showed that the synthesis route affects the degree of structural disorder of the precipitates. The lowest concentration of dopant ions was obtained in the presence of glycine. Further, the behaviour of the selected amorphous phase in artificial saliva was studied. The dynamic of Ca2+, Mg2+, and Zn2+ ions between the solid and liquid phases was monitored. Both direct excitation 31P NMR spectra and 1H-31P CP-MAS spectra proved the increase in the nanocrystalline hydroxyapatite phase upon increasing the incubation time in AS, which is more pronounced in samples with lower additives. The effect of the initial concentration of doped ions on the solid phase transformation was assessed by solid-state NMR. [ABSTRACT FROM AUTHOR]

Sutures are natural or synthetic biomaterials utilized to hold tissues together. Following oral surgery, the surgical site and sutures are physically affected by many different factors. This study was conducted to evaluate the effect of artificial saliva (AS) and chlorhexidine mouthwash on the tensile strength of absorbable multifilament PGLA (polyglycolide-co-l-lactide) and non-absorbable multifilament silk sutures. PGLA and silk sutures, which are commonly used in oral surgery, were used to evaluate the change in strength of the sutures. A total of 352 suture samples were divided into eight equal groups (n = 44) and used for the experiments. Tensile strength was tested on days 0, 3, 7, and 14. For the silk sutures, there was a significant decrease in tensile strength in all groups at time T3 compared to T0, T1, and T2, and at times T1 and T2 compared to T0. For PGLA sutures, there was a significant decrease in all groups at time T3 compared to T0, T1, and T2. This study shows that chlorhexidine mouthwash significantly reduces suture resistance for 14 days after surgery. [ABSTRACT FROM AUTHOR]

Preventing or treating infections at implantation sites where the risk of bacterial contamination is high requires the development of intelligent drug delivery systems. The objective of this work was to develop a production method and characterization of fourth-generation oxide nanotubes on titanium grade 4 surface as a potential drug carrier. This study focused on the anodizing process; physico-chemical characterization using FE-SEM, EDS, and FTIR; in vitro corrosion resistance in an artificial saliva solution; and determining the drug release kinetics of gentamicin sulfate using UV-VIS. The anodizing process was optimized to produce fourth-generation oxide nanotubes in a fluoride-free electrolyte, ensuring rapid growth and lack of order. Results showed that the length of the oxide nanotubes was inversely proportional to the anodizing voltage, with longer nanotubes formed at lower voltages. The nanotubes were shown to have a honeycomb structure with silver particles co-deposited on the surface for antibacterial properties and were capable of carrying and releasing the antibiotic gentamicin sulfate in a controlled manner, following Fick's first law of diffusion. The corrosion resistance study demonstrates that the oxide nanotubes enhance the corrosion resistance of the titanium surface. The oxide nanotubes show promise in enhancing osseointegration and reducing post-implantation complications. [ABSTRACT FROM AUTHOR]

The assessment of the mucoadhesive properties peak mucoadhesive force (F max) and work of mucoadhesion (W muc) with texture analyzers is a common in vitro method for analyzing formulation capabilities. Challenges arise in selecting and standardizing experimental conditions due to various variables influencing mucoadhesion. This complexity hampers direct product performance comparisons. In our study, we explored factors (contact force and time, probe speed and mucin in artificial saliva) impacting a model formulation's mucoadhesive capacity. Using Omcilon-A®Orabase on porcine buccal mucosa, we systematically varied experimental conditions, employing a statistical approach (Central Composite Design - CCD). Three variables (contact force, contact time, probe speed) and their interactions were assessed for their impact on F max and W muc. Results showed that contact time and force positively affected F max , while only contact time influenced W muc. In the mucin artificial saliva test, a force of 0.5 N, time of 600 s, and speed of 1 mm/s yielded optimal F max (0.587 N) and W muc (0.468 N.s). These conditions serve as a reference for comparing mucoadhesive properties of formulations for topical oral use. [Display omitted] [ABSTRACT FROM AUTHOR]

Regular monitoring of blood glucose levels is crucial in diabetes management. Commonly used procedures may be invasive and can lead to cross-infection and inflammation. Therefore, a safe, non-invasive blood glucose-monitoring technology is needed. Herein, a 3D reduced graphene oxide (rGO) electrode was modified with MXene (Ti3C2) and gold nanoparticles (AuNPs) to construct a non-invasive, saliva glucose detection electrode. The Au/rGO-Ti3C2 electrode exhibited good detection performance for glucose concentrations in the range of 10 µM–21 mM at a working potential of 0.6 V, with a detection limit of 3.1 µM glucose, and a sensitivity of 355 µA mM−1 cm−2. The Au/rGO-Ti3C2 electrode showed almost no response to the addition of interfering substances, and no effect was observed upon subsequent glucose detection. The sensor could detect glucose in artificial saliva and saliva supernatant. The modified electrode showed a significant response to low glucose concentrations, even at 10 µM. These results indicate the suitability of the Au/rGO-Ti3C2 electrode for saliva glucose detection. The electrode developed in this study has great potential in improving the efficiency of diabetes monitoring through pain-free, non-invasive glucose detection in saliva. [ABSTRACT FROM AUTHOR]

Suture materials are natural or synthetic biomaterials used to close tissues together. After surgical procedures in the mouth, the surgical site and the sutures are physically affected by many different factors. This study was conducted to evaluate the effects of frequently consumed beverages on the tensile strength of monofilament PGLA (polyglycolide-co-l-lactide) and multi-filament PGCL (polyglycolide-co-caprolactone) absorbable sutures. In particular, PGLA and PGCL absorbable sutures, which are frequently used in oral surgery, were used to evaluate the change in the strength of suture materials. The suture materials were soaked in tea, coffee, and cola drinks five times a day for 5 min each and the rest of the time in artificial saliva. All suture materials were aged via thermal cycling. Tensile strengths were tested at 0, 3, 7, and 14 days. Mixed ANOVA (four replicates: within-group comparison and two factors: between-group comparison) was performed to evaluate the effects of groups and time on the tension levels of the Tekmon and Vicryl suture materials. Analysis of Variance was used for the within- and between-group comparisons, with the Bonferroni corrected t-test for multiple comparisons. For the PGCL suture material, there were significant decreases in tension levels in artificial saliva, tea, coffee, and cola at time T3 compared to T0, T1, and T2, and at T1 and T2 compared to T0. For the PGLA suture material, there were significant decreases in tension levels in artificial saliva, tea, coffee, and cola at time T3 compared to T0, T1, and T2. There was also a significant decrease in tension level at time T2 in cola compared to T0. The present study demonstrates that beverages significantly decrease the strength of suture materials for 14 days after surgery. In particular, cola decreased the resistance of the PGCL suture material more significantly in the first week when compared to other beverages. [ABSTRACT FROM AUTHOR]

Purpose: The effects of different remineralization agents applied on enamel samples were evaluated by using surface and subsurface microhardness analysis. Methods: Sixty bovine incisor enamel samples were fabricated. After the initial microhardness values were measured, enamel samples are divided into 3 equal parts, and assigned as the treatment area (T), the adjacent area (A) and the control area (C) (covered with an acid-resistant varnish). Samples were subjected to pH cycle for 5-days, and then microhardness measurements were repeated. The specimens were randomly divided into 5 groups according to the fluoridereleasing materials applied, as follows: Group 1: BioMin F; Group 2: Colgate Triple Effect; Group 3: FCP COMPLEX; Group 4: Fluor Protector; Group 5: Artificial saliva (control). Following the applications, surface and subsurface measurements were performed. The data were analyzed by one-way analysis of variance (ANOVA) and post-hoc Tukey test. Results: BioMin F toothpaste provided the greatest increase in surface microhardness, followed by FCP COMPLEX, Colgate Triple Effect and Fluor Protector, respectively. Among the materials tested, BioMin F and Colgate toothpastes exhibited the highest increase in subsurface microhardness values, with FCP COMPLEX solution following closely in second place. Conclusions: BioMin F showed the best results in the surface microhardness assessment, while both toothpastes (BioMin F and Colgate) showed similarly positive results in the subsurface microhardness assessment. [ABSTRACT FROM AUTHOR]

Objective: White spot lesions are one of the most common problem during and after orthodontic therapy. The present study was accomplished to evaluate the ability of Magnesium gel at different concentration and diode laser in combination compared with commercially available 1.23%APF in color restoring of WSL on permanent teeth. Materials and Methods: In this in vitro study, 42 human caries-free premolar teeth were randomely divided into 6 experimental groups: Group A: Control (artificial saliva), Group B: 0.5%MgCl2 gel, Group C: 1%MgCl2 gel, Group D: 0.5%MgCl2 gel and Diode laser, Group E: 1%MgCl2 gel and Diode laser and Group F: 1.23%APF. The difference between the displayed color and the original color standard (ΔE) was assessed by colorimeter. The surface topography of teeth samples from each tested group was examined by a SEM. Collected data were investigated using one-way ANOVA followed by Duncan post hoc test at p ≤ 0.05. Result: A significant difference in (ΔE) was noticed among groups (p= 0.006). Group (B) showed the lowest ΔE value (9.4±1.6), followed by group (D) (10.2±1.1), group (F) (10.4±2.6), group (A) (11.6±1.3), group (C) (12.9 ±2.3) and group (E) (13.2±1.3). Conclusion: 0.5% magnesium gel is as 1.23% APF gel in color restoring of white spot lesion. No synergistic effect between materials and diode laser. [ABSTRACT FROM AUTHOR]

(1) Background: PETG (polyethylene terephthalate glycol) is a transparent, inexpensive, and versatile thermoplastic biomaterial, and it is increasingly being used for a variety of medical applications in dentistry, orthopedics, tissue engineering, and surgery. It is known to have remarkable properties such as tensile strength, high ductility, and resistance to chemical insults and heat, but it can be affected by various environmental conditions. The aim of the present study was to evaluate the topographical characteristics of four thermoplastic dental appliance materials in relation to water sorption in simulated oral environments (artificial saliva samples with different pH values). (2) Methods: The following four types of PETG clear thermoplastic materials were selected for the present study: Leone (L), Crystal (C), Erkodur (E), and Duran (D). In relation to the desiccation and water-uptake stages, their water sorption (Wsp) and solubility (Wsl) were calculated, and the surface topographies were analyzed on two length scales. The surface roughness was determined using a contact profilometer, and nanoroughness measurements were generated by three-dimensional profiles using an atomic force microscope (AFM). Statistical analyses (one-way ANOVA and unpaired and paired Student t-tests) were performed. (3) Results: After saliva immersion, the weights of all samples increased, and the highest sorption was recorded in a basic environment. Among the materials, the water uptake for the L samples was the highest, and for E, it was the lowest. In relation to water solubility, significant values were registered for both the L and C samples' materials. After immersion and desiccation, a decreasing trend in microroughness was observed. The AFM high-resolution images reflected more irregular surfaces related to saliva immersion. (4) Conclusions: The sorption rates recorded in water-based artificial saliva were higher for basic pH levels, with significant differences between the samples. There were also significant differences related to the behaviors of the materials included in the study. In relation to roughness, on a microscale, the surfaces tended to be smoother after the saliva immersions, and on a nanoscale, they became more irregular. [ABSTRACT FROM AUTHOR]

Objectives: Radiation‐induced dry mouth negatively impacts patients' oral health and quality of life. Currently, evidence‐based recommendation for non‐pharmacologic interventions is still lacking. This study aimed to systematically review clinical trials evaluating the efficacy of non‐pharmacologic interventions in cancer patients with radiation‐induced dry mouth. Methods: Randomized controlled trials from 2000 were searched from 4 databases, including MEDLINE, Cochrane, Embase via OVID, and SCOPUS, up to December 16th, 2022 (PROSPERO registration CRD42022378405). The risk of bias was assessed using the revised Cochrane risk of bias assessment tool. Results: Twenty‐one studies were included: 11 on artificial saliva, 4 on electrical nerve stimulation (TENS), 2 on acupuncture, and one study each on low‐level laser therapy, stem cells, chewing gum, and probiotics. Overall bias was low, medium, and high in 33%, 48%, and 19% of the studies, respectively. Certain artificial saliva products and TENS were shown to improve dry mouth symptoms and salivary flow rate (SFR). One study showed that stem cell transplantation significantly increased SFR. Conclusions: The evidence suggested that certain artificial saliva products and TENS are promising management. However, the evidence was still limited due to heterogeneity of interventions and outcome measurements. Thus, future studies using standard measurements and long‐term follow‐up are warranted. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printing is increasingly used to fabricate dental restorations due to its enhanced precision, consistency and time and cost-saving advantages. The properties of 3D-printed resin materials can be influenced by the chosen printing orientation which can impact the mechanical characteristics of the final products. The objective of this study was to evaluate the influence of printing orientation and artificial ageing on the Martens hardness (HM) and indentation modulus (E IT) of 3D-printed definitive and temporary dental restorative resins. Disk specimens (20 mm diameter × 2 mm height) were additively manufactured in three printing orientations (0°, 45°, 90°) using five 3D-printable resins: VarseoSmile Crownplus (VCP), Crowntec (CT), Nextdent C&B MFH (ND), Dima C&B temp (DT), and GC temp print (GC). The specimens were printed using a DLP 3D-printer (ASIGA MAX UV), while LavaTM Ultimate (LU) and Telio CAD (TC) served as milled control materials. Martens hardness (HM) and indentation modulus (E IT) were tested both before and after storage in distilled water and artificial saliva for 1, 30, and 90 days at 37 °C. 90° printed specimens exhibited higher HM than the other orientations at certain time points, but no significant differences were observed in HM and E IT between orientations for all 3D-printed materials after 90 days of ageing in both aging media. LU milled control material exhibited the highest HM and E IT among the tested materials, while TC, the other milled control, showed similar values to the 3D printed resins. CT and VCP (definitive resins) and ND displayed higher Martens parameters compared to DT and GC (temporary resins). The hardness of the 3D-printed materials was significantly impacted by artificial ageing compared to the controls, with ND having the least hardness reduction percentage amongst all 3D-printed materials. The hardness reduction percentage in distilled water and artificial saliva was similar for all materials except for TC, where higher reduction was noted in artificial saliva. The used 3D printed resins cannot yet be considered viable alternatives to milled materials intended for definitive restorations but are preferable for use as temporary restorations. [ABSTRACT FROM AUTHOR]

Clinical failure of dental resin-composite restorations is mainly due to bacterial-mediated secondary caries formation. Therefore, the development of a flowable resin-composite material having inherent antibacterial properties is crucial to enhance the durability of dental restorations. Herein, dental flowable resin-composite material was modified with chlorhexidine-loaded mesoporous silica nanoparticles (CHX-MSN) to induce in situ antibacterial properties against S. mutans. Mesoporous silica nanoparticles loaded with chlorhexidine (CHX-MSN) were formulated and characterized for drug-loading/encapsulation efficiency, morphology by electron microscopy, and infrared spectral analysis. CHX-MSN were incorporated into the flowable composite material at different concentrations of 1, 5, and 10% (w/w) and examined at two time points (baseline and 3 months in artificial saliva). The CHX-MSN modified composites exhibited an initial CHX release burst followed by a steady release up to 30 days. The antimicrobial efficacy of the modified composites was evaluated by crystal violet assay, MTT assay, and confocal laser scanning microscopy. In addition to measuring the degree of conversion and cytotoxicity, the mechanical properties were characterized by surface microhardness and flexural strength. The modified composites demonstrated a significant increase in antimicrobial properties compared to the unmodified control (p < 0.05) which is dependent on the concentration of the CHX-MSN nanoparticles. In addition, the modified composites possessed acceptable biocompatibility without adversely affecting mechanical properties and degree of conversion up to 5% addition of CHX-MSN nanoparticles. This study introduced a protocol to develop resin-based flowable dental composite material having superior antibacterial property against cariogenic biofilms aiming for enhancing clinical longevity of dental restorations. [ABSTRACT FROM AUTHOR]

Aerosol transmission remains a major challenge for control of respiratory viruses, particularly those causing recurrent epidemics, like influenza A virus (IAV). These viruses are rarely expelled alone, but instead are embedded in a consortium of microorganisms that populate the respiratory tract. The impact of microbial communities and inter-pathogen interactions upon stability of transmitted viruses is well-characterized for enteric pathogens, but is under-studied in the respiratory niche. Here, we assessed whether the presence of five different species of commensal respiratory bacteria could influence the persistence of IAV within phosphate-buffered saline and artificial saliva droplets deposited on surfaces at typical indoor air humidity, and within airborne aerosol particles. In droplets, presence of individual species or a mixed bacterial community resulted in 10- to 100-fold more infectious IAV remaining after 1 h, due to bacterial-mediated flattening of drying droplets and early efflorescence. Even when no efflorescence occurred at high humidity or the bacteria-induced changes in droplet morphology were abolished by aerosolization instead of deposition on a well plate, the bacteria remained protective. Staphylococcus aureus and Streptococcus pneumoniae were the most stabilizing compared to other commensals at equivalent density, indicating the composition of an individual’s respiratory microbiota is a previously unconsidered factor influencing expelled virus persistence. IMPORTANCE It is known that respiratory infections such as coronavirus disease 2019 and influenza are transmitted by release of virus-containing aerosols and larger droplets by an infected host. The survival time of viruses expelled into the environment can vary depending on temperature, room air humidity, UV exposure, air composition, and suspending fluid. However, few studies consider the fact that respiratory viruses are not alone in the respiratory tract—we are constantly colonized by a plethora of bacteria in our noses, mouth, and lower respiratory system. In the gut, enteric viruses are known to be stabilized against inactivation and environmental decay by gut bacteria. Despite the presence of a similarly complex bacterial microbiota in the respiratory tract, few studies have investigated whether viral stabilization could occur in this niche. Here, we address this question by investigating influenza A virus stabilization by a range of commensal bacteria in systems representing respiratory aerosols and droplets. [ABSTRACT FROM AUTHOR]

An innovative pharmaceutical form for administering melatonin, based on starch orodispersible film (ODF), was designed and prepared. The composition of the ODF included starch as the polymer matrix, the active drug melatonin, and a plasticizer. Melatonin, a natural hormone produced by the pineal gland in the brain, can be absorbed by passive diffusion across the mucous membrane, resulting in improved bioavailability when compared to conventional oral administration. This study shows a simple and efficient method for preparing melatonin-loaded orodispersible films with a physically stable and commercially viable matrix, suitable for use in the pharmaceutical industry. The films were prepared by treating the starch with microwave irradiation, followed by plasticization with glycerol, melatonin loading and drying by solvent casting. Mechanical tests showed the films' robustness, with a modulus of approximately 97 MPa, indicating good handling properties. Moisture uptake analysis showed fast water absorption, reaching about 150% within 2 min, indicating its fast oral disintegration potential. Disintegration tests in artificial saliva and dissolution studies indicated the release of the drug in minutes, indicating the potential properties of the film for oral drug delivery. To the best of our knowledge, there is no melatonin ODF based on starch described in the literature. [ABSTRACT FROM AUTHOR]

Background: To evaluate colour stability in artificial saliva by mechanically simulating brushing between in-house 3D-printed resin brackets (IH3DBs) and commercially available brackets. Methods: The samples consist of four sets of ten aesthetic brackets each supplied by four different manufacturers: clear Damon, Synovate C, Crystal and in-house 3D printed brackets (IH3DBs). The brackets were immersed in a plastic tank containing artificial saliva maintained at a constant temperature of 37 °C with a 65-minute brushing system. Staining changes at T0 (pre-brushing) and T1 (post-brushing) were measured with a spectrophotometer according to the VITA and Master scale and brightness values. Statistical analysis compared the colour changes with the Wilcoxon test and in case of significance, severity was investigated. The significance level considered was p < 0.05. Results: The IH3DBs shows statistically significant differences for both scales and brightness values. The Damon and the Crystal brackets report a statistically significant difference only for brightness. The Synovate C bracket shows no statistically significant differences. Conclusions: The IH3DB produced chromaticity differences for the VITA and Master scale possibly due to the surface roughness created during the printing process. However, the IH3DBs together with Damon Clear improved brightness, due to the mechanical action of brushing. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the effect of blood and artificial salivary contamination of different root-end filling materials on microleakage using a confocal laser scanning microscope and on marginal adaptation using a scanning electron microscope. Materials and Methods: Eighty noncarious single-rooted teeth with mature apices were taken. After retro-cavity preparation, they were randomly assigned into two major groups (n = 40). They were contaminated with blood and artificial saliva, respectively. Each major group was divided randomly into four subgroups (n = 10) and filled as follows: Subgroup A, Biodentine; Subgroup B, bioactive bone cement; Subgroup C, Cention N; and Subgroup D, Bio-C Repair. The samples were sectioned transversely at 1 and 2 mm from the root apex and checked under a confocal laser scanning microscope for microleakage and under an scanning electron microscope for marginal adaptation. The average mean values were calculated. Independent samples t-tests, paired t-tests, and one-way analysis of variance with Tukey's post hoc tests were done to analyze the data. Results: All the tested materials showed marginal gaps and dye leakage. The Bio-C Repair group showed the least mean marginal gap and dye leakage values, followed by bioactive bone cement, Biodentine, and Cention N, respectively, in both blood and artificial saliva contamination. However, the mean marginal gaps and dye leakage between the major groups were statistically insignificant. Conclusion: In an overall comparison, Bio-C Repair was found to be superior in terms of marginal adaptation and sealing ability under the test conditions. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this in vitro study was to assess the efficiency of incorporating Biosilicate particles (30 and 50 mg) into an experimental orodispersible film and its efficacy in the remineralization process of bovine dental enamel under cariogenic and erosive challenges. Methods: Ninety‐nine intact incisors, devoid of cracks or fractures, yielding 198 samples (6 × 6 × 2 mm) via vestibular sectioning using a low‐speed diamond disc under water cooling. After flattening the enamel surface with 600, 1200, and 2000 grit sandpaper, the samples were divided into two groups based on the challenges they underwent: cariogenic (0.1 M lactic acid at pH 5.0) or erosive (0.05 M citric acid solution at pH 2.3). Samples from each challenge were further categorized into 11 groups (n = 9) according to the duration of cariogenic (3, 7, and 14 days) or erosive (3, 7, and 10 days) challenge, along with positive control groups (fragments untreated with challenges and treated with different Biosilicate concentrations) and negative controls (fragments treated with artificial saliva for the same periods established for cariogenic and erosive challenges). Treatments with orodispersible films containing Biosilicate (30 and 50 mg) were administered for 2 min per day for 15 days. Results: The highest remineralizing potential was observed in samples treated with Biosilicate after 14 days of cariogenic challenge, irrespective of the concentration tested. For samples subjected to erosive challenge, erosion time did not affect Biosilicate's remineralizing potential. Conclusion: Biosilicate shows promise in terms of remineralizing potential in enamel subjected to cariogenic challenge due to its ability to form hydroxycarbonapatite in mineralized tissues. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the bleaching efficacy and effects on enamel properties of experimental gels with carbamide peroxide (CP; 10%) or hydrogen peroxide (HP; 6%) containing calcium polyphosphate sub-microparticles (CaPPs). Methods: A total of 216 bovine tooth specimens were divided for microhardness and color analyses (n = 108) and block randomized into nine groups (n = 12): (G1) commercial CP (Whiteness Perfect, FGM; Brazil); (G2) experimental CP; (G3) CP-0.5%CaPPs; (G4) CP-1.5%CaPPs; (G5) commercial HP (Potenza Bianco, PHS; Brazil); (G6) experimental HP; (G7) HP-0.5%CaPPs; (G8) HP-1.5%CaPPs; (G9) artificial saliva. The gels' pH values were determined with a bench pH meter. Color (ΔE, ΔE00, ΔWID) and microhardness variation were evaluated before and after the therapy. Part of the specimens used for microhardness was submitted to the scanning electron microscopy (SEM) (n = 3) and energy-dispersive X-ray spectroscopy EDX (n = 3) analyses. Statistical analyses were performed in the R statistical software (α = 0.05). Linear mixed models for repeated measures in time were used to analyze microhardness and L* values. Generalized linear models were used to analyze the a*, b*, ΔE, ΔE00, and ΔWID, considering a group effect. The EDX data were analyzed using a one-way ANOVA with Tukey's test. Results: The gels' pH remained over 6,0. All gels effectively bleached the specimens and did not differ significantly. When compared to the control group, the hardness was significantly lower in the G1, G2, G6, and G7 groups. The G3, G4, G5, and G8 groups did not differ significantly (p > 0.05). Conclusion: The incorporation of CaPPs in low-concentration whitening gels reduces its negative effects on microhardness without interfering with their bleaching efficacy. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effects of fluoridated varnishes supplemented with micrometric or nanosized sodium trimetaphosphate (TMPmicro or TMPnano, respectively) against enamel softening in an early erosive model in vitro. Bovine enamel blocks (with mean surface hardness [SH] between 330.0 and 380.0 kgf/mm2) were selected and randomly assigned according to their SH (n = 8) into the following groups: Placebo (no fluoride/TMP; negative control), 5% NaF (positive control), 5% NaF + 5%TMPmicro, 5% NaF + 2.5%TMPnano and 5% NaF + 5%TMPnano. Blocks received a single application of the varnishes and were immersed in artificial saliva (6 h). Thereafter, the varnishes were removed and the blocks were subjected to four individual erosive challenges (1 min, citric acid, 0.75%, pH = 3.5, under agitation); SH was determined after each challenge. Data were subjected to ANOVA and Student–Newman–Keuls' test (p < 0.05). Overall, the highest %SH loss was observed for the Placebo, followed by 5% NaF, 5% NaF + 5% TMPmicro, and both varnishes containing TMPnano, without significant differences between 2.5% and 5% TMPnano. It was concluded that TMP enhanced the effects of a 5% NaF varnish against enamel softening in an early erosive model in vitro, with an additional benefit from the use of nanoparticles over microparticles. [ABSTRACT FROM AUTHOR]

Cortisol is a clinically validated stress biomarker that takes part in many physiological and psychological functions related to the body's response to stress factors. In particular, it has emerged as a pivotal tool for understanding stress levels and overall well-being. Usually, in clinics, cortisol levels are monitored in blood or urine, but significant changes are also registered in sweat and saliva. In this work, a surface plasmon resonance probe based on a D-shaped plastic optical fiber was functionalized with a glucocorticoid receptor exploited as a highly efficient bioreceptor specific to cortisol. The developed plastic optical fiber biosensor was tested for cortisol detection in buffer and artificial saliva. The biosensor response showed very good selectivity towards other hormones and a detection limit of about 59 fM and 96 fM in phosphate saline buffer and artificial saliva, respectively. The obtained detection limit, with a rapid detection time (about 5 min) and a low-cost sensor system, paved the way for determining the cortisol concentration in saliva samples without any extraction process or sample pretreatment via a point-of-care test. [ABSTRACT FROM AUTHOR]

Here, ternary layer hydroxide (NiCoFe-LDH) nanosheets have been grafted in situ onto graphene oxide (GO) using a one-pot hydrothermal method to obtain NiCoFe-LDH/GO for the fabrication of a non-enzymatic glucose sensor with high stability. SEM analysis shows that ternary LDHs with a nanosheet layer structure grow on GO at an angle with less stacking, thus imparting NiCoFe-LDH/GO with a large specific surface area (112.32 m2 g−1) that exposes more active sites. The results of cyclic voltammetry (CV) and chronoamperometry (CA) studies show that NiCoFe-LDH/GO/GCE displays a wide linear detection range of 0.005–7.54 mM, a sensitivity of 196.18 μA cm−2 mM−1, and a low detection limit of 0.41 μM (S/N = 3). In particular, NiCoFe-LDH/GO/GCE has high stability, that is, it still holds 90.2% of its initial value even after 90 days. Meanwhile, the study results demonstrate that the NiCoFe-LDH/GO/GCE electrode is suitable for the detection of glucose in artificial saliva, and it also reveals a good recovery ranging from 95.6% to 105.5% in actual saliva. Therefore, NiCoFe-LDH/GO is anticipated to be an ideal sensing material for the creation of noninvasive enzyme-free glucose sensors. [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) printing is becoming more prevalent in the dental sector due to its potential to save time for dental practitioners, streamline fabrication processes, enhance precision and consistency in fabricating prosthetic models, and offer cost‐effective solutions. However, the effect of aging in artificial saliva of this type of material has not been explored. To assess the physical and mechanical properties of the two types of 3D‐printed materials before and after being subjected to artificial saliva, a total of 219 acrylic resin specimens were produced. These specimens were made with two types of 3D‐printed materials, namely, NextDent (ND) and Formlabs (FLs), and a Schottlander heat‐cured (HC) resin material that was used as a control. Water sorption and solubility specimens (n = 5) were tested after three months of storage in artificial saliva. Moreover, the Vickers hardness, Martens hardness, flexural strength/modulus, and impact strength were evaluated both under dry conditions and after three months of storage in artificial saliva. The degree of conversion (DC), elemental analysis, and filler content were also investigated. The ANOVA showed that 3D‐printed resins had significantly greater sorption than the control group (p < 0.05). However, the flexural strength values of the 3D‐printed materials were significantly greater (p < 0.05) than those of the heat‐cured material. The DC of the 3D‐printed resins was lower than that of the control group, but the difference was not significant (p > 0.05). The 3D‐printed materials contained significantly more filler than the control (p < 0.05). Moreover, the artificial saliva had a significant effect on the Vickers hardness for all tested groups and on the Martens hardness for the control group only (p < 0.05). Compared with conventional heat‐cured materials, 3D‐printed denture base materials demonstrated relatively poorer performance in terms of sorption, solubility, and DC but exhibited either comparable or superior mechanical properties. The aging process also influenced the Vickers and Martens' hardness. The strength of the 3D‐printed materials was in compliance with ISO recommendations, and the materials could be used alongside conventional heat‐cured materials. [ABSTRACT FROM AUTHOR]

Salivary pH is one of the crucial biomarkers used for non-invasive diagnosis of intraoral diseases, as well as general health conditions. However, standard pH sensors are usually too bulky, expensive, and impractical for routine use outside laboratory settings. Herein, a miniature hydrogel sensor, which enables quick and simple colorimetric detection of pH level, is shown. The sensor structure was manufactured from non-toxic hydrogel ink and patterned in the form of a matrix with 5 mm × 5 mm × 1 mm individual sensing pads using a 3D printing technique (bioplotting). The authors' ink composition, which contains sodium alginate, polyvinylpyrrolidone, and bromothymol blue indicator, enables repeatable and stable color response to different pH levels. The developed analysis software with an easy-to-use graphical user interface extracts the R(ed), G(reen), and B(lue) components of the color image of the hydrogel pads, and evaluates the pH value in a second. A calibration curve used for the analysis was obtained in a pH range of 3.5 to 9.0 using a laboratory pH meter as a reference. Validation of the sensor was performed on samples of artificial saliva for medical use and its mixtures with beverages of different pH values (lemon juice, coffee, black and green tea, bottled and tap water), and correct responses to acidic and alkaline solutions were observed. The matrix of square sensing pads used in this study provided multiple parallel responses for parametric tests, but the applied 3D printing method and ink composition enable easy adjustment of the shape of the sensing layer to other desired patterns and sizes. Additional mechanical tests of the hydrogel layers confirmed the relatively high quality and durability of the sensor structure. The solution presented here, comprising 3D printed hydrogel sensor pads, simple colorimetric detection, and graphical software for signal processing, opens the way to development of miniature and biocompatible diagnostic devices in the form of flexible, wearable, or intraoral sensors for prospective application in personalized medicine and point-of-care diagnosis. [ABSTRACT FROM AUTHOR]

Introduction: Extrinsic tooth staining can be caused by external factors such as food and coffee. Brushing teeth with toothpaste is one way to clean up initial tooth staining. Whitening toothpaste is widely used as it is believed to be able to remove tooth staining. Siwak is also known to have the ability to inhibit tooth staining. This study aims to determine the effectiveness of commercial whitening toothpaste and toothpaste containing Siwak extract in inhibiting coffee-induced extrinsic staining on clear acrylic resin. Materials and methods: This research was pre and post-test laboratory experimental using a sample of 80 blocks of clear acrylic resin with a size of 35 x 11.5 x 11.5 mm. The samples were divided into 4 groups: whitening toothpaste A (ingredients whitening teeth effect), whitening toothpaste B (for cigarettes and coffee), whitening toothpaste C (containing Siwak extract), and a control group (distilled water). The alternative was to soak clear acrylic in artificial saliva, toothpaste, chlorhexidine, and coffee. Measurement of color change was carried out by UV-vis spectrophotometer. Results: The Kruskal Wallis test revealed p > 0.05 for whitening toothpaste B (for cigarette and coffee) and p < 0.05 for whitening toothpaste A, toothpaste C containing Siwak, and controls. The most effective toothpaste in inhibiting extrinsic staining due to coffee using means rank was Siwak extract toothpaste. Conclusion: Whitening toothpaste containing Siwak extract was the most effective in inhibiting extrinsic staining due to coffee compared to other commercial whitening toothpaste. [ABSTRACT FROM AUTHOR]

Mental illnesses, such as clinical depression, have taken an unprecedented toll on society and the economy on a global scale. The relationship between stress management and mental health decline is of utmost significance, especially as most avenues of mental health management remain inaccessible for the majority of the general public, i.e., interview-based, and face-to-face interventions or costly drug-based therapies. Cortisol, the primary stress hormone, regulates the stress response in the human body and, through persistent activation, can lead to chronic stress and mental health deterioration. Thereby, the measurement and evaluation of cortisol within saliva could harness potential developments in management and diagnostic tools to monitor physiological and psychological stress in simple point-of-care applications. The current study aims to determine the concentration of salivary cortisol in spiked artificial saliva samples using blue tetrazolium (BT) dye as a colorimetric indicator. The proposed method showcases the use of the BT dye as an effective method for the rapid measurement of salivary cortisol, with accuracy comparable to the gold-standard method for salivary cortisol analysis, enzyme-linked immunoassays (ELISAs). Finally, a prototype colorimetric sensor has been developed for point-of-care applications of stress monitoring via salivary cortisol measurement. [ABSTRACT FROM AUTHOR]

The electrochemical behaviour of the Co–Cr–Mo–W alloy in the Fusayama synthetic saliva was examined as a function of fluoride ion concentration, pH level, and immersion time using open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The OCP results showed that the rate of growth of the air-formed film on the Co–Cr–Mo–W alloy surface lowers as the concentration of the F– ions added to saliva increases. Additionally, in all of the pH values of saliva examined (from 2 to 11), the OCP became more positive over time, indicating the development of the native film on the alloy. The results of impedance and potentiodynamic polarization revealed that the corrosion resistance of the primarily produced oxide layer on the alloy decreased with an increase in the F– ions in saliva, but increased with an increase in saliva pH value. According to the EIS findings, the thickness of the anodic oxide film on the Co–Cr–Mo–W alloy increases with rising pH levels in the formation medium (saliva). By using energy-dispersive X-ray spectroscopy (EDS), it was discovered that as the salvia pH rises, the amount of oxygen on the alloy surface increases, indicating the development of a protective oxide layer. The surface roughness of the mechanically polished alloy surface rises with anodic polarization in an alkaline saliva solution, according to atomic force microscopy. The results of scanning electron microscopy and EIS show that as the alloy is immersed in saliva for a longer time, the thickness of the air-formed film on the alloy increases. [ABSTRACT FROM AUTHOR]

Objective: Colour stability is important in the long-term aesthetic success of restorative materials and is affected by both internal and external factors. Internal discolourations are due to the properties of the restorative materials. External discolourations can be associated with frequent consumption of food and beverages and the use of suspensions or syrups containing colourants/additives. Fluoride varnish application has an important place in preventive dentistry. The purpose of the research was to examine the protective effect of fluoride varnish application on the colour change on polyacid-modified composite resin restorative materials caused by the use of various paediatric drugs. Methods: Two hundred ten discs were prepared from polyacid-modified composite resin material and divided into two groups: flouride varnish was applied to one group and flouride varnish was not applied to the other group. The groups were further divided into seven subgroups and the samples were kept in artificial saliva, amoxicillin + clavulanic acid, cefuroxime axetil, clarithromycin, paracetamol, ibuprofen, and iron supplement drug solutions. The colour change values of the discs were measured using a spectrophotometer device before immersion in the drug solutions and on the 7th, 14th, 21st, and 28th days after the immersion. The obtained data were calculated and statistically evaluated using IBM SPSS V23 software. Results: It was found that the application of fluoride varnish in the iron supplement drug group prevented the colour change of the polyacid-modified composite resins for 28 days. In the amoxicillin + clavulanic acid, cefuroxime axetil, and paracetamol groups, the fluoride varnish did not prevent colour change in the polyacid-modified composite resin restorative materials at the end of the 14th day. Conclusion: It is thought that fluoride varnish application may be beneficial as a preservative in the colour change of polyacid-modified composite resins due to the use of various paediatric drugs, and this protective feature may be effective for a specific period of time. [ABSTRACT FROM AUTHOR]