Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 11.444
Filtrar
1.
J Texture Stud ; 55(4): e12854, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38960864

RESUMO

The effect of varying extrusion conditions on the functional properties of hulless barley-mung bean (70:30) extruded snacks was investigated using response surface methodology with feed moisture (FM), barrel temperature (BT), and screw speed (SS) as process variables. Results revealed significant impacts on functional characteristics with varying extrusion conditions. Bulk density (BD) of extruded snacks ranged from 0.24 to 0.42 g/cm3, showing that lower FM and higher BT results in lower BD while it increased with increasing FM, SS, and BT. The expansion ratio (ER) of extruded snacks ranged between 2.03 and 2.33, showing BT and SS had a desirable positive effect, whereas increasing FM led to decreased ER. Increasing BT and SS depicted a negative effect on water absorption index, whereas FM showed positive effect, which ranged between 4.21 and 4.82 g/g. A positive effect on water solubility index was depicted by BT and SS, which ranges between 9.01% and 13.45%, as higher SS and BT led to starch degradation and increased solubility suggesting better digestibility. The hardness of extruded snacks ranged from 32.56 to 66.88 Newton (N), showing increasing FM increased hardness, whereas higher SS and BT resulted in lowering the hardness. Scanning electronic microscope (SEM) analysis revealed structural changes in extrudates in comparison with nonextruded flour, indicating starch gelatinization and pore formation affected by varying processing parameters. Shifts in absorption bands were observed in Fourier transform infrared spectroscopy (FT-IR), suggesting structural changes in starch and protein. Understanding the effects of extrusion parameters on product properties can help tailored production to meet consumers' preferences and the development of functional snacks with improved nutritional quality.


Assuntos
Manipulação de Alimentos , Hordeum , Lanches , Solubilidade , Vigna , Água , Manipulação de Alimentos/métodos , Vigna/química , Dureza , Farinha/análise , Temperatura , Amido/química
2.
AAPS PharmSciTech ; 25(6): 155, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38960983

RESUMO

Gummy formulations are considered suitable alternatives to traditional oral dosage forms like tablets and capsules due to their merits that include chewability, softness/flexibility, improved drug release, administration without water, appealing organoleptic properties, better patient compliance, easy preparation and usefulness for persons of different ages (e.g. children). Though there is increasing interest in gummy formulations containing drugs, measurable parameters, and specification limits for evaluating their quality are scarce. Quality check forms an essential part of the pharmaceutical development process because drug products must be distributed as consistently stable, safe, and therapeutically effective entities. Consequently, some quality parameters that could contribute to the overall performance of typical gummy formulations were investigated employing six brands of non-medicinal gummies as specimens. Accordingly, key physicochemical and micromechanical characteristics namely adhesiveness (0.009 - 0.028 mJ), adhesive force (0.009 - 0.055 N), chewiness (2.780 - 6.753 N), cohesiveness (0.910 - 0.990), hardness (2.984 - 7.453 N), springiness (0.960 - 1.000), and resilience (0.388 - 0.572), matrix firmness - compression load (2.653 - 6.753 N) and work done (3.288 - 6.829 mJ), rupture (5.315 - 29.016 N), moisture content (< 5%), weight uniformity (< 2.5 g; < 7.5% deviation), and intraoral dissolution pH (≥ 3.5 ≤ 6.8) were quantified to identify measures that may potentially function as specification limits and serve as prospective reference points for evaluating the quality of gummy formulations. Findings from this work contribute to ongoing efforts to standardize the quality control strategies for gummy formulations, particularly those intended for oral drug delivery.


Assuntos
Composição de Medicamentos , Composição de Medicamentos/métodos , Composição de Medicamentos/normas , Química Farmacêutica/métodos , Química Farmacêutica/normas , Comprimidos/química , Dureza , Administração Oral , Liberação Controlada de Fármacos , Excipientes/química , Adesividade , Controle de Qualidade
3.
Anim Sci J ; 95(1): e13977, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38982658

RESUMO

Hard meat has low market value; hence, we used bittern as a novel meat tenderizer for bovine M. semitendinosus, one of a hard muscle. We investigated the effects of beef immersion in bittern, a basic solution primarily comprising MgCl2, on textural properties and water-holding capacity. Muscle samples from M. semitendinosus of Holstein steers were immersed in seven different solutions (RO, NaCl, MgCl2, red wine, pH 3, bittern, and pH 8) and heated at 80°C for 5min. The pH of the beef and immersion solutions, water-holding capacity, and maximum load of the meat were measured. Although beef immersed in red wine (pH 3) had a lower pH and water-holding capacity, that immersed in bittern (pH 8.4) had a higher pH and higher water holding capacity. These results indicate that immersion in acidic red wine may harden beef and that immersion in basic bittern may be more effective in maintaining water-holding capacity and softening beef.


Assuntos
Manipulação de Alimentos , Carne Vermelha , Água , Vinho , Animais , Bovinos , Concentração de Íons de Hidrogênio , Vinho/análise , Manipulação de Alimentos/métodos , Carne Vermelha/análise , Imersão , Qualidade dos Alimentos , Músculo Esquelético , Fenômenos Químicos , Masculino , Soluções , Temperatura Alta , Carne/análise , Dureza
4.
J Texture Stud ; 55(4): e12855, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38992897

RESUMO

The effects of oil type, emulsifier type, and emulsion particle size on the texture, gel strength, and rheological properties of SPI emulsion-filled gel (SPI-FG) and TFSP emulsion-filled gel (TFSP-FG) were investigated. Using soybean protein isolate or sodium caseinate as emulsifiers, emulsions with cocoa butter replacer (CBR), palm oil (PO), virgin coconut oil (VCO), and canola oil (CO) as oil phases were prepared. These emulsions were filled into SPI and TFSP gel substrates to prepare emulsion-filled gels. Results that the hardness and gel strength of both gels increased with increasing emulsion content when CBR was used as the emulsion oil phase. However, when the other three liquid oils were used as the oil phase, the hardness and gel strength of TFSP-FG decreased with the increasing of emulsion content, but those of SPI-FG increased when SPI was used as emulsifier. Additionally, the hardness and gel strength of both TFSP-FG and SPI-FG increased with the decreasing of mean particle size of emulsions. Rheological measurements were consistent with textural measurements and found that compared with SC, TFSP-FG, and SPI-FG showed higher G' values when SPI was used as emulsifier. Confocal laser scanning microscopy (CLSM) observation showed that the distribution and stability of emulsion droplets in TFSP-FG and SPI-FG were influenced by the oil type, emulsifier type and emulsion particle size. SPI-stabilized emulsion behaved as active fillers in SPI-FG reinforcing the gel matrix; however, the gel matrix of TFSP-FG still had many void pores when SPI-stabilized emulsion was involved. In conclusion, compared to SPI-FG, the emulsion filler effect that could reinforce gel networks became weaker in TFSP-FG.


Assuntos
Emulsificantes , Emulsões , Géis , Tamanho da Partícula , Reologia , Proteínas de Soja , Proteínas de Soja/química , Emulsões/química , Emulsificantes/química , Géis/química , Óleos de Plantas/química , Óleo de Palmeira/química , Óleo de Brassica napus/química , Óleo de Coco/química , Dureza , Caseínas/química , Gorduras na Dieta
5.
Oper Dent ; 49(4): 465-474, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38987929

RESUMO

OBJECTIVES: This in vitro study aimed to assess the impact of incorporating calcium glycerophosphate (CaGP) and sodium fluoride (NaF) in addition to 35% hydrogen peroxide concerning the enamel mechanical and morphological properties. METHODS: Specimens of bovine enamel were chosen based on their initial surface hardness (SHi) and subsequently divided into five gel groups (n=12): 1) 35% Hydrogen Peroxide (HP) Gel; 2) HP + 0.1% NaF Gel (HP/NaF); 3) HP + 0.25% CaGP Gel (HP/CaGP); 4) HP + 0.1% NaF + 0.25% CaGP Gel (HP/NaF/CaGP) and 5) HP Blue 35% Gel (HP Blue). The bleaching gels were applied thrice, for 40 min, at intervals of 7 days each. After 21 days, the final surface hardness (SHf), integrated hardness (IH), Polydispersity Index (PdI) and Zeta Potential (Zp), surface roughness (Ra, after and before), and surface/structural analysis by Scanning Electron Microscopy (SEM) were determined. The data were submitted to ANOVA (one-way and two-way) followed by the Student-Newman-Keuls test (α=0.05). RESULTS: The addition of NaF to HP reduced demineralization by 11.5% in relation to HP (p<0.05). The NaF/CaGP association reduction is 22.8 and 20% higher in comparison to HP/NaF/CaGP and HP Blue, respectively. The IH when the PH/NaF/CaGP bleaching gel was applied, was 14% higher compared to HP and HP Blue groups. CONCLUSIONS: It can be concluded that the association of NaF and CaGP with the 35% hydrogen peroxide gel (HP/NaF/CaGP) significantly changed tooth enamel demineralization in terms of surface, depth, roughness, and enamel morphology.


Assuntos
Esmalte Dentário , Peróxido de Hidrogênio , Fluoreto de Sódio , Clareadores Dentários , Esmalte Dentário/efeitos dos fármacos , Bovinos , Animais , Fosfatos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Dureza , Clareamento Dental/métodos , Técnicas In Vitro
6.
Oper Dent ; 49(4): 475-483, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38987928

RESUMO

OBJECTIVES: Using a wetting resin or adhesive system as an instrument lubricant when placing composite layers is commonly practiced to improve handling. This study investigated whether instrument lubricants affected strength, stiffness, or hardness. METHODS: Composite beams (TPH Spectra) were fabricated using a stainless steel mold (25×2.5×2 mm) in two steps, where the second half (12.5 mm) was added and cured against a cured first half (n=15). The composite surface at the open end of the first half was smoothed using an instrument lubricated with wetting resin (Ultradent) or universal adhesive (ScotchBond Universal), enough to prevent sticking, or without lubrication. An additional beam of each group was characterized using scanning electron microscopy. Monolithic specimens were also fabricated. After 24 hour storage (37°C, 100% humidity), the beams' flexural strength and stiffness were determined by four-point bending. Vickers surface hardness was measured on 24-hour composite samples in 2 mm deep acrylic cavities, cured after the surface was smoothed with the two instrument lubricants or no lubricant (n=10). Hardness was remeasured after finishing with a series of contouring and polishing discs. Data were statistically analyzed using ANOVA followed by Student-Newman-Keuls post hoc test at 0.05 significance level. RESULTS: There were significant differences (p<0.001) in flexural strength and stiffness among groups. While strength and stiffness were not affected by using a wetting resin as instrument lubricant, use of a universal adhesive increased strength and stiffness significantly, achieving monolithic values. Scanning electron micrographs showed less porosities at the interface when using instrument lubricants. Surface hardness was significantly reduced in groups in which instrument lubricants were used, but finishing/polishing restored original hardness (p<0.001). CONCLUSIONS: Lubricating an instrument with a wetting agent did not adversely affect physical or surface properties, provided the surface was finished and polished. If a universal adhesive was used as lubricant, the strength and stiffness of a layered composite could be increased, reaching monolithic values.


Assuntos
Resinas Compostas , Resistência à Flexão , Dureza , Lubrificantes , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Lubrificantes/química , Resinas Compostas/química , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário , Humanos
7.
BMC Oral Health ; 24(1): 775, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987748

RESUMO

Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans). Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups (p > 0.05), and the flexural strength was lower in the experimental groups than in the control group (p < 0.05), but no difference was found with Sr-PBG content (p > 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group (p < 0.05). This study demonstrated that 3.75% Sr-PBG exhibits antifungal effects against C. albicans along with suitable physicochemical properties, which may help to minimize the risk of adverse effects associated with harmful microbial living on removable orthodontic appliances and promote the use of various materials.


Assuntos
Resinas Acrílicas , Antifúngicos , Candida albicans , Vidro , Teste de Materiais , Fosfatos , Estrôncio , Propriedades de Superfície , Candida albicans/efeitos dos fármacos , Resinas Acrílicas/química , Estrôncio/farmacologia , Estrôncio/química , Antifúngicos/farmacologia , Vidro/química , Fosfatos/farmacologia , Polimerização , Dureza , Resistência à Flexão , Humanos , Técnicas In Vitro
8.
Clin Exp Dent Res ; 10(4): e916, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38970227

RESUMO

OBJECTIVES: This study assessed the effects of 15% and 20% carbamide peroxide (CP) on color, surface roughness, and hardness of computer-aided design/computer-aided manufacturing (CAD/CAM) dental ceramics. MATERIALS AND METHODS: This in vitro study was conducted on 120 Vita Mark II, Celtra Duo, and Suprinity CAD/CAM ceramic specimens. The ceramic specimens in each group (n = 40) were randomly assigned to two subgroups (n = 20) for polishing and glazing, and their baseline color, surface roughness (Ra), and hardness were assessed. In each subgroup, half of the specimens were exposed to 15% CP, while the other half were exposed to 20% CP. Their color change (ΔE), surface roughness, and hardness were then measured again. Surface roughness, hardness, and color were analyzed sequentially by profilometer, Vickers hardness tester, and spectrophotometer, respectively. Data were analyzed by repeated measures ANOVA, one-way ANOVA, and post hoc Bonferroni test (α = 0.05). RESULTS: The surface roughness of all groups significantly increased after bleaching treatment (p < 0.05). Surface hardness of all groups decreased after bleaching treatment, but this reduction was only significant in Vita Mark II subgroups (glazed, polished, 15%, and 20% CP). The ΔE was not clinically and visually perceivable in any group. CONCLUSION: The present results revealed that concentration of CP and type of surface treatment affected the surface properties of CAD/CAM ceramics. Type of surface treatment only affected the surface hardness of Vita Mark II ceramics (p < 0.05). Concentration of CP had a significant effect only on polished Vita Mark II.


Assuntos
Peróxido de Carbamida , Cerâmica , Cor , Desenho Assistido por Computador , Dureza , Teste de Materiais , Peróxidos , Propriedades de Superfície , Peróxido de Carbamida/química , Propriedades de Superfície/efeitos dos fármacos , Dureza/efeitos dos fármacos , Cerâmica/química , Peróxidos/química , Porcelana Dentária/química , Ureia/química , Ureia/análogos & derivados , Ureia/farmacologia , Clareadores Dentários/química , Humanos , Técnicas In Vitro , Materiais Dentários/química , Espectrofotometria
9.
BMC Oral Health ; 24(1): 789, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003474

RESUMO

BACKGROUND: Currently, the advantages of monochromatic universal composite resin restorative materials have increased their use in dentistry. Accordingly, the optical, surface and mechanical properties of these materials have become more important. This study aimed to evaluate the effect of detox solution on discoloration, surface roughness (SR), and microhardness of different monochromatic universal composite resins (Omnichroma [O], Zenchroma [Z], Vittra [V], and Charisma Diamond One [CDO]). Another aim of this study was to evaluate the monomer conversion degree (DC) of the materials. METHODS: A total of 80 specimens were prepared to evaluate the materials (n = 10). After the initial measurements, the specimens were immersed in a red detox solution for 21 days. Statistical data analysis was performed using one-way ANOVA and Tukey's multiple comparisons. RESULTS: The ∆E values of Z were highest on the 21st day. There was an increase in the SR values of the materials immersed in the detox solution. On the 21st day, top surface microhardness of O was lower than the other materials. There was no statistically significant difference at DC values among material groups. CONCLUSIONS: The use of detox solutions for a commercially recommended period of 21 days is suggested. However, this usage period can cause discoloration in restorative materials. Furthermore, especially in the initial one-week period, detox solution may have a negative impact on the microhardness of the materials. In light of all these data, we recommend the cautious use of detox solutions to prevent adverse effects on restorative materials.


Assuntos
Cor , Resinas Compostas , Dureza , Teste de Materiais , Propriedades de Superfície , Resinas Compostas/química , Materiais Dentários/química
10.
Ann Afr Med ; 23(3): 466-473, 2024 Jul 01.
Artigo em Francês, Inglês | MEDLINE | ID: mdl-39034574

RESUMO

AIM: The aim of the study was to compare the surface roughness and microhardness of bulk-fill composite and nanohybrid composite resin after exposure to three different beverages at different time intervals. METHODOLOGY: In this study, 60 composite discs each for bulk fill and nanohybrid, of dimensions 10 mm × 2 mm were made. Both composites were randomly divided into four subgroups, i.e., 15 samples each for artificial saliva, tea, coffee, and soft drinks which were further subdivided into five samples for three time intervals. Composite resin discs were immersed in beverages for 4 min in 24 h for 7, 15, and 30 days. All samples were evaluated for surface roughness and microhardness before and after immersion. RESULTS: Both the composites showed a significant increase in surface roughness in all the beverages with maximum change in surface roughness observed in nanohybrid composite resin immersed in soft drinks. Furthermore, the microhardness of both the composites was decreased significantly in all beverages with maximum change in microhardness observed in nanohybrid composite resin immersed in soft drinks. CONCLUSIONS: Bulk-fill composite resin has better resistance to surface roughness and higher microhardness as compared to nanohybrid. Furthermore, acidic beverages highly affect the physical properties of both composite resins for longer periods.


Résumé Objectif:Comparer la rugosité de surface et la microdureté du composite Bulk-Fill et de la résine composite nanohybride après exposition à trois boissons différentes à différents intervalles de temps.Matériels et Méthodes:Dans cette étude, 60 disques composites chacun pour remplissage en vrac et nanohybride, de dimensions 10 mm X 2 mm ont été fabriqués. Les deux composites ont été divisés au hasard en quatre sous-groupes, soit 15 échantillons chacun pour la salive artificielle, le thé, le café et les boissons gazeuses, qui ont ensuite été subdivisés en 5 échantillons pendant 3 intervalles de temps. Des disques de résine composite ont été immergés dans des boissons pendant 4 minutes en 24 heures pendant 7, 15 et 30 jours. Tous les échantillons ont été évalués pour la rugosité de surface et la microdureté avant et après immersion.Résultats:Les deux composites ont montré une augmentation significative de la rugosité de surface dans toutes les boissons, un changement maximal de rugosité de surface ayant été observé dans la résine composite nanohybride immergée dans une boisson gazeuse. De plus, la microdureté des deux composites a diminué de manière significative dans toutes les boissons, un changement maximal de microdureté ayant été observé dans la résine composite nanohybride immergée dans une boisson gazeuse.Conclusions:La résine composite de remplissage en vrac a une meilleure résistance à la rugosité de surface et une microdureté plus élevée que la nanohybride. De plus, les boissons acides affectent fortement les propriétés physiques des deux résines composites sur des périodes plus longues.


Assuntos
Bebidas , Resinas Compostas , Dureza , Teste de Materiais , Nanocompostos , Propriedades de Superfície , Resinas Compostas/química , Humanos , Fatores de Tempo , Nanocompostos/química , Chá , Café/química , Técnicas In Vitro , Bebidas Gaseificadas , Saliva Artificial/química
11.
J Indian Prosthodont Soc ; 24(3): 245-251, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946507

RESUMO

AIM: Synthetic inorganic materials are commonly used as reinforcing agents in polyetheretherketone (PEEK) composite, whereas natural organic plant-based reinforcing agents are negligible. Surface hardness, roughness, and wettability are indicative factors of osseointegration behavior to be used as an implant material. This study evaluated micro surface hardness (MSH), nano surface hardness (NSH), surface roughness (SR), and contact angle (CA) of PEEK-Azadirachta indica reinforced at 10 wt%, 20 wt%, and 30 wt%. SETTINGS AND DESIGN: This was an in vitro study. MATERIALS AND METHODS: Neem (A. indica) leaf nanoparticles were prepared and reinforced with PEEK powder at 10%, 20%, and 30% weight ratios by injection molding. Sixty specimens underwent the microhardness and CA testing using a digital microhardness tester, and CA goniometer, respectively, and later nanoindentation test to analyze the nanohardness and SR. STATISTICAL ANALYSIS USED: A one-way ANOVA test with a 95% confidence interval for MSH and NSH, SR, and CA was performed on the samples. A post hoc Bonferroni test was conducted (α = 0.05) to compare the groups. RESULTS: There was a significant increase in nanohardness (P = 0.000) with zero difference in microhardness (P = 0.514). The addition of 10 wt%, 20 wt%, and 30 wt% nanoparticles increased the SR value of the pure PEEK from 273.19 nm to 284.10 (3.99%), 296.91 (8.68%), and 287.54 (5.24%), respectively. In the analysis of the CA, CA 20% shows the lowest angle (63.69) with the highest for control specimens (82.39). There is an increase in the PEEK composite SR with a decrease in CA. CONCLUSIONS: The addition of plant-derived nanoparticles into the PEEK matrix has a significant impact on the hardness and hydrophobicity enhancing cell growth and osteoblastic differentiation during osseointegration of dental implants.


Assuntos
Benzofenonas , Cetonas , Nanopartículas , Polietilenoglicóis , Polímeros , Propriedades de Superfície , Molhabilidade , Polietilenoglicóis/química , Cetonas/química , Nanopartículas/química , Dureza , Técnicas In Vitro , Implantes Dentários , Teste de Materiais/métodos , Folhas de Planta/química
12.
J Indian Prosthodont Soc ; 24(3): 266-272, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946510

RESUMO

AIM: Occurrence of denture stomatitis and prosthesis breakage are common problems faced by elderly people wearing removable dentures. To overcome this, several attempts are made to improve the denture material by addition of antimicrobials without compromising original properties. The aim of the study was to evaluate flexural strength and microhardness of self-cured polymethyl methacrylate (PMMA) denture base resin after addition of Vaccinium macrocarpon (commonly called as cranberry), extract as antimicrobial, at varying proportions. STUDY SETTING AND DESIGN: Experimental in vitro study. MATERIALS AND METHODS: Frozen cranberry fruits were subjected to extraction process in the presence of aqueous solvents. Lyophilized extract was added in proportions of 0, 0.5, 1.0, 1.5, and 2.0 dry wt/wt % into polymer of self-cure PMMA denture base resin. Based on cranberry inclusion, the study comprised one control (0%) and four test groups (0.5%-2%) with total of 100 samples. A three-point bending test for flexural strength was done for fifty study samples (n = 10). Surface of fractured samples was analyzed using a scanning electron microscope (SEM). Microhardness was determined using Vickers hardness test. STATISTICAL ANALYSIS USED: One-way statistical ANOVA test was done to find the difference between groups, followed by Tukey's post hoc test for multiple pairwise comparison. RESULTS: Flexural strength ranged from 66.80 to 69.28 MPa, and a statistically insignificant difference was observed between groups (P > 0.05). SEM evaluation showed uniformly dispersed strands of cranberry extract in PMMA matrix. With higher concentration, less voids were seen. Vickers microhardness value significantly decreased from 15.96 in the control group to 14.57 with 2% cranberry addition (P < 0.05). CONCLUSION: Incorporation of cranberry extract into self-cure PMMA denture base resin, up to 2 dry wt %, did not decline the flexural strength. However, there was a significant decrease in Vickers microhardness values when compared against the control group (0% cranberry inclusion).


Assuntos
Resistência à Flexão , Dureza , Teste de Materiais , Extratos Vegetais , Polimetil Metacrilato , Vaccinium macrocarpon , Polimetil Metacrilato/química , Vaccinium macrocarpon/química , Extratos Vegetais/química , Humanos , Bases de Dentadura , Materiais Dentários/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Técnicas In Vitro
13.
Braz Oral Res ; 38: e062, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39016368

RESUMO

This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.


Assuntos
Resinas Compostas , Resistência à Flexão , Testes de Dureza , Dureza , Teste de Materiais , Resinas Compostas/química , Fatores de Tempo , Análise de Variância , Reprodutibilidade dos Testes , Valores de Referência , Propriedades de Superfície , Temperatura
14.
Scand J Med Sci Sports ; 34(6): e14672, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38887854

RESUMO

Footwear has the potential to reduce soft-tissue vibrations (STV) but responses are highly subject-specific. Recent evidence shows that compressive garments minimizing STV have a beneficial effect on neuromuscular (NM) fatigue. The aim was to determine whether an individualized midsole hardness can minimize STV and NM fatigue during a half marathon. Twenty experienced runners were recruited for three visits: a familiarization session including the identification of midsole minimizing and maximizing STV amplitude (MIN and MAX, respectively), and two half marathon sessions at 95% of speed at the second ventilatory threshold. STV of the gastrocnemius medialis (GM) muscle, running kinetics, foot strike pattern, rating perceived exhaustion (RPE), and midsole liking were recorded every 3 km. NM fatigue was assessed on plantar flexors (PF) before (PRE) and after (POST) the half marathon. At POST, PF central and peripheral alterations and changes in contact time, step frequency, STV median frequency, and impact force frequency as well as foot strike pattern were found in both MIN and MAX. No significant differences in damping, STV main frequency, flight time, duty factor, and loading rate were observed between conditions whatever the time period. During the half marathon, STV amplitude of GM significantly increased over time for the MAX condition (+13.3%) only. Differences between MIN and MAX were identified for RPE and midsole liking. It could be hypothesized that, while significant, the effect of midsole hardness on STV is too low to substantially affect NM fatigue.


Assuntos
Corrida de Maratona , Fadiga Muscular , Músculo Esquelético , Sapatos , Vibração , Humanos , Masculino , Adulto , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Feminino , Corrida de Maratona/fisiologia , Pé/fisiologia , Dureza , Fenômenos Biomecânicos , Corrida/fisiologia , Pessoa de Meia-Idade
15.
J Food Sci ; 89(7): 4345-4358, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38853294

RESUMO

Freezing is a crucial step in the process of frozen foods. In this study, the effects of different freezing methods, including liquid nitrogen immersion freezing (LF), quick-freezing machine freezing (QF), packaging immersion freezing (PF), and ultralow temperature refrigerator freezing (UF), and freezing time (0, 15, 30, and 60 days) on the textural properties, dynamic rheological properties, water distribution, and structure of dough and the quality of end steamed bread were evaluated. Freezing resulted in a decline in the physicochemical properties of dough. UF- and QF-doughs had higher storage modulus and loss modulus, compared with PF- and LF-doughs. LF enhanced the textural attributes of the dough, resulting in reduced hardness and increased springiness. At 15 days of freezing, QF- and LF-doughs exhibited a compact and continuous structure with a smooth surface. Additionally, the correlation analysis elucidated that the weight loss rate and the bound water content of the dough had discernible impacts on the texture of both the dough and the resulting steamed bread. Overall, LF demonstrated a relatively high freezing efficiency and effectively maintained the quality of the dough for up to 15 days of freezing. These results offer valuable insights for the applications of freezing methods and time in frozen foods.


Assuntos
Pão , Farinha , Manipulação de Alimentos , Congelamento , Reologia , Pão/análise , Manipulação de Alimentos/métodos , Farinha/análise , Água/análise , Vapor , Dureza
16.
Clin Oral Investig ; 28(7): 402, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940942

RESUMO

OBJECTIVES: Evaluate the efficacy of denture cleaners on the adhesion of Candida albicans and their effects on the surface, optical, and mechanical properties of resins for conventional, milled, and 3D-printed denture bases. MATERIALS AND METHODS: A total of 240 resin samples were made, 120 for testing Candida albicans adhesion, optical stabilities (ΔE00), roughness (Ra), hydrophilicity (°), surface free energy (Owens-Wendt) and 120 samples for testing Candida albicans adhesion, surface microhardness (Knoop), flexural strength and modulus of elasticity in a three-point test, in which they were divided into 3 groups of denture resin (n = 40) and subdivided into 5 cleaners of dentures (n = 8). Data were evaluated by two-way ANOVA and Tukey's test for multiple comparisons (α = 0.05). RESULTS: Denture cleaners with an alkaline solution and dilute acid composition were those that showed the greatest effectiveness in reducing Candida albicans (P < 0.001), however 1% NaOCl significantly affected the properties of the resins (P < 0.05). Denture 3D-printed showed that the surface microhardness was significantly lower for all cleansers (P < 0.05). CONCLUSIONS: Listerine demonstrated superior efficacy in reducing Candida albicans with minimal effect on denture properties, whereas 1% NaOCl had a significant negative impact on the properties. The mechanical properties were significantly lower in 3D-printed resin than in other resins for all denture cleansers. CLINICAL RELEVANCE: Denture base materials are being sold to adapt to the CAD/CAM system, increasing the number of users of dentures manufactured with this system. Despite this, there is little investigation into denture cleaners regarding the adhesion capacity of microorganisms and the optical, surface and mechanical properties of dentures, thus requiring further investigation.


Assuntos
Candida albicans , Desenho Assistido por Computador , Bases de Dentadura , Higienizadores de Dentadura , Teste de Materiais , Impressão Tridimensional , Propriedades de Superfície , Candida albicans/efeitos dos fármacos , Bases de Dentadura/microbiologia , Higienizadores de Dentadura/farmacologia , Dureza , Resistência à Flexão , Materiais Dentários/química
17.
Food Res Int ; 190: 114587, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945567

RESUMO

The effect of 90, 180 and 270 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP) on the solubilisation of proteins and minerals and the rheological and textural properties of processed cheese (PC) prepared from Gouda cheese ripened for 30-150 d at 8°C was studied. The solubilisation of individual caseins and Ca and the maximum loss tangent during temperature sweeps of PC made from Gouda cheese increased, while hardness of PC decreased with ripening duration of the Gouda cheese. Levels of soluble Ca in PC increased with increasing concentration of TSC and SHMP, but decreased with increasing concentration of DSP. The solubilisation of casein and Ca due to ripening of Gouda cheese used for manufacturing PC could explain the changes in texture and loss tangent of PC. The results suggest that DSP, TSC or SHMP in PC formulation can form insoluble Ca-phosphate, soluble Ca-citrate or insoluble casein-Ca-HMP complexes, respectively, that influence casein solubilisation differently and together with levels of residual intact casein determine the functional attributes of PC.


Assuntos
Caseínas , Queijo , Manipulação de Alimentos , Reologia , Solubilidade , Queijo/análise , Manipulação de Alimentos/métodos , Caseínas/química , Citratos/química , Cálcio/análise , Cálcio/química , Fosfatos/análise , Fosfatos/química , Dureza , Fatores de Tempo , Fosfatos de Cálcio/química , Fosfatos de Cálcio/análise
18.
Food Res Int ; 190: 114553, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945595

RESUMO

Consumer preferences for walnut products are largely determined by the flavors released during mastication. In this study, a peeled walnut kernel (PWK) model was established with oral parameters decoupled using a Hutchings 3D model. The model explored in vitro variations using head-space solid-phase microextraction-gas chromatography-mass spectrometry and intelligent sensory techniques. The fracture strength, hardness, particle size, adhesiveness, springiness, gumminess, and chewiness were significantly reduced during mastication. We identified 61 volatile compounds and found that 2,5-dimethyl-3-ethylpyrazine is a key component, releasing predominantly baking and milky notes. Glutamic acid, alanine, arginine, and sucrose were identified as the key compounds in taste perception. The method can help establish a mastication model for nuts and facilitate breakthroughs in the development of walnut products and processing methods.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Juglans , Mastigação , Nozes , Paladar , Compostos Orgânicos Voláteis , Juglans/química , Nozes/química , Compostos Orgânicos Voláteis/análise , Humanos , Microextração em Fase Sólida , Dureza , Tamanho da Partícula , Aromatizantes/análise
19.
BMC Oral Health ; 24(1): 739, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937723

RESUMO

BACKGROUND: In dentistry, glass-ionomer cements (GICs) are extensively used for a range of applications. The unique properties of GIC include fluoride ion release and recharge, chemical bonding to the tooth's hard tissues, biocompatibility, a thermal expansion coefficient like that of enamel and dentin, and acceptable aesthetics. Their high solubility and poor mechanical qualities are among their limitations. E-glass fibers are generally utilized to reinforce the polymer matrix and are identified by their higher silica content. OBJECTIVES: The purpose of the study was to assess the impact of adding (10 wt% and 20 wt%) silane-treated E-glass fibers to traditional GIC on its mechanical properties (compressive strength, flexural strength, and surface hardness) and solubility. METHODS: The characterization of the E-glass fiber fillers was achieved by XRF, SEM, and PSD. The specimens were prepared by adding the E-glass fiber fillers to the traditional GIC at 10% and 20% by weight, forming two innovative groups, and compared with the unmodified GIC (control group). The physical properties (film thickness and initial setting time) were examined to confirm operability after mixing. The evaluation of the reinforced GIC was performed by assessing the compressive strength, flexural strength, hardness, and solubility (n = 10 specimens per test). A one-way ANOVA and Tukey tests were performed for statistical analysis (p ≤ 0.05). RESULTS: The traditional GIC showed the least compressive strength, flexural strength, hardness, and highest solubility. While the GIC reinforced with 20 wt% E-glass fibers showed the highest compressive strength, flexural strength, hardness, and least solubility. Meanwhile, GIC reinforced with 10 wt% showed intermediate results (P ≤ 0.05). CONCLUSION: Using 20 wt% E-glass fiber as a filler with the traditional GIC provides a strengthening effect and reduced solubility.


Assuntos
Força Compressiva , Resistência à Flexão , Cimentos de Ionômeros de Vidro , Vidro , Dureza , Teste de Materiais , Solubilidade , Cimentos de Ionômeros de Vidro/química , Vidro/química , Propriedades de Superfície , Silanos/química , Microscopia Eletrônica de Varredura , Análise do Estresse Dentário , Maleabilidade , Humanos
20.
BMC Oral Health ; 24(1): 713, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902666

RESUMO

BACKGROUND: Low mechanical properties are the main limitation of glass ionomer cements (GICs). The incorporation of elastomeric micelles is expected to enhance the strength of GICs without detrimentally affecting their physical properties and biocompatibility. This study compared the chemical and mechanical properties, as well as the cytotoxicity, of elastomeric micelles-containing glass ionomer cement (DeltaFil, DT) with commonly used materials, including EQUIA Forte Fil (EF), Fuji IX GP Extra (F9), and Ketac Molar (KT). METHOD: Powder particles of GICs were examined with SEM-EDX. Setting kinetics were assessed using ATR-FTIR. Biaxial flexural strength/modulus and Vickers surface microhardness were measured after immersion in water for 24 h and 4 weeks. The release of F, Al, Sr, and P in water over 8 weeks was analyzed using a fluoride-specific electrode and ICP-OES. The toxicity of the material extract on mouse fibroblasts was also evaluated. RESULTS: High fluoride levels in the powder were detected with EF and F9. DT demonstrated an initial delay followed by a faster acid reaction compared to other cements, suggesting an improved snap set. DT also exhibited superior flexural strength than other materials at both 24 h and 4 weeks but lower surface microhardness (p < 0.05). EF and F9 showed higher release of F, Al, and P than DT and KT. There was no statistically significant difference in fibroblast viability among the tested materials (p > 0.05). CONCLUSIONS: Elastomeric micelles-containing glass ionomer cement (DT) exhibited satisfactory mechanical properties and cytocompatibility compared with other materials. DT could, therefore, potentially be considered an alternative high-strength GIC for load-bearing restorations.


Assuntos
Elastômeros , Fibroblastos , Resistência à Flexão , Cimentos de Ionômeros de Vidro , Dureza , Teste de Materiais , Micelas , Cimentos de Ionômeros de Vidro/toxicidade , Cimentos de Ionômeros de Vidro/química , Animais , Camundongos , Fibroblastos/efeitos dos fármacos , Elastômeros/química , Elastômeros/toxicidade , Alumínio/química , Fluoretos/química , Estrôncio/química , Cimento de Policarboxilato/química , Cimento de Policarboxilato/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Maleabilidade , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Fatores de Tempo , Materiais Biocompatíveis/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA