RESUMEN

The aim of this study was to develop a mixture of dimethacrylate isomers (PG6EMA) as a potential monomer for dental adhesives and composites. PG6EMA was synthesized de novo and characterized in the presence of ethanol (3%, 6% or 9%). BisGMA/TEGDMA (BTEG, 50/50 wt.%) was used as the resin control. Composites were formulated with 60 wt.% of either PG6EMA or BisGMA (40 wt.% TEGDMA and 70 wt.% filler). DMPA (0.2 wt.%) and DPI-PF6 (0.4 wt.%) were added as photoinitiators, irradiated with a mercury arc lamp (320-500 nm, 500 mW/cm2; Acticure). All materials were tested for polymerization kinetics (near-infrared), viscosity (η) and storage modulus (G', oscillatory rheometry). The composites were further characterized for water sorption/solubility, wet/dry flexural strength/modulus and polymerization stress. Data were analyzed with one-way ANOVA/Tukey's test (α = 0.05). The PG6EMA resins showed lower rates of polymerization compared with BTEG (p = 0.001) but high degrees of conversion (p = 0.002). Solvent concentration did not affect RPMAX but the 6% and 9% mixtures showed higher final DC, likely due to reduced viscosity. PG6EMA had much higher viscosity than BTEG (p <0.001) and lower G' (p = 0.003). Composites modified with PG6EMA have slower polymerization rates (p = 0.001) but higher final DC (p = 0.04) than the control. PG6EMA/TEGDMA showed lower dry/wet flexural strength and comparable dry modulus. The PG6EMA/TEGDMA composite showed a 18.4% polymerization stress reduction compared to the BTEG composite. Both base monomers had similar WS/SL and G'. Within its limitations, this study demonstrated that the newly synthesized PG6EMA was a viable alternative to BisGMA in dental composites.

Asunto(s)

Bisfenol A Glicidil Metacrilato , Resinas Compuestas , Ensayo de Materiales , Metacrilatos , Polimerizacion , Ácidos Polimetacrílicos , Resinas Compuestas/química , Resinas Compuestas/efectos de la radiación , Bisfenol A Glicidil Metacrilato/química , Metacrilatos/química , Viscosidad , Ácidos Polimetacrílicos/química , Análisis de Varianza , Factores de Tiempo , Reproducibilidad de los Resultados , Valores de Referencia , Resistencia Flexional , Polietilenglicoles/química , Propiedades de Superficie , Solubilidad , Cinética , Reología , Cementos Dentales/química , Curación por Luz de Adhesivos Dentales/métodos

RESUMEN

OBJECTIVES: To analyze the incorporation of cardanol trimethacrylate monomer (CTMA), derived from the cashew nut shell liquid, as a substitute for Bis-GMA in acrylic resins formulations and its effect on experimental resin composites' physicochemical and mechanical properties. MATERIALS AND METHODS: The intermediary cardanol epoxy was synthesized via cardanol epoxidation, followed by the synthesis of CTMA through methacrylic anhydride solvent-free esterification. Experimental resin composites were formulated with an organic matrix composed of Bis-GMA/TEGDMA (50/50 wt %) (control). CTMA was gradually added to replace different proportions of Bis-GMA: 10 wt % (CTMA-10), 20 wt % (CTMA-20), 40 wt % (CTMA-40), and 50 wt % (CTMA-50). The composites were characterized by degree of conversion, water sorption and solubility, viscosity, thermogravimetric analysis, dynamic mechanical analysis, flexural strength and elastic modulus. Data were analyzed with one-way ANOVA and Tukey's post-hoc test (α = 0.05), except for water sorption data, which were analyzed by Kruskall-Wallis and Dunn's method. RESULTS: CTMA-based and control composites did not show statistically significant differences regarding degree of conversion, flexural strength and elastic modulus. CTMA reduced the viscosity and solubility compared to the Bis-GMA-based composite. The CTMA-40 and CTMA-50 exhibited significantly lower water sorption compared to the control. Also, acceptable thermal stability and viscoelastic properties were obtained for safe use in the oral cavity. CONCLUSIONS: Incorporating CTMA into composites resulted in similar chemical and mechanical properties compared to Bis-GMA-based material while reducing viscosity, water sorption and solubility. CLINICAL RELEVANCE: CTMA could be used as a trimethacrylate monomer replacing Bis-GMA in resin composites, thereby minimizing BPA exposure.

Asunto(s)

Bisfenol A Glicidil Metacrilato , Resinas Compuestas , Resistencia Flexional , Ensayo de Materiales , Fenoles , Ácidos Polimetacrílicos , Solubilidad , Resinas Compuestas/química , Bisfenol A Glicidil Metacrilato/química , Fenoles/química , Viscosidad , Ácidos Polimetacrílicos/química , Módulo de Elasticidad , Metacrilatos/química , Termogravimetría , Polietilenglicoles/química , Anacardium/química

RESUMEN

The awareness of molar incisor hypomineralisation (MIH) has led to its increased clinical detection, consequently drawing more attention to its associated complications. This text offers an overview of the esthetic management of anterior teeth affected by MIH, a condition characterized by enamel defects that present significant cosmetic challenges. The focus is on the clinical presentation of MIH characteristics, considering the depth of lesions and the clinical aspects, and the treatment protocols available, despite a lack of extensive scientific evidence. To the best of the current scientific knowledge, the text evaluates the potential of minimally invasive procedures, as well as the use of traditional composite resin techniques and their possible combinations, highlighting the critical role of esthetic considerations for the impacted anterior teeth. The chapter is augmented with five illustrative clinical cases that display the practical application of these treatment approaches. These examples articulate the clinical decision-making process and personalized restorative strategies, aiming to balance function with enhanced esthetic results. The described cases act as a roadmap for clinicians tackling the complexities of MIH treatment in the context of limited empirical evidence, providing insights into achieving both satisfactory and esthetically pleasing outcomes for patients suffering from this condition.

Asunto(s)

Hipoplasia del Esmalte Dental , Estética Dental , Incisivo , Humanos , Hipoplasia del Esmalte Dental/terapia , Incisivo/patología , Femenino , Restauración Dental Permanente/métodos , Masculino , Resinas Compuestas , Adulto , Hipomineralización Molar

RESUMEN

OBJECTIVE: To evaluate the color change (ΔE) and fluorescence (FL) of resin composites after the consumption of beverages. MATERIALS AND METHODS: One hundred and sixty disc-shaped specimens (6 × 2 mm) of Filtek Z350 XT (FZX) and Forma (FOR) resin composites were randomized for use in devices by five volunteers who ingested 100 ml daily of red wine (RW), beer (BE), energy drink (ED) and water (WT) over 15 days. The data were collected from digital photographs and analyzed using the CIE-Lab and RGB scales to obtain ΔE and FL and statistics via two-way ANOVA (for ΔE) and ANOVA for repeated measures (for FL), α = 0.05. RESULTS: The highest ΔE values were obtained for FZX and FOR in the RW (ΔE = 10.5 for FZX and ΔE = 9.90 for FOR) and BE (ΔE = 6.3 for FZX and ΔE = 6.1 for FOR) drinks. For FL, there were different levels of change between the composites, with a much more significant reduction in FL intensity with RW. CONCLUSION: Beverages have the potential to stain the composites evaluated, especially alcoholic beverages. CLINICAL SIGNIFICANCE: Before carrying out an esthetic treatment with resin composites, it is ideal to investigate the types of drinks consumed by patients, for greater predictability of treatment.

Asunto(s)

Color , Resinas Compuestas , Vino , Resinas Compuestas/química , Humanos , Fluorescencia , Adulto , Bebidas Energéticas/análisis , Ensayo de Materiales , Cerveza , Bebidas , Femenino , Masculino , Propiedades de Superficie

RESUMEN

OBJECTIVE: this study sought to evaluate the effect of isobornyl methacrylate (IBOMA) as a diluent monomer on the physicochemical properties of experimental flowable resin composites. METHODOLOGY: the organic resin matrix of a modal flowable resin composite was formulated with 50 wt.% of bisphenol-A-glycidyl methacrylate (Bis-GMA) and 50 wt.% of a diluent monomer, in which IBOMA was used as a combining or substituent diluent monomer to triethylene glycol dimethacrylate (TEGDMA). The resin matrices were filled with 55 wt.% particles, of which 10 wt.% was 0.05-µm fumed silica, and 45 wt.% was 0.7-µm BaBSiO2 glass. Polymerization shrinkage stress (PSS; n=10), degree of conversion (DC; n=3), maximum rate of polymerization (Rpmax; n=3), film thickness (FT; n=10), sorption (Wsp; n=10), solubility (Wsl; n=10), flexural strength (FS; n=10), flexural modulus (FM; n=10), Knoop microhardness (KH; n=10), and microhardness reduction after chemical softening (HR; n=10) were evaluated. Data were analyzed using one-way ANOVA, followed by Tukey's test (α=0.05; ß=0.2). RESULTS: the results showed that the substitution or addition of IBOMA reduced FT (p=0.001), PSS (p=0.013), Rpmax (p=0.001), DC (p=0.001), FM (p=0.006) Wsp (p=0.032), and Wsl (p=0.021). However, when used as a complete substituent, IBOMA demonstrated significantly lower FS (p=0.017) and KH (p=0.008), while TEGDMA demonstrated significantly lower HR (p=0.022). CONCLUSION: the flowable composite containing IBOMA combined with TEGDMA showed no effect in KH and FS and effectively reduced the PSS, RP, FT, Wsp, and Wsl. However, it showed a reduction in DC, FS, and an increase in HR.

Asunto(s)

Bisfenol A Glicidil Metacrilato , Resinas Compuestas , Resistencia Flexional , Ensayo de Materiales , Metacrilatos , Polietilenglicoles , Polimerizacion , Ácidos Polimetacrílicos , Solubilidad , Propiedades de Superficie , Resinas Compuestas/química , Metacrilatos/química , Ácidos Polimetacrílicos/química , Polietilenglicoles/química , Bisfenol A Glicidil Metacrilato/química , Análisis de Varianza , Reproducibilidad de los Resultados , Valores de Referencia , Factores de Tiempo , Pruebas de Dureza , Dióxido de Silicio/química

RESUMEN

This study aimed to evaluate the masking ability of different resin composite (RC) layering techniques over discolored substrates. Layering strategies were tested (n=10), using different RCs: flowable opaque, white dentin, A1 dentin, A1 body, and A1 enamel (Filtek Z350XT; 3M ESPE). Bilayer and trilayer RC combinations resulted in final thicknesses of 1 mm, 1.5 mm, and 2 mm. Substrates tested were: A1 (reference), A3, A4, B3, C2, and C4 (Filtek Z350XT Dentin; 3M ESPE). Color differences (∆E00) were measured for the RC layers over discolored substrates with the CIEDE2000 formula. The results were compared statistically (One-way ANOVA) and descriptively (acceptability=1.77 and perceptibility=0.81 thresholds). The layering strategy influenced the ∆E00 of RCs over all substrates (P<0.001). The 1 mm bilayer group combining 0.5 mm of dentin and 0.5 mm of enamel led to ∆E00 below AT for substrates A3 and B3; the 1.5 mm bilayer group combining A1 dentin (1 mm) and enamel (0.5 mm) provided ∆E00 below AT for substrates A3, A4, and C2 and ∆E00 below PT for B3; for substrate C4, the 2 mm trilayer group combining flowable opaque (0.2 mm), A1 dentin (1.3 mm) and enamel (0.5 mm) provided ∆E00 below PT, and the 1.5 mm trilayer groups (flowable opaque + 0.8 mm dentin or body + enamel) led to ∆E00 below AT. Resin Composites were effective in masking discolored substrates. The most adequate layering strategy depended on substrate shade.

Asunto(s)

Resinas Compuestas , Resinas Compuestas/química , Color , Humanos , Ensayo de Materiales , Propiedades de Superficie , Esmalte Dental , Dentina

RESUMEN

Introdução:Na odontologia moderna, a estética vem ocupando um espaço cada vez mais expressivo, e o desejo por dentes mais brancos, a insatisfação com o alinhamento dos dentes e com a anatomia dentária, têm sido os motivos mais relevantes de procura dos pacientes nos consultórios odontológicos.Objetivo:O presente artigo tem como objetivo descrever, através de relato de caso clínico, uma abordagem terapêutica estética e conservadora para fechamento de múltiplos diastemas anterossuperiores com a utilização de facetas de resina composta.Relato de caso:Paciente do sexo masculino, 21 anos de idade, procurou atendimento queixando-se de insatisfação estética pelos diastemas apresentados. Por meio de um planejamento digital das facetas em resina, com mockup e modelo impresso em 3D, as restaurações foram feitas respeitando anatomia, forma, opacidade e cores dos dentes naturais do paciente. O resultado dos procedimentos adotados foi satisfatório, demonstrando que a técnica empregada foi eficaz, sendo capaz de devolver um sorriso estético e biológico ao paciente. A odontologia contemporânea tem ofertado cada vez mais materiais com capacidade de devolver estética e função em dentes de forma minimamente invasivas, além de passar total confiabilidade em tratamentos a longo prazo, agradando o paciente desde a apresentação digital do planejamento traçado pelo cirurgião dentista com previsibilidade dos resultados, até o momento final do tratamento.Conclusões:O recontorno estético com resina composta representa uma opção funcional e de baixo custo para o tratamento de pacientes que apresentam diastemas múltiplos, principalmente em pacientes jovens pela preservação daestrutura dentária e possibilidade de reparo, sendo considerado um procedimento reversível, rápido e de baixo custo (AU).

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Introduction:Aesthetics have been occupying an increasingly significant role in modern dentistry, and the desire for whiter teeth, dissatisfaction with tooth alignment, and dental anatomy concerns have been the most relevant reasons for patients seeking dental care. Objective:This article aims to describe an aesthetic and conservative therapeutic approach for closing multiple anterior upper diastemas using composite resin veneers in a clinical case report. Case report:A 21-year-old male patient sought treatment, expressing dissatisfaction with the diastemas he had. The restorations were performed using digital planning of the resin veneers with a mockup and a 3D-printed model, while respecting the patient's natural tooth anatomy, shape, opacity, and colors. The results of the adopted procedures were satisfactory, demonstrating effectiveness of the employed technique in restoring an aesthetic and biologically harmonious smile to the patient. Contemporary dentistry has been offering increasingly more materials capable of providing aesthetics and function to teeth through minimally invasive approaches. This not only ensures long-term treatment reliability, but also pleases the patient with a digital presentation of the treatment plan outlined by the dentist, predicting the results up to the final stages of the treatment. Conclusions:Aesthetic contouring using composite resin presents a functional and cost-effective option for treating patients with multiple diastemas, especially among young patients due to its preservation of dental structure, repair potential, and being considered a reversible, fast, and low-cost procedure (AU).

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Introducción: En la odontología moderna, la estética viene ocupando un espacio cada vez más destacado, y las ganas de tener dientes más blancos, la insatisfacción con el alineamiento de los dientes, y la anatomía dental son las razonesmás relevantes por las cuales los pacientes acuden a las consultas odontológicas. Objetivo:El presente artículo tiene como objetivo describir, a través de un relato de caso clínico, un abordaje terapéutico estético y conservador para el cierre de múltiples diastemas anterosuperiores mediante el uso de carillas de resina compuesta. Informe de caso:Paciente del sexo masculino, 21 años de edad, buscó atendimiento quejándose de insatisfacción estética debido a los diastemas presentados. A través de una planificación digital de las carillas en resina, con un mockup y un modelo impreso en 3D, las restauraciones fueron ejecutadas, respetándose la anatomía, forma, opacidad y colores de los dientes naturales del paciente. El resultado de los procedimientos adoptados fue satisfactorio y demostró que la técnica utilizada fue eficaz, siendo capaz de restituir una sonrisa estética y funcional al paciente. La odontología contemporánea viene ofreciendo cada vez más materiales con la capacidad de devolver estética y función a los dientes de maneras mínimamente invasivas, además de brindar total confiabilidad en tratamientos a largo plazo, satisfaciendo al paciente desde la presentación digital del plan trazado por el cirujano dentista con la previsibilidad de los resultados, hasta el momento final del tratamiento. Conclusiones:El recontorneado estético con resina compuesta representa una opción funcional y de bajo costo para el tratamiento de pacientes con múltiples diastemas, especialmente en pacientes jóvenes, debido a la preservación de la estructura dental y la posibilidad de reparación. Se considera, de este modo, que se trata de un procedimiento reversible, rápido y económico (AU).

Asunto(s)

Humanos , Masculino , Adulto , Resinas Compuestas/química , Coronas con Frente Estético , Diastema/terapia , Estética Dental , Procedimientos Quirúrgicos Mínimamente Invasivos

RESUMEN

OBJECTIVE: To formulate an experimental methacrylate-based photo-polymerizable resin for 3D printing with ytterbium trifluoride as filler and to evaluate the mechanical, physicochemical, and biological properties. METHODS: Resin matrix was formulated with 60 wt% UDMA, 40 wt% TEGDMA, 1 wt% TPO, and 0.01 wt% BHT. Ytterbium Trifluoride was added in concentrations of 1 (G1 %), 2 (G2 %), 3 (G3 %), 4 (G4 %), and 5 (G5 %) wt%. One group remained without filler addition as control (GC). The samples were designed in 3D builder software and printed using a UV-DLP 3D printer. The samples were ultrasonicated with isopropanol and UV cured for 60 min. The resins were tested for degree of conversion (DC), flexural strength, Knoop microhardness, softening in solvent, radiopacity, colorimetric analysis, and cytotoxicity (MTT and SRB). RESULTS: Post-polymerization increased the degree of conversion of all groups (p < 0.05). G2 % showed the highest DC after post-polymerization. G2 % showed no differences in flexural strength from the G1 % and GC (p > 0.05). All groups showed a hardness reduction after solvent immersion. No statistical difference was found in radiopacity, softening in solvent (ΔKHN%), colorimetric spectrophotometry, and cytotoxicity (MTT) (p > 0.05). G1 % showed reduced cell viability for SRB assay (p < 0.05). SIGNIFICANCE: It was possible to produce an experimental photo-polymerizable 3D printable resin with the addition of 2 % ytterbium trifluoride as filler without compromising the mechanical, physicochemical, and biological properties, comparable to the current provisional materials.

Asunto(s)

Dureza , Ensayo de Materiales , Metacrilatos , Impresión Tridimensional , Metacrilatos/química , Resistencia Flexional , Polimerizacion , Polietilenglicoles/química , Resinas Compuestas/química , Ácidos Polimetacrílicos/química , Poliuretanos/química , Colorimetría , Propiedades de Superficie

RESUMEN

This in vitro study aimed to evaluate the repair bond strength of resin-modified glass ionomer cement using either the same material or a universal adhesive in the etch-and-rinse and self-etch modes plus resin composite. Twenty-four resin-modified glass ionomer cement blocks were stored in distilled water for 14 d and thermocycled. Sandpaper ground specimens were randomly assigned to three experimental groups according to the repair protocol: resin-modified glass ionomer cement (Riva Light Cure, SDI) and universal adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in etch-and-rinse or self-etch modes and nanohybrid resin composite (Z350 XT, 3M Oral Care). After 24 h of water storage, the blocks were sectioned, and bonded sticks were subjected to the microtensile bond strength (µTBS) test. One-way ANOVA and Tukey's test were used to analyze the data. The failure mode was descriptively analyzed. The highest µTBS values were obtained when the resin-modified glass ionomer cement was repaired using the same material (p < 0.01). In addition, the mode of application of the universal adhesive system did not influence the repair bond strength of the resin-modified glass ionomer cement. Adhesive/mixed failures prevailed in all groups. Repair of resin-modified glass ionomers with the same material appears to be the preferred option to improve bond strength.

Asunto(s)

Resinas Compuestas , Recubrimiento Dental Adhesivo , Cementos de Ionómero Vítreo , Ensayo de Materiales , Cementos de Resina , Resistencia a la Tracción , Cementos de Ionómero Vítreo/química , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Cementos de Resina/química , Factores de Tiempo , Análisis de Varianza , Propiedades de Superficie , Reproducibilidad de los Resultados , Reparación de Restauración Dental/métodos , Valores de Referencia

RESUMEN

OBJECTIVES: To evaluate the marginal integrity (MI%) and to characterize specific properties of a thermoviscous bulk-fill resin composite, two regular bulk-fill resin composites, and a non-bulk-fill resin composite. MATERIALS AND METHODS: VisCalor bulk (VBF), Filtek One Bulk Fill (OBF), and Aura Bulk Fill (ABF) were evaluated. Filtek Z250 XT (ZXT) was used as non-bulk-fill control. MI% was evaluated in standardized cylindrical cavities restored with the composites by using a 3D laser confocal microscope. The following properties were characterized: volumetric polymerization shrinkage (VS%), polymerization shrinkage stress (Pss), degree of conversion (DC%), microhardness (KHN), flexural strength (FS), and elastic modulus (EM). Data were analyzed by one-way and two-way ANOVA, and Tukey HSD post-hoc test (α = 0.05). RESULTS: VBF presented the highest MI% and the lowest VS% and Pss (p < 0.05). DC% ranged from 59.4% (OBF) to 71.0% (ZXT). ZXT and VBF presented similar and highest KHN than OBF and ABF (p < 0.05). ABF presented the lowest FS (p < 0.05). EM ranged from 5.5 GPa to 7.7 GPa, with the values of ZXT and VBF being similar and statistically higher than those of OBF and ABF (p < 0.05). CONCLUSIONS: Thermoviscous technology employed by VisCalor bulk was able to improve its mechanical behavior comparatively to regular bulk-fill resin composites and to contribute to a better marginal integrity in restorations built up in cylindrical cavities with similar geometry to a class I cavity as well. Although presenting overall better physicomechanical properties, Z250 XT presented the worst MI%. CLINICAL RELEVANCE: The marginal integrity, which is pivotal for the success of resin composite restorations, could be improved using VisCalor bulk-fill. The worst MI% presented by Z250 XT reinforces that non-bulk-fill resin composites shall not be bulk-inserted in the cavity to be restored.

Asunto(s)

Resinas Compuestas , Adaptación Marginal Dental , Módulo de Elasticidad , Resistencia Flexional , Ensayo de Materiales , Polimerizacion , Propiedades de Superficie , Resinas Compuestas/química , Dureza , Microscopía Confocal , Técnicas In Vitro , Restauración Dental Permanente/métodos , Análisis del Estrés Dental

RESUMEN

OBJECTIVE: To evaluate the effects of UV postcuring times on color stability (CS), surface properties (wettability [°] and surface roughness [Ra]), and conversion of 3D-printed resins for temporary restorations. METHODS: Disc-shaped specimens (10.0×3.0 mm) and maxillary central incisors (8.2×10.3 mm) were fabricated using provisional 3D-printed resin (PriZma Bio Prov [PZ] and PrintaX AA TEMP [PX]) in A2 shade and subjected to UV postcure times of 0 (T0), 5 (T1), 10 (T2), and 15 (T3) minutes (n=15). The incisors were used for CS evaluation with a colorimeter. In contrast, discs were used to measure the contact angle using the sessile drop method, surface roughness with an optical profilometer, and degree of conversion with FT-NIR. For CS, Ra, contact angle, and degree of conversion, a two-way ANOVA with Bonferroni post-hoc test (α=0.05) was used. RESULTS: PX resin demonstrated greater color stability than PZ (p=0.001). Long UV postcuring times (10 to 15 minutes) will increase the contact angle (p=0.013) and stabilize the degree of conversion (p=0.01), while 5 to 10 minutes of UV postcuring will provide better surface smoothness (p=0.04) of both resins. CONCLUSIONS: Long UV postcuring times (10 to 15 minutes) lead to greater alterations in color, contact angle, and stability of the degree of conversion, while 5 to 10 minutes lead to a smoother surface of the 3D-printed temporary resins.

Asunto(s)

Color , Resinas Compuestas , Impresión Tridimensional , Propiedades de Superficie , Rayos Ultravioleta , Resinas Compuestas/química , Restauración Dental Provisional , Humanos , Factores de Tiempo , Ensayo de Materiales , Materiales Dentales/química , Humectabilidad

RESUMEN

OBJECTIVE: To evaluate the fracture behavior of human molars with extensive MOD restorations using short-fiber-reinforced resin composite of varying viscosities. MATERIALS AND METHODS: Human molars were randomly divided into seven groups (n = 12): intact teeth (control); restoration using conventional high-viscosity resin composite without (Filtek Z350XT, 3M) or with fibers (everX Posterior, GC); conventional low-viscosity resin composite without (Filtek Supreme Flowable, 3M) or with fibers (everX Flow Dentin Shade, GC); bulk-fill low-viscosity resin composite (Filtek Bulk Fill Flow, 3M) or with fibers (everX Flow Bulk Shade, GC). Restorations were performed on extensive MOD preparations, following the manufacturers' recommendations for each material. Specimens underwent fracture strength testing (N) and fracture pattern (%) categorized as repairable, possibly repairable, or non-repairable. Results were analyzed using a generalized linear model (N) and Fisher's exact test (%), with α = 0.05. RESULTS: Restorations performed with high-viscosity materials showed fracture strength values similar to the control and higher than those of restorations using low-viscosity resin composites (p < 0.0001), except for the bulk-fill low-viscosity resin composite with fibers (p > 0.05). Teeth restored using low-viscosity resin composite with fibers showed a higher % of repairable and possibly repairable fractures than the control (p = 0.0091). CONCLUSIONS: The viscosity of materials mediated the fracture strength, with restorations using high-viscosity resin composites promoting values similar to the intact tooth; however, the presence of fibers influenced the fracture pattern. CLINICAL SIGNIFICANCE: Teeth with MOD cavities restored with high-viscosity resin composites showed similar fracture strength to intact teeth. Fiber-reinforced low-viscosity resin composite for the base of restoration resulted in a more repairable/possibly repairable fracture pattern.

Asunto(s)

Resinas Compuestas , Diente Molar , Resinas Compuestas/química , Humanos , Viscosidad , Fracaso de la Restauración Dental , Restauración Dental Permanente/métodos , Análisis del Estrés Dental , Ensayo de Materiales , Fracturas de los Dientes/terapia

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the effect of an adhesive loaded with 0.2 % copper (Cu) and 5 % zinc oxide (ZnO) nanoparticles (Nps) on its adhesive properties and enzymatic activity at the hybrid layer ex vivo in a randomized clinical model. METHODS: Fifteen patients participated in this study, and a total of 30 third molars were used. Occlusal cavities (4 × 4 × 2 mm) were made in each tooth, and randomly divided into 2 groups: (i) Experimental group: commercial adhesive loaded with 0.2wt % CuNps and 5wt % ZnONps; and (ii) Control Group: non-loaded commercial adhesive. Teeth were restored with resin composite. Thirty days later, extractions were performed. Extracted teeth were longitudinally sectioned. Nps in powder were characterized by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) analysis. Microtensile bond strength (µTBS), degree of conversion (DC), and nanoleakeage (NL) tests were executed. In situ zymography (Zym) was performed to evaluate the gelatinolytic activity at the hybrid layer. Student's t-test (α = 0.05) was applied for all tests. RESULTS: µTBS and DC did not show significant differences (p > 0.05) between both groups. However, NL and gelatinolytic activity at the hybrid layer showed significant values (p < 0.05) for experimental group in comparison with control group. CONCLUSION: The addition of 0.2 % CuNps and 5 % ZnONps to a universal adhesive decreases NL and gelatinolytic activity at the hybrid layer, without jeopardizing its adhesive properties. SIGNIFICANCE: This randomized clinical trial with ex vivo analysis demonstrate that a commercial adhesive modified with 0.2wt % Cu and 5wt % ZnO Nps that does not affect its adhesive properties, reducing gelatinolytic activity and nanoleakage at the hybrid layer, which should contribute to an improvement of long term bonding-dentine clinical performance.

Asunto(s)

Resinas Compuestas , Cobre , Recubrimiento Dental Adhesivo , Microscopía Electrónica de Rastreo , Resistencia a la Tracción , Óxido de Zinc , Humanos , Óxido de Zinc/química , Cobre/química , Recubrimiento Dental Adhesivo/métodos , Resinas Compuestas/química , Nanopartículas/química , Recubrimientos Dentinarios/química , Dentina/efectos de los fármacos , Dentina/enzimología , Ensayo de Materiales , Masculino , Cementos de Resina/química , Adulto , Femenino , Propiedades de Superficie , Cementos Dentales/química , Tercer Molar , Restauración Dental Permanente/métodos , Espectrometría por Rayos X

RESUMEN

PURPOSE: To evaluate color change in ceramic veneers luted to enamel with light-cured, dual-cured resin luting agents, or heated resin composites, as well as to evaluate microhardness and diametral tensile strength of these luting agents. METHODS: For color analysis, 0.5 mm-thick leucite-reinforced glass ceramic veneers (IPS Empress CAD) were cemented onto 40 bovine dental blocks (n= 10) using RelyX Ultimate (RU) or RelyX Veneer (RV) resin-based luting agents, or Gradia Direct (GD) and Palfique Lx5 (P) heated resin composites. After luting, the specimens were subjected to thermocycling (10,000 cycles). Color analysis was performed before and after thermocycling (L*, a*, b*, ΔEab, ΔE00). For the microhardness (Knoop) and diametral tensile strength tests, specimens (Ø 6 x 2 mm) were made (RU, RV, GD, and P). The specimens were subdivided into eight groups (n=10) and light-cured through different ceramic sheets (thicknesses of 0.5 mm or 1.5 mm). Knoop microhardness was performed on the top surface in a microhardness tester, and diametral tensile strength on a universal testing machine. Data were submitted to statistical analysis, using two-way ANOVA, Tukey, and Kruskal-Wallis tests (α= 0.05). RESULTS: For the general color alteration, there was no statistically significant difference between the luting materials (ΔEab, P= 0.57; ΔE00, P= 0.50). There was no interaction between luting agent and thermocycling, for L* (P= 0.87), a* (P= 0.97) and b* (P= 0.95) values. Thermocycling significantly affected only the L* values (P= 0.047), which increased after the cycles. For microhardness, there was a statistically significant difference considering luting agents and ceramic thickness (P< 0.001). GD heated resin composite presented significantly lower microhardness values than all other materials, at both ceramic thicknesses. At a thickness of 1.5 mm, RU cement had higher microhardness values than RV and P materials. Diametral tensile strength was significantly influenced by luting agent (P= 0.01), but not by ceramic thickness (P= 0.55). Diametral tensile strength of GD resin composite was higher than that of the RU, but neither of these two materials differed from RV and P. CLINICAL SIGNIFICANCE: Heated resin composite, used as luting agents, showed similar color stability to light-cured and dual-cure resin cements, however its microhardness was affected by ceramic thickness.

Asunto(s)

Color , Resinas Compuestas , Coronas con Frente Estético , Dureza , Resistencia a la Tracción , Resinas Compuestas/química , Bovinos , Ensayo de Materiales , Animales , Cerámica/química , Calor , Cementos de Resina/química , Porcelana Dental/química , Análisis del Estrés Dental

RESUMEN

To evaluate the polymerization shrinkage stress and cuspal strain (CS) generated in an artificial (typodont) and in a natural tooth using different resin composites. Twenty artificial and 20 extracted natural molars were selected. Each tooth was prepared with a 4x4 mm MOD cavity. The natural and typodont teeth were divided into four experimental groups (n=10), according to the resin composite used: Filtek Z100 (3M Oral Care) and Beautifil II LS (Shofu Dental). The cavities were filled using two horizontal increments and the CS (µS) was measured by the strain gauge method. Samples were sectioned into stick-shaped specimens and the bond strength (BS) (MPa) was evaluated using a microtensile BS test. Shrinkage stress and CS were analyzed using 3D finite element analysis. No difference was found between the type of teeth for the CS as shown by the pooled averages: Natural tooth: 541.2 A; Typodont model: 591.4 A. Filtek Z100 CS values were higher than those obtained for Beautifil II LS, regardless of the type of teeth. No statistical difference was found for the BS data. Adhesive failures were more prevalent (79.9%). High shrinkage stress values were observed for Filtek Z100 resin, regardless of tooth type. The CS of typodont teeth showed a shrinkage stress effect, generated during restoration, equivalent to that of natural teeth.

Asunto(s)

Resinas Compuestas , Análisis del Estrés Dental , Análisis de Elementos Finitos , Ensayo de Materiales , Polimerizacion , Estrés Mecánico , Resistencia a la Tracción , Resinas Compuestas/química , Humanos , Valores de Referencia , Propiedades de Superficie , Reproducibilidad de los Resultados , Recubrimiento Dental Adhesivo/métodos , Corona del Diente

RESUMEN

Restaurações diretas em resina composta são amplamente utilizadas em odontologia para restaurar dentes posteriores. Todavia, quando há grande destruição coronária, onde a distância do istmo excede dois terços da distância intercuspídea, as restaurações indiretas em resina composta são indicadas. O presente estudo teve como objetivo relatar a análise de um prontuário de um paciente que recebeu uma restauração indireta em resina composta em dente posterior amplamente destruído. Através da análise de prontuários de pacientes atendidos nas disciplinas de Estágios Supervisionados do Curso de Odontologia da FSG Centro Universitário no ano de 2023, foi selecionado um prontuário de um paciente que compareceu a clínica odontológica da FSG com uma restauração em amálgama fraturada com reparo em resina composta que apresentou sintomatologia dolorosa. O procedimento diagnóstico ocorreu através de exame clínico e radiográfico, que constatou a indicação de substituição da restauração insatisfatória e realização de uma restauração indireta em resina composta. Os resultados estéticos e funcionais apresentados demostraram a viabilidade da técnica restauradora indireta em resina composta para reabilitar dentes posteriores com ampla destruição coronária(AU)

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Direct composite resin restoration are widely used in dentistry to restore posterior teeth. However, when there is large coronary destruction, that the distance from the isthmus exceeds two- thirds of the intercuspal distance, indirect composite resin restorations are indicated. This study aimed to report the analysis of a dental record of a patient who received an indirect restoration in composite resin in a badly destroyed posterior tooth. Through the analysis of dental records of patients seen in the disciplines of Supervised Internship of the Dentistry Course at FSG Centro Universitário in the year 2023, the dental record of a patient who attended the FSG dental clinic with fractured amalgam restoration with composite resin repair was selected who had painful symptoms. The diagnostic procedure took place through clinical and radiographic examination, which revealed the indication of replacing the unsatisfactory restoration and carrying out an indirect restoration in composite resin.The aesthetic and functional results presented demonstrated the viability of the indirect composite resin restoration technique for rehabilitating posterior teeth with extensive coronal destruction(AU)

Asunto(s)

Resinas Compuestas , Restauración Dental Permanente , Reparación de Restauración Dental , Atención Odontológica

RESUMEN

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.

Asunto(s)

Compuestos de Calcio , Fosfatos de Calcio , Ensayo de Materiales , Silicatos , Silicatos/química , Compuestos de Calcio/química , Fosfatos de Calcio/química , Espectroscopía Infrarroja por Transformada de Fourier , Durapatita/química , Resistencia Flexional , Ácidos Polimetacrílicos/química , Polietilenglicoles/química , Bisfenol A Glicidil Metacrilato/química , Resinas Compuestas/química , Vidrio/química , Calcio/química , Espectrofotometría , Fenómenos Químicos , Dióxido de Silicio , Compuestos de Bario

RESUMEN

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.

Asunto(s)

Resinas Compuestas , Resistencia Flexional , Pruebas de Dureza , Dureza , Ensayo de Materiales , Resinas Compuestas/química , Factores de Tiempo , Análisis de Varianza , Reproducibilidad de los Resultados , Valores de Referencia , Propiedades de Superficie , Temperatura

RESUMEN

OBJECTIVE: To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months. METHODS: Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05). RESULTS: Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05). CONCLUSION: Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service. CLINICAL SIGNIFICANCE: The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch.

Asunto(s)

Resinas Compuestas , Restauración Dental Permanente , Sensibilidad de la Dentina , Humanos , Resinas Compuestas/química , Resinas Compuestas/uso terapéutico , Restauración Dental Permanente/métodos , Femenino , Masculino , Método Doble Ciego , Adulto , Persona de Mediana Edad , Curación por Luz de Adhesivos Dentales , Materiales Dentales/química , Cementos de Resina/química , Adulto Joven , Diente Molar

RESUMEN

DESIGN: Double-blind (participant and outcome assessor), randomised, non-inferiority, two-arm (1:1 allocation) clinical trial. CASE SELECTION: The study included children aged 4-8 years old from public schools in Tietê, Brazil, who had mesio-occlusal carious lesions, into dentine, in primary molars. The carious teeth had to be asymptomatic of pulpal involvement. The children had to be medically fit and cooperative for dental treatment within their classroom environment. Consent was gained from a parent/guardian prior to entering the study. Children with carious lesions in multiple teeth, only one tooth was included, which was selected by a random draw. Treatment on other teeth would be carried out in the nearest health centre. DATA ANALYSIS: The primary outcome was the 2-year survival of the restorations, analysed using Kaplan-Meier survival curves and Cox regression (α = 5%). Costs for materials and professional services were recorded in Brazilian Reais (R$), converted to US dollars (US$), and analysed using Monte Carlo simulation. RESULTS: Of the 152 children enrolled (76 per group), 121 (79%) were evaluated at the 2-year mark. Overall, the 2-year survival rate of the restorations was 39% (EF: 45%; RSC: 32%), with no significant difference between the two groups. The total cost of restorations with RSC was lower than with EF, resulting in a cost saving of US$6.18 per restoration. CONCLUSION: After 2 years, Riva Self Cure demonstrated comparable survival rates to Equia Forte for mesio-occlusal restorations in primary molars, while being more cost-effective from a Brazilian perspective.

Asunto(s)

Caries Dental , Humanos , Niño , Caries Dental/terapia , Preescolar , Femenino , Masculino , Brasil , Método Doble Ciego , Tratamiento Restaurativo Atraumático Dental/métodos , Restauración Dental Permanente/métodos , Resinas Compuestas , Diente Molar