Effect of blood and artificial saliva contamination on marginal adaptation and sealing ability of different retrograde filling materials: A comparative analysis.

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.

Thermodynamic and Kinetic Studies of the Precipitation of Double-Doped Amorphous Calcium Phosphate and Its Behaviour in Artificial Saliva.

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.

Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study.

Introduction: The cycles of demineralization and remineralization result in a dynamic process of caries development. Caries are prevented by the shift in the balance from demineralization to remineralization at the tooth-oral fluid interface with the help of salivary fluoride levels (in parts per million). The advantages of fluoride varnish application over other substitutes like dentifrices, mouthrinses, gels, or foams are that varnishes are well tolerated by infants, young children, or children with special healthcare needs and have prolonged therapeutic effects. This study was formulated to evaluate and compare the longevity of fluoride release from different fluoride varnishes, namely Fluor Protector, Enamelast, and Enamel Pro varnish. Aim: To evaluate and compare the longevity of fluoride release from three different fluoride varnishes. Materials and methods: The study samples comprised 72 healthy permanent maxillary anterior teeth. The teeth were divided into four groups, with eighteen teeth in each group. The surfaces of all teeth were then covered by different colored nail varnish according to the respective group, except for a 3 × 3 mm window on the facial (labial) surface of the crown, where the test materials were applied according to their respective group. In group I, Fluor Protector varnish; in group II, Enamelast varnish; and in group III, Enamel Pro varnish was applied. Group IV was the control group; hence, no test material was applied. All specimens were then stored in plastic containers with a pH of 7.2 in artificial saliva at room temperature. The specimens were transferred into new plastic containers after 1 day, containing fresh artificial saliva, and solutions from previous plastic containers were taken for fluoride analysis. This process was repeated sequentially to analyze the amount of fluoride released in ppm from the specimens at the end of 1, 3, and 6 months. Statistical analysis: Analysis was performed on Statistical Package for the Social Sciences (SPSS) software (Windows version 22.0). Results: Conventionally used 1.5% ammonium fluoride varnish, that is, Fluor Protector varnish, showed the least release of fluoride (0.03 ± 0.0 ppm), while resin carrier-based 5% sodium fluoride varnish, that is, Enamelast varnish showed a good amount of fluoride release for 6 months continuously, that is, (0.16 ± 0.06 ppm) at last follow-up. Enamel Pro varnish, which has 5% sodium fluoride with amorphous calcium phosphate (ACP) formula, was found to be the best varnish as it released the maximum amount of fluoride in ppm in artificial saliva for up to 3 months (0.32 ± 0.08) but less than Enamelast varnish only at 6 months follow-up that is 0.09 ± 0.03 ppm. Conclusion: The present study concludes that based on the amount of fluoride released for 6 months duration, Enamel Pro varnish, followed by Enamelast varnish and Fluor Protector varnish, are advisable to apply for caries prevention. How to cite this article: Singh V, Naik S, Vashisth P, et al. Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study. Int J Clin Pediatr Dent 2024;17(3):341-345.

A Comparative In Vitro Physicochemical Analysis of Resin Infiltrants Doped With Bioactive Glasses.

Objective This study aimed to investigate the longevity and effectiveness of bioactive glass (BAG)-based dental resin infiltrants. Materials and methods The three types of BAG - 45S5 bioglass (RIS), boron-substituted (RIB), and fluoride-substituted (RIF) - were incorporated with photoinitiated dimethacrylate monomers to create experimental resin infiltrants. ICON® (CN; DMG-America, Ridgefield Park, NJ) and pure resin (PR) were used as control groups in this study. Disc-shaped samples were prepared for the experimental and control groups. The samples were challenged with the pH cycle and immersed in the artificial saliva for 30 days. On Day 0 and Day 30, the pH cycle and artificial saliva immersion, Vicker's microhardness, surface roughness, and surface morphology were investigated. Results The RIF group's disc samples showed the highest Vicker's microhardness values (78.20 ±0.06) on Day 30 of artificial saliva immersion, whereas the CN group's values were the lowest (55.99 ±0.24). Following the pH cycling, the RIF displayed the highest hardness (64.15 ±1.89) whereas the CN group's values were the lowest (33.47 ±1.28). Regarding surface roughness, on Day 30, the RIB resin group exhibited the highest (1.14 ±0.001 µm). In contrast, the CN resin showed the lowest (1.07 ±0.06 µm) values, while immersed in the artificial saliva solution. In the same duration of time, in the pH cycling solution, PR showed the least (0.85 ±0.89 µm), while RIF showed the highest roughness value (0.94 ±0.54 µm). Morphological analysis revealed that following the artificial saliva immersion, the RIB, CN, and PR exhibited smoother surfaces compared to the RIS and RIF groups. However, when immersed in the pH cycling solution, RIB and RIF showed more resistance against acid attack. Conclusions Our results revealed that the experimental resin groups performed much better than the commercial resin infiltrants following artificial saliva and pH cycling challenges.

Fabrication and characterization of Ti-12Mo/xAl2O3 bio-inert composite for dental prosthetic applications.

Introduction: Titanium (Ti)-molybdenum(Mo) composites reinforced with ceramic nanoparticles have recently significant interest among researchers as a new type of bio-inert material used for dental prosthetic applications due to its biocompatibility, outstanding physical, mechanical and corrosion properties. The current work investigates the impact of alumina (Al2O3) nanoparticles on the properties of the Ti-12Mo composite, including microstructure, density, hardness, wear resistance, and electrochemical behavior. Methods: Ti-12Mo/xAl2O3 nanocomposites reinforced with different Al2O3 nanoparticles content were prepared. The composition of each sample was adjusted through the mechanical milling of the elemental constituents of the sample for 24 h under an argon atmosphere. The produced nanocomposite powders were then cold-pressed at 600 MPa and sintered at different temperatures (1,350°C, 1,450°C, and 1,500°C) for 90 min. Based on density measurements using the Archimedes method, the most suitable sintering temperature was found to be 1,450°C. The morphology and chemical composition of the milled and sintered composites were analyzed using back-scattering scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results and Discussion: The results showed that the addition of Mo increased the Ti density from 99.11% to 99.46%, while the incorporation of 15wt% Al2O3 in the Ti-12Mo composite decreased the density to 97.28%. Furthermore, the Vickers hardness and wear behavior of the Ti-Mo composite were enhanced with the addition of up to 5 wt% Al2O3. The sample contains 5 wt% Al2O3 exhibited a Vickers hardness of 593.4 HV, compared to 320 HV for pure Ti, and demonstrated the lowest wear rate of 0.0367 mg/min, compared to 0.307 mg/min for pure Ti. Electrochemical investigations revealed that the sintered Ti-12Mo/xAl2O3 nanocomposites displayed higher corrosion resistance against a simulated artificial saliva (AS) solution than pure Ti. The concentrations of Ti, Mo, and Al ions released from the Ti-12Mo/xAl2O3 nanocomposites in the AS solution were within the safe levels. It was found from this study that; the sample of the composition Ti-12Mo/5wt%Al2O3 exhibited appropriate mechanical properties, biocompatibility, corrosion resistance against the AS solution with acceptable ion concentration released in the biological fluids. Therefore, it can be considered as a new bio-inert material for potential applications in dental prosthetics.

Surface Topography of Thermoplastic Appliance Materials Related to Sorption and Solubility in Artificial Saliva.

(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.

Examining enamel-surface demineralization upon exposure to acidic solutions and the remineralization potential of milk and artificial saliva.

The enamel surface may undergo demineralization due to exposure to acidic substances and the remineralization of the etched enamel is crucial to regain or maintain integrity. This study aimed to investigate the erosive effect of 10 acidic solutions on tooth enamel and the remineralization capacity of milk and artificial saliva by measuring surface roughness (Ra), enamel depth, and microhardness. A total of 80 bovine incisor enamel specimens were immersed in 10 different acidic solutions, including four different acidic drinks, three different citric acid solutions, and three different citric acid buffer solutions, for 1 h. After demineralization, the specimens were immersed in milk and artificial saliva for 3 h. Surface roughness, enamel abraded depth, and microhardness were measured before demineralization, in-between time intervals and after remineralization. Data were analyzed using Friedman and Kruskal-Wallis tests (p < 0.05). The results indicate a significant difference in surface roughness between the measurements taken at different time intervals, particularly between the baseline and after 1 h demineralization. Also, the specimens immersed in CAB1 exhibited greatest increase in Ra among other acidic solutions (Δ: 0.18 ± 0.07). Moreover, only the microhardness increased after remineralization (p < 0.05). Enamel demineralization using various acidic solutions revealed increased Ra and enamel abraded depth, and decreased microhardness. The use of remineralization agents, milk and artificial saliva, demonstrated an increase in microhardness. This study provides insights into the effects of different acidic solutions and potential remineralization agents on tooth enamel.

Electrochemical dissolution and retrieval of broken NiTi endodontic files from root canal using chloride based isotonic fluids as electrolytes - An in vitro study.

Objective: The electrochemical dissolution method of instrument retrieval emphasizes on the dissolution of the instrument rather than sacrificing dentine. Most of the studies conducted for electrochemical dissolution used fluoride-containing electrolytes and were performed inside a beaker. In this study, we used chloride-based fluids as electrolytes. Materials and Methods: Fifty extracted mandibular first premolars were divided into five groups based on the electrolytes used. Canals were enlarged to ProTaper Universal F2, and files were intentionally broken inside the canal. These specimens were subjected to electrochemical characterization by applying the potential of 9V for 20 min. Optical images were taken to assess the change in surface topography. The results were analyzed statistically by one-way analysis of variance (analysis of variance [ANOVA]). Results: The rate of dissolution based on the electrolyte used decreased in the following order, viz. Tyrode's solution>artificial saliva>normal saline>Ringer's lactate/physiological serum. Conclusion: Apart from fluoride, chloride-based electrolytes could be an efficient alternative.

The effect of artificial saliva on the control of dry mouth: a semi-experimental study on COVID-19 patients under Non-invasive mechanical ventilation.

OBJECTIVES: Since maintaining oral hygiene is essential in nursing care, the present study was conducted to determine the effect of oral care using Mucosamin artificial saliva spray to control dry mouth in ICU patients with COVID-19. MATERIALS AND METHODS: The current semi-experimental research was conducted on eighty patients with COVID-19 selected using the available sampling method. The study tool was a Beck oral assessment scale (BOAS). The case and control groups were selected from two hospitals with relatively similar conditions and treatment procedures. For patients in the intervention group, mucosamin artificial saliva spray was used in addition to the common care, while control group patients received only common care. RESULTS: Eighty patients were randomly assigned to two groups named control and intervention (40 patients in each group). The intervention was very effective in reducing the BOAS score after four days in comparison with the control group (9.23 vs. 12.05, respectively; p-value < 0.001). Based on the adjusted model, the application of artificial saliva reduced the BOAS score, indicating improvement in mouth dryness. While the BOAS score was increased in the control group, it had a declining trend in the intervention one. CONCLUSION: The study's results showed that using artificial saliva spray could effectively reduce the symptoms of dry mouth in patients with COVID-19 treated with non-invasive mechanical ventilation. CLINICAL RELEVANCE: The present study introduced an applicable solution (artificial saliva) to treat mouth dryness in ICU patients under mechanical ventilation.

Effect of a Nano-hydroxyapatite Toothpaste on Enamel Erosive Lesions of Third Molars Induced by Exposure to Orange Juice.

Objectives: This study aimed to assess the effect of a nano-hydroxyapatite (nano-HA) toothpaste on erosive enamel lesions of third molars induced by exposure to orange juice. Materials and Methods: In this in vitro, experimental study, the microhardness of 24 sound-extracted third molars was measured by a Vickers tester. The teeth were then randomly assigned to three groups (n = 8) of nano-HA toothpaste (Pharmed), 1.23% sodium fluoride gel, and artificial saliva. The teeth were exposed to orange juice for 5 min daily for 7 days and were then exposed to nano-HA toothpaste, fluoride gel, or artificial saliva (depending on their group allocation) for 10 min a day. The microhardness of the teeth was measured again after 7 days. Data were analyzed using paired t-test, analysis of variance, and Bonferroni test (alpha = 0.05). Results: Within-group comparisons showed a significant reduction in microhardness of the teeth after the intervention in artificial saliva (P = 0.000), and fluoride gel (P = 0.002) groups. However, no significant reduction occurred in the microhardness of the nano-HA group, compared with the baseline (P = 0.132). Between-group comparisons revealed no significant difference in the microhardness of the three groups at baseline (P > 0.05). However, after the intervention, the microhardness of the nano-HA group was significantly higher than that of other groups (P < 0.05). However, the difference in secondary microhardness between fluoride gel and artificial saliva groups was not significant (P = 1.00). Conclusion: Pharmed toothpaste containing nano-HA has optimal efficacy for remineralization of enamel erosive lesions induced by exposure to orange juice.

The Effect of Aging on Artificial Saliva at Different pH Values on the Color Stability of New Generation Denture Base Materials.

STATEMENT OF PROBLEM: New-generation denture base materials are used successfully in denture fabrication; however, the effect of saliva pH change on the color stability of materials is unknown. PURPOSE: The purpose of this in vitro study is to evaluate the color stability of new-generation denture base materials after immersion in artificial saliva with different pH values (3,7,14). MATERIAL AND METHODS: Disc-shaped samples (Ø 10 mm x 2 mm) were prepared from three different denture base materials (1 pre-polymerized polymethylmethacrylate [PMMA], 1 graphene-reinforced PMMA, and heat-cure polymethyl methacrylate resin) (n=10). After polishing, color coordinates were measured using a PCE-CSM 5 colorimeter programmed in the CIE system (L* a* b*). The samples were kept in artificial saliva at different pH values and 37°C for 21 days. At the end of 21 days, color coordinates were measured again. The suitability of the measurements for a normal distribution was examined with the Kolmogro-Smirnov test. Whether color measurements obtained at different pH levels differed according to groups was examined with the Kruskal-Wallis test. The correlation between the CIEDE2000 and CIELab color difference formulas was examined by correlation analysis. RESULTS: The highest color difference occurred in heat-cure samples at pH 3 (p<0.001). The color difference at different pH values was least observed in pre-polymerized PMMA samples. Significant color differences occurred in the graphene-reinforced pre-polymerized PMMA group at pH 7 (p<0.001). CONCLUSIONS: It was observed that color differences occurred in all groups. Dentures made of new-generation CAD/CAM PMMA, which are less exposed to color differences, can be recommended for elderly patients with systemic diseases who are frequently exposed to pH changes in the oral cavity. CLINICAL IMPLICATIONS: Color differences on denture surfaces over time negatively affect aesthetics. Since pH changes cause changes on the prosthesis surface, it may be recommended for these patients to fabricate dentures from new-generation CAD/CAM PMMA resins, which are less deformable.

The influence of oral cavity physiological parameters: temperature, pH, and swelling on the performance of denture adhesives - in vitro study.

BACKGROUND: The various physical and chemical conditions within the oral cavity are hypothesized to have a significant influence on the behavior of denture adhesives and therefore the overall comfort of denture wearers. As such, this study aims to understand the influence of oral cavity physiological parameters such as temperature (17 to 52 °C), pH (2, 7, 10), and denture adhesive swelling due to saliva (20-120%) on the behavior of denture adhesives. This study further aims to emphasize the need for a collective approach to modelling the in-situ behavior of denture adhesives. METHODS: Rheological measurements were carried out using the Super Polygrip Ultra fresh brand denture adhesive cream to evaluate its storage modulus (G´) and loss modulus (G´´) values at a range of physiologically relevant temperatures, pH values, and degrees of swelling, to represent and characterize the wide variety of conditions that occur within the oral cavity. RESULTS: Rheological data was recorded with respect to variation of temperature, pH, and swelling. Overall, it can be seen that the physiological conditions of the oral cavity have an influence on the rheological properties of the denture adhesive cream. Specifically, our data indicates that the adhesive's mechanical properties are weakly influenced by pH, but do change with respect to the temperature in the oral cavity and the swelling rate of the adhesive. CONCLUSIONS: Our results suggest that the collective inter-play of the parameters pH, temperature and swelling ratio have an influence on the behavior of the denture adhesive. The results clearly highlight the need for developing a multi-parameter viscoelastic material model to understand the collective influence of physiological parameters on the performance of denture adhesives. Multi-parameter models can also potentially be utilized in numerically simulating denture adhesives using finite element simulations.

Potencial remineralizante de una saliva sintética: estudio in vitro / Remineralizing potential of synthetic saliva: an in vitro study / Potencial remineralizador de uma saliva sintética: um estudo in vitro

RESUMEN Objetivo : Evaluar el efecto remineralizante de una saliva sintética en el esmalte dental bovino erosionado. Materiales y métodos : Se prepararon 50 bloques de esmalte de dientes de bovino. Las muestras fueron divididas en 5 grupos de estudio según el tratamiento: grupo A (Colgate Total®, pasta de dientes que contiene fluoruro), grupo B (MI Paste Plus®, pasta de dientes que contiene fosfopéptido de caseína-fosfato de calcio amorfo [CPP-ACP] con fluoruro), grupo C (Salival® Solución, saliva sintética), grupo D (agua destilada) y grupo E (sin tratamiento). Todos los especímenes de los grupos A, B, C y D recibieron ataques con ácido cítrico al 0,5 % durante 2 minutos a las 0, 8, 24 y 32 horas. Después de cada ataque ácido, se aplicaron las pastas de dientes correspondientes a cada grupo de tratamiento. Luego se procedió a evaluar el grado de mineralización mediante microscopía Raman y la microdureza superficial mediante microdureza Vickers. Resultados : Respecto al grado de mineralización y la dureza superficial, no se encontraron diferencias significativas (p > 0,05) en el esmalte dental bovino erosionado tratado con Colgate Total®, MI Paste Plus® y Salival® Solución en comparación con las muestras de esmalte sano; sin embargo, todas presentaron un grado de mineralización y dureza superficial significativamente mayor que las muestras de esmalte de dientes bovinos erosionados conservados en agua destilada (p < 0,05). Conclusión : Este estudio in vitro muestra que la saliva sintética Salival® Solución tiene un potencial remineralizante en el esmalte bovino erosionado.

ABSTRACT Objective : To evaluate the remineralizing effect of synthetic saliva on eroded bovine dental enamel. Materials and methods : 50 enamel blocks were prepared from bovine teeth. The specimens were divided into 5 study groups according to treatment: group A (Colgate Total®, toothpaste containing fluoride), group B (MI Paste Plus®, toothpaste containing casein phosphopeptide, amorphous calcium phosphate [CPP-ACP] with fluoride), group C (Salival® Solution, synthetic saliva), group D (distilled water) and group E (no treatment). All specimens in groups A, B, C and D received 0.5% citric acid attacks for 2 minutes at 0, 8, 24 and 32 hours. After each acid attack, toothpastes corresponding to each treatment group were applied. The degree of mineralization was then evaluated by Raman microscopy and surface microhardness by Vickers microhardness. Results : Regarding the degree of mineralization and surface hardness, no significant differences (p > 0.05) were found in the eroded bovine tooth enamel treated with Colgate Total®, Mi Paste Plus® and Salival® Solution in comparison with the healthy enamel samples. But all presented a significantly higher degree of mineralization and surface hardness than the eroded bovine tooth enamel samples preserved in distilled water (p < 0.05). Conclusion : This in vitro study shows that the synthetic saliva Salival® Solution has a remineralizing potential on eroded bovine enamel.

RESUMO Objetivo : Avaliar o efeito remineralizante de uma saliva sintética no esmalte dentário bovino erodido. Materiais e métodos : Foram preparados 50 blocos de esmalte de dentes de bovinos. As amostras foram divididas em 5 grupos de estudo de acordo com o tratamento: grupo A (Colgate Total®, pasta dentífrica contendo flúor), grupo B (MI Paste Plus®, pasta dentífrica contendo fosfopeptídeo de caseína, fosfato de cálcio amorfo [CPP-ACP] com flúor), grupo C (Salival® Solution, saliva sintética), grupo D (água destilada) e grupo E (sem tratamento). Todos os espécimes dos grupos A, B, C e D receberam um ataque ácido cítrico a 0,5% durante 2 minutos às 0, 8, 24 e 32 horas. Após cada ataque ácido, foram aplicadas as pastas dentífricas correspondentes a cada grupo de tratamento. O grau de mineralização foi então avaliado por microscopia Raman e a microdureza superficial por microdureza Vickers. Resultados : Relativamente ao grau de mineralização e à dureza da superfície, não foram encontradas diferenças significativas (p > 0,05) no esmalte dentário bovino erodido tratado com Colgate Total®, Mi Paste Plus® e Salival® Solution em comparação com as amostras de esmalte saudável. Mas todos mostraram um grau significativamente mais elevado de mineralização e dureza superficial do que as amostras de esmalte de dentes de bovinos erodidos preservados em água destilada (p < 0,05). Conclusão : Este estudo in vitro mostra que a saliva sintética Salival® Solution tem um potencial remineralizante no esmalte bovino erodido.

Properties of three collagen scaffolds in comparison with native connective tissue: an in-vitro study.

PURPOSE: To evaluate collagen scaffolds (CS) in terms of their in vitro resorption behavior, surface structure, swelling behavior, and mechanical properties in physiologically simulated environments, compared with porcine native connective tissue. MATERIALS AND METHODS: Three test materials-one porcine collagen matrix (p-CM), two acellular dermal matrices (porcine = p-ADM, allogenic = a-ADM)-and porcine native connective tissue (p-CTG) as a control material were examined for resorption in four solutions using a high-precision scale. The solutions were artificial saliva (AS) and simulated body fluid (SBF), both with and without collagenase (0.5 U/ml at 37 °C). In addition, the surface structures of CS were analyzed using a scanning electron microscope (SEM) before and after exposure to AS or SBF. The swelling behavior of CS was evaluated by measuring volume change and liquid absorption capacity in phosphate-buffered saline (PBS). Finally, the mechanical properties of CS and p-CTG were investigated using cyclic compression testing in PBS. RESULTS: Solutions containing collagenase demonstrated high resorption rates with significant differences (p < 0.04) between the tested materials after 4 h, 8 h and 24 h, ranging from 54.1 to 100% after 24 h. SEM images revealed cross-linked collagen structures in all untreated specimens. Unlike a-ADM, the scaffolds of p-CM and p-ADM displayed a flake-like structure. The swelling ratio and fluid absorption capacity per area ranged from 13.4 to 25.5% among the test materials and showed following pattern: p-CM > a-ADM > p-ADM. P-CM exhibited higher elastic properties than p-ADM, whereas a-ADM, like p-CTG, were barely compressible and lost structural integrity under increasing pressure. CONCLUSIONS AND CLINICAL IMPLICATIONS: Collagen scaffolds vary significantly in their physical properties, such as resorption and swelling behavior and elastic properties, depending on their microstructure and composition. When clinically applied, these differences should be taken into consideration to achieve the desired outcomes.

Quantifying the Release of Titanium From the Titanium Dioxide-Impregnated Composites Used in Orthodontic Bonding.

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.

A Comparative Evaluation of the Effect of Different Beverages on Colour Stability and Surface Micromorphology of Nanocomposite Restorative Material.

AIM: This investigation was carried out to evaluate the color stability of a nanocomposite restorative material and the erosive potential of carbonated soft drinks (Coca-Cola; The Coca-Cola Company, Atlanta, Georgia, United States) and packaged orange juice (Real Fruit Power Orange; Dabur Ltd, Ghaziabad, Uttar Pradesh, India) on its surface micromorphology. MATERIALS AND METHODS: Sixty discs (2mm thick and 10mm diameter) of nanocomposite material (Herculite Précis; KaVo Kerr, Brea, California, United States) were prepared using a silicon cylindrical mold. Initially, all the specimens were stored in artificial saliva in five Petri dishes; 12 specimens in each dish. In the Petri dishes, the specimens were immersed in the respective beverages once or twice a day. Before and after each immersion, the specimens were stored in artificial saliva at room temperature. Artificial saliva was changed each day, i.e., every 24 hours. The whole procedure was carried out for three months and then evaluated for color stability using a spectrophotometer and surface micromorphology using a scanning electron microscope. Now, the exposure of specimens to aerated drinks (Coca-Cola) and packaged orange juice (Real Orange) was put to a halt, and specimens were kept continuously in artificial saliva. This procedure was carried out for one month and then evaluated for color stability. The information was analyzed using PASW Statistics for Windows, Version 18.0 (Released 2009; SPSS Inc., Chicago, United States). A p-value of 0.05 was considered significant. RESULTS: The p-value after three months, which is < 0.001 (p<0.05) indicates that the mean color difference values for groups I, II, III, IV, and V show a statistically significant change between the five groups, and similarly, the p-value after one month, which is < 0.001 (p<0.05) indicates that the mean color difference values for groups I, II, III, IV, and V show a statistically significant change between the five groups. Specimens immersed in the carbonated drink twice a day showed clinically more color change than packaged orange juice and artificial saliva on the composite restorative material. Coca-Cola, an aerated drink, was shown to have a higher erosive potential on the composite restorative material than Real Fruit Power Orange and fake saliva. CONCLUSION: The findings are consistent with the hypothesis that repeated exposure to carbonated beverages (such as Coca-Cola and packaged juice) degrades the surface qualities of dental restorations.

Influence of Different Mouth Rinsing Agents on Friction During Sliding Mechanics Between Orthodontic Metal Brackets and Stainless Steel Archwire: A Comparative In Vitro Study.

Aim and objectives The aim of this in-vitro study is to evaluate and compare the effect of various mouth rinsing agents on frictional resistance through sliding mechanics among orthodontic metal brackets and stainless steel (SS) archwire. Materials and methods Each group comprised 15 samples of maxillary first premolar pre-adjusted edgewise SS movable, un-bonded brackets (Koden Inc., United States) which were welded with a power arm, where 100 g of the load was suspended. Brackets were ligated with elastic modules (Koden Inc., United States) onto the perspex sheet along with 0.019" x 0.025" SS archwire (Classic Orthodontics, United States) and were suspended from the upper component of the Instron machine. The coefficient of friction was tested in dry conditions (control), artificial saliva (AS) (Wet Mouth, ICPA Health Product Ltd., India), 0.2% chlorhexidine gluconate (CHG) mouthwash (Hexidine, ICPA Health Product Ltd., India), 0.05% sodium fluoride (NaF) mouthwash (ACT Anti-Cavity Fluoride Mouthwash, Sanofi Company, United States), charcoal (CC) mouthwash (Hello Activated Charcoal Extra Freshening Mouthwash, Hello Products LLC, United States) and ozone-infused oil-pulling solution with coconut oil (O3) (O3 Essentials, Health Ranger Store, United States). In order to calculate the coefficient of friction, 50 L was added to the test sample while moving at a 5 mm/min crosshead speed. The groups were compared using the one-way analysis of variance (ANOVA), and Tukey's post hoc analysis was performed for multiple pairwise comparisons. Results The coefficient of friction with the highest mean values was observed with the control group (2.01), followed by AS (1.79), and the least with O3 (1.15). Statistically significant differences were observed with almost all groups of mouth rinsing agents, but NaF is significant with CHG and CC. However, CHG did not have any significant difference from CC. Conclusions Lower coefficient of frictional values were observed with the ozone-infused oil-pulling solution with coconut oil during sliding mechanics between metal brackets and stainless steel archwire. Almost all the mouth rinsing agents showed a significantly different coefficient of friction value.

A Review of the Role of Natural Products as Treatment Approaches for Xerostomia.

Xerostomia, commonly known as dry mouth, is a widespread oral health malfunction characterized by decreased salivary flow. This condition results in discomfort, impaired speech and mastication, dysphagia, heightened susceptibility to oral infections, and ultimately, a diminished oral health-related quality of life. The etiology of xerostomia is multifaceted, with primary causes encompassing the use of xerostomic medications, radiation therapy to the head and neck, and systemic diseases such as Sjögren's syndrome. Consequently, there is a growing interest in devising management strategies to address this oral health issue, which presents significant challenges due to the intricate nature of saliva. Historically, natural products have served medicinal purposes, and in contemporary pharmaceutical research and development, they continue to play a crucial role, including the treatment of xerostomia. In this context, the present review aims to provide an overview of the current state of knowledge regarding natural compounds and extracts for xerostomia treatment, paving the way for developing novel therapeutic strategies for this common oral health issue.

An in vitro evaluation of aligner force decay in artificial saliva.

Background/purpose: The present study aimed to compare the force decay of invisible aligners for maxillary anterior teeth with 0.1 mm (D1), 0.2 mm (D2), and 0.3 mm (D3) 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 (D1), 0.2 mm (D2), and 0.3 mm (D3) 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 D2 and D3 groups under simulated oral environment force (SF) (P < 0.05). There was a significant difference in force decay between Day 1 and Day 7 for all groups (P < 0.05). The SFD1 group showed a significant decrease in force on Day 5 (P < 0.05), while the SFD2 and SFD3 groups showed significant force decay on Day 4 (P < 0.05). The force decay ratio on Day 7 was higher in the SFD3 group than in the SFD1 and SFD2 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.

The Impact of Commercially Available Dry Mouth Products on the Corrosion Resistance of Common Dental Alloys.

Dental implants are thought to be implanted for life, but throughout their lifespan, they function in aggressive oral environment, resulting in corrosion of the material itself as well as possible inflammation of adjacent tissues. Therefore, materials and oral products for people with metallic intraoral appliances must be chosen carefully. The purpose of this study was to investigate the corrosion behavior of common titanium and cobalt-chromium alloys in interaction with various dry mouth products using electrochemical impedance spectroscopy (EIS). The study showed that different dry mouth products lead to different open circuit potentials, corrosion voltages, and currents. The corrosion potentials of Ti64 and CoCr ranged from -0.3 to 0 V and -0.67 to 0.7 V, respectively. In contrast to titanium, pitting corrosion was observed for the cobalt-chromium alloy, leading to the release of Co and Cr ions. Based on the results, it can be argued that the commercially available dry mouth remedies are more favorable for dental alloys in terms of corrosion compared to Fusayama Meyer's artificial saliva. Thus, to prevent undesirable interactions, the individual characteristics of not only the composition of each patient's tooth and jaw structure, but also the materials already used in their oral cavity and oral hygiene products, must be taken into account.