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O avanço tecnológico revolucionou a prática odontológica, com os alinhadores ortodônticos emergindo como uma escolha altamente popular entre pacientes que buscam tratamentos estéticos e confortáveis. No entanto, apesar de sua crescente demanda, permanecem questões cruciais relacionadas à eficácia e análise dimensional desses dispositivos. Este artigo oferece uma análise abrangente das características químicas, físicas e mecânicas dos alinhadores ortodônticos, iluminando a influência vital do processo de termoformação e da espessura nas propriedades desses materiais. Compreender profundamente essas características é essencial para aprimorar a eficácia e a durabilidade dos alinhadores ortodônticos, contribuindo, assim, para o sucesso e a evolução dos tratamentos ortodônticos modernos. Neste estudo, exploraremos: 1) as propriedades químicas dos materiais e como elas afetam a biocompatibilidade e a resistência à degradação; 2) as características físicas, incluindo textura de superfície, transparência e sua influência na adaptação bucal e no conforto do paciente; 3) as propriedades mecânicas, como flexibilidade e rigidez, e como essas características afetam a distribuição de forças de movimentação dentária; 4) a influência do processo de termoformação na precisão e reprodutibilidade dos alinhadores, bem como sua relação com a qualidade do tratamento; 5) a análise crítica da espessura dos alinhadores e seu papel na capacidade de aplicar forças adequadas para a movimentação dentária. Ao abordar esses aspectos, este artigo visa oferecer uma visão holística das complexidades envolvidas na fabricação e uso de alinhadores ortodônticos. Esperamos que esta revisão contribua para uma compreensão mais profunda desses dispositivos e promova avanços significativos na ortodontia, beneficiando tanto os profissionais quanto os pacientes.

Technological advancement has revolutionized dental practice, with orthodontic aligners emerging as a trendy choice among patients seeking aesthetic and comfortable treatments. However, despite their growing demand, crucial questions remain regarding these devices' effectiveness and dimensional analysis. This article offers a comprehensive analysis of the chemical, physical, and mechanical characteristics of orthodontic aligners, illuminating the vital influence of the thermoforming process and thickness on the properties of these materials. Understanding these characteristics in depth is essential to improving the effectiveness and durability of orthodontic aligners, thus contributing to the success and evolution of modern orthodontic treatments. In this study, we will explore 1) the chemical properties of materials and how these properties affect biocompatibility and resistance to degradation; 2) the physical characteristics, including surface texture, transparency and their influence on oral adaptation and patient comfort; 3) mechanical properties, such as flexibility and stiffness, and how these characteristics affect the distribution of tooth movement forces; 4) the influence of the thermoforming process on the precision and reproducibility of the aligners, as well as its relationship with the quality of the treatment; 5) critical analysis of aligner thickness and its role in the ability to apply adequate forces for tooth movement. By addressing these aspects, this article aims to offer a holistic view of the complexities involved in manufacturing and using orthodontic aligners. We hope this review will contribute to a deeper understanding of these devices and promote significant advances in orthodontics, benefiting professionals and patients.

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OBJECTIVE: Analyze the effects of the functionalization of pre-functionalized GIC particles with chlorhexidine on the physicochemical properties and antimicrobial activity. MATERIALS AND METHODS: Four groups were prepared: (1) GIC (Bioglass R - Biodinamica) - control group; (2) GIC-CHX 1%: Group containing 1% pre-reacted CHX particles; (3) GIC-CHX 2.5%: Group containing 2.5% pre-reacted CHX particles; (4) GIC-CHX 5%: Group containing 5% pre-reacted CHX particles. Hourglass-shaped specimens (10 mm × 2 mm x 1 mm) were fabricated for mechanical tests including cohesive strength (n = 12), modulus of elasticity (n = 12) and microhardness (n = 10). Discs (10 mm × 2 mm) were prepared for the analysis of Ca+2, PO4- and F- ions release (n = 3), and roughness (n = 12). To evaluate the setting time, a Gilmore needle was used according to ISO 9917-1:2016. Disk-shaped specimens (5 × 1mm) were manufactured and subjected to bacterial activity (n = 9) (Streptococcus mutans ATCC 159). RESULTS: Modulus, roughness, setting time and ions release (Ca+2, PO4-, and F-) there were no statistically significant differences among the groups (p > 0.05). The setting time did not change with the incorporation of CHX. The GIC-CHX 2.5% and GIC-CHX 5% groups exhibited superior antibacterial activity compared to the control group and GIC-CHX 1% (p < 0.001). The GIC-CHX 5% group showed the highest microhardness values (p < 0.041), cohesive strength (p < 0.009) when compared to the control group. CONCLUSION: The pre-reacted CHX in GICs was able to confer antimicrobial activity, improve cohesive strength, microhardness, and did not impair ion release, setting time, and roughness.

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The present study examined different concentrations of the butylated hydroxytoluene (BHT) inhibitor on the kinetics of conversion, polymerization shrinkage stress, and other correlated physicochemical properties of experimental resin composites (ERC). A model composite was formulated with 75 wt% filler containing 0.5 wt% camphorquinone and 1 wt% amine with BHT concentrations of 0.01 wt% (BHT-0.01); 0.1 wt% (BHT-0.1); 0.25 wt% (BHT-0.25); 0.5 wt% (BHT-0.5); 1 wt% (BHT-1), and control (no BHT). They were tested on polymerization shrinkage stress (PSS; n = 5), degree of conversion (DC; n = 3), maximum polymerization rate (RpMAX; n = 5), water sorption (Wsp; n = 0), and solubility (Wsl; n = 10), flexural strength (FS; n = 10), flexural modulus (FM; n = 10), Knoop microhardness (KH; n = 10), and microhardness reduction (HR; n = 10). Data concerning these tests were submitted to one-way ANOVA and Tukey's test (α = 0.05; ß = 0.2). BHT-0.25, BHT-0.5, and BHT-1 showed a gradually significant decrease in PSS (p = 0.037); however, BHT-1 demonstrated a decrease in the physicochemical properties tested. Thus, within the limitations of this study, it was possible to conclude that BHT concentrations between 0.25 and 0.5 wt% are optimal for reducing shrinkage stress without affecting other physicochemical properties of ERCs.

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OBJECTIVE: To evaluate experimental dimethacrylate-based materials containing calcium orthophosphates or calcium silicate particles in terms of their optical, mechanical and Ca2+ release behaviour. METHODS: Dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HAp), beta-tricalcium phosphate (ß-TCP) or calcium silicate (CaSi) particles were added to a photocurable BisGMA/TEGDMA resin (1:1 in mols) at a 30 vol% fraction. Materials containing silanized or non-silanized barium glass particles were used as controls. Degree of conversion (DC) at the top and base of 2-mm thick specimens was determined by ATR-FTIR spectroscopy (n = 5). Translucency parameter (TP) and transmittance (%T) were determined using a spectrophotometer (n = 3). Biaxial flexural strength (BFS) and flexural modulus (FM) were determined by biaxial flexural testing after 24 h storage in water (n = 10). Ca2+ release in water was determined during 28 days by inductively coupled plasma optical emission spectrometry (n = 3). Statistical analysis was performed using ANOVA/Tukey test (DC: two-way; TP, %T; BFS and FM: one-way; Ca2+ release: repeated measures two-way, α = 5 %). RESULTS: CaSi and ß-TCP particles drastically reduced DC at 2 mm, TP and %T (p < 0.001). Compared to both controls, all Ca2+-releasing materials presented lower BFS (p < 0.001) and only the material with DCPD showed significantly lower FM (p < 0.05). The material containing CaSi presented the highest Ca2+ release, while among materials formulated with calcium orthophosphates the use of DCPD resulted in the highest release (p < 0.001). SIGNIFICANCE: CaSi particles allowed the highest Ca2+ release. Notwithstanding, the use of DCPD resulted in a material with the best compromise between optical behaviour, DC, strength and Ca2+ release.

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The obtained seeds from fruit processing are considered by-products containing proteins that could be utilized as ingredients in food manufacturing. However, in the specific case of soursop seeds, their usage for the preparation of protein isolates is limited. In this investigation a protein isolate from soursop seeds (SSPI) was obtained by alkaline extraction and isoelectric precipitation methods. The SSPI was sonicated at 200, 400 and 600 W during 15 and 30 min and its effect on the physicochemical, functional, biochemical, and structural properties was evaluated. Ultrasound increased (p < 0.05) up to 5 % protein content, 261 % protein solubility, 60.7 % foaming capacity, 30.2 % foaming stability, 86 % emulsifying activity index, 4.1 % emulsifying stability index, 85.4 % in vitro protein digestibility, 423.4 % albumin content, 83 % total sulfhydryl content, 316 % free sulfhydryl content, 236 % α-helix, 46 % ß-sheet, and 43 % ß-turn of SSPI, in comparison with the control treatment without ultrasound. Furthermore, ultrasound decreased (p < 0.05) up to 50 % particle size, 37 % molecular flexibility, 68 % surface hydrophobicity, 41 % intrinsic florescence spectrum, and 60 % random coil content. Scanning electron microscopy analysis revealed smooth structures of the SSPI with molecular weights ranging from 12 kDa to 65 kDa. The increase of albumins content in the SSPI by ultrasound was highly correlated (r = 0.962; p < 0.01) with the protein solubility. Improving the physicochemical, functional, biochemical and structural properties of SSPI by ultrasound could contribute to its utilization as ingredient in food industry.

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Los vidrios bioactivos (VBa) son materiales biocerámicos que tienen una extensa aplicación en medicina y odontología. A causa de su contenido de calcio y fosfato son muy simi- lares a la hidroxiapatita del tejido óseo. Su biocompatibili- dad y bioactividad los hacen materiales muy útiles para ser aplicados en diferentes áreas de la práctica dental, tales como periodoncia, cirugía, odontología restauradora y endodoncia. En endodoncia los VBa están indicados para realizar protec- ciones pulpares directas, pulpotomías, desinfecciones y obtu- raciones del sistema de conductos radiculares. El objetivo del presente trabajo fue realizar una revisión de las propiedades biológicas de los VBa en relación a sus aplicaciones en en- dodoncia (AU)

Bioactive glasses (BGs) are bioceramic materials with extensive clinical applications in medicine and dentistry. Be- cause of their phosphate and calcium contents, they are like the hydroxyapatiteof bone tissue. Their biocompatibility and bioactivity make them very useful biomaterials in different areas of dental practice, such as periodontics, oral surgery, restorative dentistry, and endodontics. In endodontics, bioac- tive glasses are indicated for direct pulp capping, pulpoto- mies, disinfections and fillings of the root canal system. The aim of this work was to carry out a review of the biological properties of BGs in relation to its application in endodontics (AU)

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This work aimed to characterize and compare the physicochemical properties of four pulse starches: bean, chickpea, lentil, and pea. Chemical proximate analysis, elemental composition, morphological grain characterization, crystalline structure, thermal analysis, FTIR analysis, and pasting properties were conducted. The proximate analysis shows that these starches have low fat, mineral, and protein content but high amylose values ranging from 29 to 36 % determined by colorimetry. Despite the high amylose content, the starches did not exhibit the typical behavior of an amylose-rich starch, with high peak viscosity and low breakdown and setback. It was found that this behavior was likely due to the large granule size of the ellipsoidal, spherical, and kidney-shaped granules and the high content of some minerals such as Na, Mg, K, Fe, Mn, P, and Si. The study also found that all pulse starches simultaneously contain monoclinic and hexagonal crystals, making them C-type starches. The findings were verified through the Rietveld analyses of X-ray diffraction patterns and differential scanning calorimetry, in which bimodal endothermic peaks evidenced both types of crystals being gelatinized.

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This research investigated the impact of ohmic heating (OH) on the physicochemical properties and resistant starch formation in native corn starch. Electric field strengths (EFS) of 50, 75, and 100 V/cm were applied to native starch, at a starch-water ratio of 1:1 w/v. The conductivity of the medium is a crucial factor in ohmic heating. In this study, the conductivity values at 120 °C were measured at 1.5 mS/m. The study revealed two distinct outcomes resulting from the application of different EFS. Firstly, a thermal effect induced gelatinization, resulting in a reduction in the enthalpy of corn starch, an increase in the water absorption index (WAI) and the water solubility index (WSI), and a decrease in peak viscosity. Secondly, a non-thermal effect of OH was observed, leading to the electrolysis of certain starch compounds and water. This electrolysis process generated radicals (-OH) that interacted with starch components, augmenting the percentage of resistant starch. This increase was associated with elevated levels of carbonyl and carboxyl groups at 75 and 100 V/cm.

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This study analyzed and compared the physicochemical and mechanical properties of preheated resin composite with light-cured resin cement for luting indirect restorations. 210 specimens of resin cement/resin composite were prepared according to preheating treatment heated (Htd) or not (NHtd). Light-cured resin cement (Variolink Veneer, Ivoclar), and resin composite (Microhybrid-Z100, 3 M; Nanohybrid-Empress direct, Ivoclar; and Bulk fill-Filtek One, 3 M) were used (n = 10). Resin cement specimens were not preheated. The response variables were (n = 10): film thickness, microhardness, liquid sorption and solubility. Data were analyzed by 2-way ANOVA and Tukey HSD post-test (α = 0.05). Bulk fill NHtd resin had the highest film thickness values (p < 0.001). Microhybrid and nanohybrid Htd resins had the smallest thicknesses and did not differ from the cement (p > 0.05). The highest microhardness values were found for Bulk fill NHtd and Bulk fill Htd resins. The nanohybrid and microhybrid Htd resins showed the lowest microhardness values, with no difference in cement (p > 0.05). For liquid sorption, there was no significant difference between the groups (p = 0.1941). The microhybrid Htd resin showed higher solubility values than the other materials (p = 0.0023), but it did not differ statistically from resin cement (p > 0.05). Preheating composite resins reduced the film thickness. After heating, nanohybrid and Bulk fill resins retained stable microhardness, sorption, and solubility values.

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Banana starch has a highly resistant starch (RS) and slow-digested starch (SDS) content, making it attractive as a functional ingredient. Unfortunately, banana starch requires modification processes due to the loss of RS and SDS during gelatinization because of its thermolabile characteristics. This study explores the effect of banana starch modification by enzymatic, heat moisture treatment (HMT) and dual modification (HMT+ enzymatic) on its nutritional (RS, SDS) and functional properties (hydration, structural, gelation, rheological). HMT and dual modifications decrease RS (from 44.62 g/100 g to 16.62 and 26.66 g/100 g, respectively) and increase SDS (from 21.72 g/100 g to 33.91 and 26.95 g/100 g, respectively) in raw starch but induce structural changes that enhance RS (from 3.10 g/100 g to 3.94 and 4.4 g/100 g, respectively) and SDS (from 2.58 g/100 g to 9.58 and 11.48 g/100 g) thermo-resistance in gelled starch. Also, changes in the functional properties of starches were evidenced, such as weaker gels (hardness < 41 g), lower water absorption (<12.35 g/g), high starch solubility (>1.77 g/100 g) and increased gelatinization temperature. Improved gelatinization temperature and RS thermostability resulted from modifications that could expand banana starch applications as a beverage and compote thickener agent.

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