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Estabilidade de cor é um requisito estético fundamental das resinas acrílicas provisórias, em especial quando esses materiais são submetidos a longos períodos na cavidade oral. Embora resinas acrílicas temporárias novas e aprimoradas estejam disponíveis, os efeitos da variação térmica e de soluções antissépticas na estabilidade de cor de resinas acrílicas provisórias ainda não foram completamente elucidados. Portanto, este estudo avaliou a coloração de resinas autopolimerizáveis polimetilmetacrilato (PMMA) e bis-acrilo submetidas à termociclagem e imersão em clorexidina. Amostras padronizadas (n=10) foram preparadas de duas resinas acrílicas temporárias a base de PMMA (Alike® e Duralay®). Foram realizadas três avaliações de cor (T1 ­ 24h após o preparo da amostra, T2 ­ após termociclagem e T3 ­ após termociclagem e imersão em clorexidina) por meio de espectrofotômetro eletrônico de seleção de sombra (Vita Easy Shade). Os dados obtidos foram analisados por ANOVA e teste t (α=0,05). As resinas de PMMA Alike e Duralay apresentaram alteração de cor após a termociclagem e também após a imersão em clorexidina.

Color stability is a fundamental aesthetic requirement for temporary acrylic resins, especially when these materials are subjected to long periods in the oral cavity. Although new and improved temporary acrylic resins are available, the effects of thermal variation and antiseptic solutions on the color stability of temporary acrylic resins have not yet been fully elucidated. Therefore, this study evaluated the color of self-polymerizing resins polymethyl methacrylate (PMMA) and bis-acryl subjected to thermocycling and immersion in chlorhexidine. Standardized samples (n=10) were prepared from two PMMA-based temporary acrylic resins (Alike® and Duralay®). Three color evaluations were carried out (T1 ­ 24h after sample preparation, T2 ­ after thermocycling and T3 ­ after thermocycling and immersion in chlorhexidine) using an electronic shade selection spectrophotometer (Vita Easy Shade). The data obtained were analyzed by ANOVA and t test (α=0.05). PMMA Alike and Duralay resins showed color changes after thermocycling and also after immersion in chlorhexidine.

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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.

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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.

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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.

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The objective was to compare the color match and color stability behavior of single- and multi-shade resin-based composites (RBCs) used for direct restorations. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized clinical trials evaluating the shade performance of single-shade RBCs in direct restorations were included. A search of the scientific literature was performed in five databases (April 2024). The meta-analysis was performed using RevMan 5.4, calculating the risk difference (RD) and 95% confidence interval (CI) of the dichotomous outcome using a random effects model. Bias was assessed using the RoB 2.0 tool, and certainty of evidence was assessed using the GRADEpro tool. Four studies were selected, with 263 restorations analyzed. The results showed comparable performance between single-shade RBCs and multi-shade RBCs in terms of color match and color stability over 12 months. Three studies had a low risk of bias with all expected results, and one study had some concerns. The certainty of evidence for color stability was considered low for all follow-up periods due to the small number of events and sample size. According to the United States Public Health Service Evaluation (USPHS) and the World Dental Federation (FDI), there is comparable clinical color performance between single-shade and multi-shade RBCs over 12 months.

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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).

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).

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).

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Objective: Compare the surface roughness of two composite resins after immersion in carbonated beverages. Materials and methods: 160 resin discs (6 x 2 mm) were divided into 8 groups (n=20 per group) according to type of resin (Filtek™ Z350 XT® and Palfique LX5®) and type of immersion in beverages (distilled water, Coca Cola®, Inca Kola® and Kola Escocesa®. The immersions were carried out under a structured cycle: 4 immersions a day for 5 days, intermediate storage in distilled water and overnight incubation for 8 h at 37°C. The measurements with the roughness meter were evaluated in three times: baseline, 7 and 14 days. The three-way Anova test was used at P<0.05. Results: Roughness showed differences only for the individual factors of time (P<0.000) and resin (P=0.000), and for the interaction time*drink (P=0.000) and resin*drink (P=0.003). Roughness was higher with Filtek Z350 XT® immersed with Inca Kola® (0.85 ± 0.37) than 14 days compared to other times (P=0.035) and with Palfique LX5 immersed in Coca Cola® at 7 days (1.61 ± 0.42) and in Inca Kola® at 14 days (1.66 ± 0.56) compared to distilled water (P<0,05). Conclusion: Surface roughness was affected by the type of resin, the type of soft drink and the immersion time. The roughness was greater with the Palfique LX5® nanohybrid resin, the Inca Kola® drink and after 14 days of immersion.

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El avance de la tecnología permite realizar cambios en la rehabilitación y estética, reduce los tiempos de trabajo y disminuye los riesgos que se presentan al momento de utilizar materiales convencionales para la toma de impresiones. Existen dos técnicas que se pueden emplear, la analógica y la digital; la primera presenta mayores riesgos que el operador no puede controlar, así como tiempos más prolongados. Este reporte describe la rehabilitación bucal en dos pacientes con desgaste dental, se optó por usar ambas técnicas, la analógica y la digital, como tratamiento; en la primera se empleó el encerado convencional y en la segunda el software Exocad para el encerado digital. Finalmente en ambos casos se aplicó (AU)

The advance of technology has allowed changes in rehabilitation and esthetics, providing shorter working times and reducing the risks that occur when using conventional materials for taking impressions. There are two techniques that can be used, analog and digital, the first one presents greater risks that the operator cannot control, as well as more time. This report describes the oral rehabilitation in patients with dental wear. The treatment was carried out using the analogical and digital techniques, the former using conventional waxing and the latter using Exocad software for the digital waxing; finally, in both cases the injection technique with high-load Flow resin was used (AU)

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Objective: To evaluate the influence of opacity and the layering technique on the fluorescence of different composite resins. Materials and Methods: Two opacities (enamel and dentin) and the layering technique (enamel + dentin) of the composite resins: Filtek® Z350 and Palfique LX5 were evaluated in vitro. Composite resin discs were fabricated using a preformed matrix of 10 mm diameter and 0.5 mm thick for the single opacity groups and 10 mm thick for the layering technique groups, using 2 layers of 0.5 mm thickness of each opacity (n = 5). Specimens were analyzed using the Raman spectroscopy method. Data were analyzed using the Kruskall-wallis and Mann-Whitney U tests. Results: When evaluating the intensity of fluorescence, no statistically significant difference was found when comparing the layering technique and enamel opacity (p2> 0.05) and an increase in the dentin opacity value for both brands of composite resin. Regarding wavelength, no statistically significant difference was found when comparing the layering technique with enamel opacity and dentin opacity for both Filtek® Z350 and Palfique LX5® composite resins (p2 > 0.05). Conclusions: The fluorescence intensity of the layering technique is similar to enamel opacity for both composite resins. Likewise, the wavelength of the layering technique is similar to the enamel opacity and dentin opacity for both brands.

Objetive: Evaluar la influencia de la opacidad y de la técnica de estratificación en la fluorescencia de diferentes resinas compuestas. Materiales y Métodos: Se evaluó in vitro 2 opacidades (Esmalte y Dentina) y la técnica de estratificación (Esmalte + Dentina) de las resinas compuestas: Filtek® Z350 y Palfique LX5. Se fabricaron discos de resina compuesta, utilizando una matriz preformada de 10 mm de diámetro y 0,5 mm de grosor para los grupos de opacidad única y 10 mm de grosor para los grupos de técnica estratificada, utilizando 2 capas de 0,5 mm de cada opacidad (n = 5). Los especímenes se analizaron mediante el método de Espectroscopía Raman. Los datos se analizaron utilizando la prueba de Kruskall-wallis y Prueba U de Mann Whitney. Resultado: Al evaluar la intensidad de fluorescencia no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte para ambas marcas de resina compuesta Filtek® Z350 y para Palfique LX5® (p2 > 0,05). Para longitud de onda no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte y Técnica estratificada VS Opacidad Dentina para ambas resinas compuesta Filtek® Z350 y Palfique LX5® (p2> 0,05). Conclusión: La intensidad de fluorescencia de la técnica estratificada es similar a la opacidad Esmalte para ambas resinas compuestas. De igual manera la longitud de onda de la técnica estratificada es similar a la opacidad Esmalte y opacidad Dentina para ambas marcas.

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The present study aimed to characterize the microstructure of a temporary 3D printing polymer-based composite material (Resilab Temp), evaluating its optical properties and mechanical behavior according to different post-curing times. For the analysis of the surface microstructure and establishment of the best printing pattern, samples in bar format following ISO 4049 (25 × 10 × 3 mm) were designed in CAD software (Rhinoceros 6.0), printed on a W3D printer (Wilcos), and light-cured in Anycubic Photon for different lengths of time (no post-curing, 16 min, 32 min, and 60 min). For the structural characterization, analyses were carried out using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The mechanical behavior of this polymer-based composite material was determined based on flexural strength tests and Knoop microhardness. Color and translucency analysis were performed using a spectrophotometer (VITA Easy Shade Advanced 4.0), which was then evaluated in CIELab, using gray, black, and white backgrounds. All analyses were performed immediately after making the samples and repeated after thermal aging over two thousand cycles (5-55 °C). The results obtained were statistically analyzed with a significance level of 5%. FT-IR analysis showed about a 46% degree of conversion on the surface and 37% in the center of the resin sample. The flexural strength was higher for the groups polymerized for 32 min and 1 h, while the Knoop microhardness did not show a statistical difference between the groups. Color and translucency analysis also did not show statistical differences between groups. According to all of the analyses carried out in this study, for the evaluated material, a post-polymerization time of 1 h should be suggested to improve the mechanical performance of 3D-printed devices.

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During the preparation of fixed prosthesis (including individual bridges and crowns) it is important to select the materials that have the best features and properties to predict a successful clinical treatment. The objective of this study was to determine if the chemical and structural characteristics could cause to increase the fracture resistance, we used four bis-acryl resins Luxatemp, Protemp, Structur and Telio. Three-points bending by Flexural test were performed in ten bars and they were carried out to compare with Anova test. In addition, the bis-acryl resins were analyzed by scanning electron microscopy, to analyze microstructure and morphology and the molecular structure were performed by Infrared Spectroscopy through Attenuated Total Reflectance. A higher flexural strength was found in Luxatemp and Structur with, no significant differences between this study groups. Regarding Protemp and Telio, these study groups showed a lower flexural strength when were compared with Luxatemp and Structur. These results corroborate SEM and ATR analysis because Luxatemp sample showed a regular size particle on the surface and chemically presents a long cross-linkage polymer chain. The presence of CO3, SiO2 and N-H groups as a fillers particle interacting with OH groups cause a higher flexural strength compared with another groups.

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OBJECTIVES: To evaluate the longevity of resin composite restorations placed in posterior teeth by dental students, using data from electronic records from 2008 to 2019. MATERIALS AND METHODS: Demographic (gender and age) and clinical variables (dental group, position in dental arch, and the number of restored surfaces) were evaluated. The 5-year follow-up was assessed according to the day the restoration was placed. Kaplan-Meier curves were generated to calculate the annual failure rate. Data were analyzed by Chi-Square, Kruskal-Wallis, and Mann-Whitney tests (α = 0.05). RESULTS: In total, 3.883 records relative to return periodicity were analyzed. The final sample consisted of 900 restorations from 479 patients. The majority were females, aged between 31 and 60. In total, 256 failures were reported (success rate = 78%), showing an annual failure rate of 2.05%. The main reasons for failures were restoration replacement (55.5%), endodontics (21.9%), prosthetics (14.5%) and extraction (8.2%). There was a higher risk of failure in restorations involving three or more surfaces (p = 0.000) and in patients over 60 years (p < 0.001). In females (p = 0.030), molars (p = 0.044), and maxillary teeth (p = 0.038) failed in a shorter time. CONCLUSIONS: Resin composite restorations placed in permanent posterior teeth by dental students had high survival rates. The main reason for failure was the replacement of restorations. The age group and the number of restored surfaces significantly affected the success of the restorations. CLINICAL RELEVANCE: The electronic health records over 12 years showed that 78% of the resin restorations in posterior teeth placed by dental students were successful for a minimum of five years.

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Objetivo: Cuando las resinas compuestas son expuestas a procesos de envejecimiento naturales en boca, como es el ciclaje térmico, pueden sufrir un deterioro en sus propiedades ópticas. El objetivo de este estudio fue evaluar la influencia del envejecimiento térmico sobre la estabilidad del color de dos resinas compuestas. Materiales y métodos: Se confeccionaron 120 pas- tillas de resinas compuestas, divididas en dos grupos: uno de resina Spectra Smart (n=60) y otro de resina Filtex Z350 XT (n=60). Estas muestras fueron sometidas a distintos regíme- nes de ciclaje térmico de 0, 10.000, 20.000 y 30.000 ciclos con temperaturas de entre 5 ºC +/- 2 ºC y 55 ºC +/- 2 °C. Los parámetros de color CIE L*a*b* de cada muestra se mi- dieron con un espectrofotómetro antes y después del proceso de envejecimiento. Las diferencias de color se calcularon me- diante la fórmula CIELAB (ΔE). Los datos fueron analizados estadísticamente usando la prueba no paramétrica de Kruskal Wallis y de U-Mann Whitney. Resultados: Los distintos regímenes de termociclado produjeron cambios de color estadísticamente significativos en ambos materiales. El material que tuvo menor estabilidad cromática fue Spectra Smart aunque sin diferencias estadísti- camente significativas. Conclusión: El envejecimiento térmico simulado a tres años afecta la estabilidad de color de las muestras, tanto de las resinas Spectra Smart, como de Filtex Z350 XT, sin alcanzar los valores que clínicamente determinarían la necesidad del reemplazo de las restauraciones (AU)

Aim: When composite resins are exposed to natural ag- ing processes in the mouth, such as the thermal cycling, they may suffer a deterioration in their optical properties. The aim of this study was to evaluate the influence of thermal aging on the color stability of two composite resins. Materials and methods: 120 composite resins tablets were made, divided into two groups: one of Spectra Smart res- in (n=60) and another of Filtex Z350 XT resin (n=60). These were subjected to different thermal cycle regimes of 0, 10,000, 20,000 and 30,000 cycles with temperature between 5 °C +/- 2 °C and 60 °C +/- 2 °C. The CIE L*a*b* color parameters of each sample were measured with a spectrophotometer before and after the aging process. Color differences were calculat- ed using the CIELAB formula (ΔE). The data were statisti- cally analyzed using the non-parametric Kruskal Wallis and U-Mann Whitney tests. Results: The different thermocycling regimes produce statistically significant color changes in both materials. The material that had the least chromatic stability was Spectra Smart, although without statistically significant differences. Conclusion: Simulated 3 year thermal aging affects the color stability of the samples, both Spectra Smart resins and Filtex Z350 XT, without reaching the values that would clini- cally determine the need to replace the restorations (AU)

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SUMMARY: Over time, Goldner's trichrome staining has been essential in paraffin soft tissue research. However, its classic application involves prior decalcification, generating disadvantages in the integrity of the samples and the interpretation of results. This study seeks to overcome the limitations associated with decalcification when applying Goldner's trichrome stain with plastic resins. It focuses on detailed visualization of non-decalcified bone and dental samples in animal models. Samples of jaw and tooth from a dog (Canis familiaris) were used, as well as tibia from a rabbit (Oryctolagus cuniculus) with a titanium dental implant and bone graft substitute. Adjustments were made to the original protocol, including a surface treatment prior to staining. Plastination and inclusion in specific plastic resins were part of the process. The microplastinated and stained samples showed optimal quality for optical microscopy. Those from dogs allowed detailed observation of the tooth-periodontal tissue relationship, while those from rabbits revealed a clear differentiation between mineralized and osteoid bone tissue. The staining made it easy to examine the precise interface between soft tissues, bone graft, and implant. The successful adaptation of Goldner's trichrome stain to specimens in plastic resins represents a significant advance in histological investigation of hard tissues. This methodology stands out as an effective tool to evaluate implants and biomaterials in animal models, providing detailed visualization without compromising the integrity of the samples. The combination of histochemistry and plastic resins offers a valuable alternative for microanatomical studies, opening new possibilities in hard tissue research and evaluation of bone structures.

A lo largo del tiempo, la tinción tricrómica de Goldner ha sido esencial en la investigación de tejidos blandos en parafina. Sin embargo, su aplicación clásica conlleva la descalcificación previa, generando desventajas en la integridad de las muestras y la interpretación de resultados. Este estudio busca superar las limitaciones asociadas con la descalcificación al aplicar la tinción tricrómica de Goldner con resinas plásticas. Se enfoca en visualizar detalladamente muestras óseas y dentales no descalcificadas en modelos animales. Se emplearon muestras de mandíbula y diente de perro (Canis familiaris), así como tibia de conejo (Oryctolagus cuniculus) con implante dental de titanio y substituto de injerto óseo. Se realizaron ajustes al protocolo original, incluyendo un tratamiento superficial previo a la tinción. La plastinación y la inclusión en resinas plásticas específicas fueron parte del proceso. Las muestras microplastinadas y teñidas mostraron una calidad óptima para microscopía óptica. Las de perro permitieron la observación detallada de la relación diente-tejido periodontal, mientras que las de conejo revelaron una clara diferenciación entre tejido óseo mineralizado y osteoide. La tinción facilitó examinar la interface precisa entre tejidos blandos, injerto óseo e implante. La adaptación exitosa de la tinción tricrómica de Goldner a muestras en resinas plásticas representa un avance significativo en la investigación histológica de tejidos duros. Esta metodología destaca como una herramienta eficaz para evaluar implantes y biomateriales en modelos animales, brindando una visualización detallada sin comprometer la integridad de las muestras. La combinación de histoquímica y resinas plásticas ofrece una alternativa valiosa para estudios microanatómicos, abriendo nuevas posibilidades en la investigación de tejidos duros y evaluación de estructuras óseas.

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This study aimed to evaluate the interface of universal adhesive (UA) with bulk-fill resin (BF) and dentin, after endodontic irrigation. The pulp chamber of 96 molars was irrigated with chlorhexidine 2% (CHX) or sodium hypochlorite 5.25% (NaOCl) and restored according to three restorative protocols. Microtensile bond strength (µTBS) and nanoleakage tests were performed after 24 h of thermocycling. Kruskal Wallis, Mann-Whitney and Wilcoxon were performed (p < 0.05). Comparing restorative systems, a difference was found only when irrigated with CHX after 24 h. CHX provided higher µTBS than NaOCl after 24 h for two restorative protocols; after thermocycling, NaOCl provided the greatest µTBS than CHX for one group. Decreased µTBS was observed for all restorative systems when CHX was used after thermocycling. NaOCl demonstrated the highest nanoleakage. The composition of UA influenced the immediate adhesion and sealing to BF when CHX was used; ageing has a deteriorating effect on adhesion and sealing for all restorative systems.

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Oral infections occur due to contact between biofilm rich in Candida albicans formed on the inner surface of complete dentures and the mucosa. This study investigated historical advances in the prevention and treatment of oral mucosal infection and identified gaps in the literature. Bibliographic research was conducted, looking at PubMed, Embase, Web of Science, and Scopus, where 935 articles were found. After removing duplicates and excluding articles by reading the title and abstract, 131 articles were selected for full reading and 104 articles were included. Another 38 articles were added from the gray literature. This review followed the PRISMA-ScR guidelines. The historical period described ranges from 1969 to 2023, in which, during the 21st century, in vitro and in vivo studies became more common and, from 2010 to 2023, the number of randomized controlled trials increased. Among the various approaches tested are the incorporation of antimicrobial products into prosthetic materials, the improvement of oral and denture hygiene protocols, the development of synthetic and natural products for the chemical control of microorganisms, and intervention with local or systemic antimicrobial agents. Studies report good results with brushing combined with sodium hypochlorite, and new disinfectant solutions and products incorporated into prosthetic materials are promising.

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This study aimed to answer the question formulated according to the PICO strategy: 'Which essential oils show antimicrobial activity against biofilms formed on dental acrylic resin?' composed by population (dental acrylic resin), intervention (application of essential oils), comparison (denture cleansers, antifungal drugs, chlorhexidine, and oral mouthwashes), and outcome (antibiofilm activity). In vitro experimental studies evaluating the activity of EOs on biofilm formed on acrylic resin were included. PRISMA guidelines were followed, and the search was performed in the PubMed, Science Direct, Embase, and Lilacs databases and in the gray literature using Google Scholar and ProQuest in December 2023. A manual search of the reference lists of the included primary studies was performed. Of the 1467 articles identified, 37 were selected for full-text reading and 12 were included. Twelve EOs were evaluated, of which 11 showed activity against Candida spp., 3 against Staphylococcus aureus, and 1 against Pseudomonas aeruginosa. The EOs of Cymbopogon citratus, Cinnamomum zeylanicum, and Cymbopogon nardus showed higher action than chlorhexidine, C. nardus higher than Listerine, C. citratus higher than nystatin, and Melaleuca alternifolia higher than fluconazole and nystatin. However, chlorhexidine was more effective than Lippia sidoides and Salvia officinalis, sodium hypochlorite was more effective than L. sidoides, nystatin was more effective than Zingiber officinale, Amphotericin B more effective than Eucalyptus globulus and M. alternifolia. In conclusion, the EOs of C. zeylanicum, C. citratus, C. nardus, and M. alternifolia showed antimicrobial activity to reduce biofilm on dental acrylic resin.

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OBJECTIVES: This study aimed at comparing the microtensile bond strength (MTBS) and interfacial adaptation of a modern self-curing and a light-curing restorative bulk-fill composite to a conventional composite applied with the layering technique. METHODS: Forty-eight occlusal cavities were divided in three main groups (16/group) based on tested materials: (i) STELA, bulk-fill self-curing restorative (STELA, SDI Ltd.); (ii) 3 M-BULK, bulk-fill composite (Filtek One Bulk-Fill, 3 M Oral Care); and (iii) 3 M-CTR, a conventional composite (Filtek Supreme XTE, 3 M Oral Care). These were used in combination with their adhesives in self-etch (SE) or etch-and-rinse (ER) mode. Specimens stored in artificial saliva (24 h or 12 months) were evaluated for MTBS and fractography. The interfacial analysis was performed through confocal microscopy. ANOVA and Fisher's LSD post hoc tests were performed with a level of significance of 5%. RESULTS: All the tested materials applied in ER mode presented (24 h) greater bond strength than in SE mode. Although all materials showed a significant drop in the bond strength after prolonged storage, STELA showed the highest bonding performance and interfaces with few gaps. 3 M-BULK had the lowest bond strength and an interface with several voids and gaps. CONCLUSIONS: All materials were affected by interface degradation and bonding reduction over prolonged aging. However, their use in combination with adhesives applied in ER mode may offer greater immediate bonding performance. CLINICAL RELEVANCE: The use of restorative light-curing bulk-fill composites may generate gaps at the bonding interface and voids. STELA may represent a suitable alternative to avoid such issues.

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RESUMEN Objetivo : Comparar la microdureza de la resina compuesta con técnica índex convencional y modificada con cubeta impresa en dos fotopolimerizaciones. Materiales y métodos : Se contó con seis grupos de estudio de acuerdo a la técnica y a la cantidad de fotopolimerizaciones: técnica directa con una fotopolimerización (D1F), directa con dos fotopolimerizaciones (D2F), índex convencional con una fotopolimerización (IC1F), índex convencional con dos fotopolimerizaciones (IC2F), índex modificada con una fotopolimerización (IM1F), índex modificada con dos fotopolimerizaciones (IM2F). Se utilizaron quince muestras por cada grupo. Las muestras tuvieron dimensiones de 2 mm de altura por 5 mm de diámetro. Se realizó la fotopolimerización siguiendo las indicaciones del grupo al que corresponde, para luego someter a la prueba de dureza de Vickers a tres indentaciones por cada cara con carga de 200 g por 15 segundos. Se realizaron dos registros de microdureza, una superficial y otra a 2 mm. Se recolectaron los datos en el instrumento confeccionado y fueron procesados mediante SPSS v. 26. Resultados : Existe una diferencia significativa entre los grupos de microdureza superficial de primera fotopolimerización (p < 0,001); y también existe diferencia significativa entre los grupos de microdureza a 2 mm de primera fotopolimerización (p < 0,001). Asimismo, no existen diferencias significativas entre los grupos de microdureza superficial de segunda fotopolimerización (p = 0,519) ni en los grupos de microdureza a 2 mm de segunda fotopolimerización (p = 0,279). Conclusiones: No existen diferencias significativas en la microdureza superficial y a 2 mm de profundidad con técnica índex convencional y modificada en cubeta impresa en dos fotopolimerizaciones.

ABSTRACT Objective : To compare the microhardness of composite resin with conventional and modified index techniques with a printed tray in two light cures. Materials and methods : There were six study groups according to the technique and the number of photopolymerizations: direct technique with one photopolymerization (D1F), direct with two photopolymerizations (D2F), conventional index with one photopolymerization (IC1F), conventional index with two photopolymerizations (IC2F), modified index with one photopolymerization (IM1F), modified index with two photopolymerizations (IM2F). Fifteen samples were used for each group. The samples had dimensions of 2 mm in height by 5 mm in diameter. The photopolymerization was performed following the indications of the group to which it corresponds and then subjected to the Vickers hardness test with three indentations on each side with a load of 200 g for 15 seconds. Two microhardness recordings were made, one superficial and the other at 2 mm. Results : There is a significant difference between the first light-curing surface microhardness groups (p < 0.001), and there is also a significant difference between the first light-curing 2 mm microhardness groups (p < 0.001). Likewise, there are no significant differences between the second light-curing surface microhardness groups (p = 0.519) or the second light-curing 2 mm microhardness groups (p = 0.279). Conclusions : There are no significant differences in surface microhardness and microhardness at 2 mm depth with conventional and modified index techniques in printed trays in two photopolymerizations.

RESUMO Objetivo : Comparar a microdureza da resina composta com a técnica de índice convencional e modificada com moldeira impressa em duas fotopolimerizações. Materiais e métodos : Foram constituídos seis grupos de estudo de acordo com a técnica e o número de ciclos de fotopolimerização: técnica direta com um ciclo de fotopolimerização (D1F), direta com dois ciclos de fotopolimerização (D2F), índice convencional com um ciclo de fotopolimerização (IC1F), índice convencional com dois ciclos de fotopolimerização (IC2F), índice modificado com um ciclo de fotopolimerização (IM1F), índice modificado com dois ciclos de fotopolimerização (IM2F). Foram utilizadas quinze amostras para cada grupo. Os espécimes tinham 2 mm de altura por 5 mm de diâmetro. A fotopolimerização foi efetuada de acordo com as indicações do grupo a que corresponde, e depois submetida ao teste de dureza Vickers com três indentações de cada lado com uma carga de 200 g durante 15 segundos. Foram efetuados dois registos de microdureza, um superficial e outro a 2 mm. Os dados foram recolhidos no instrumento e processados utilizando o SPSS v. 26. Resultados : Há uma diferença significativa entre os primeiros grupos de microdureza superficial fotopolimerizável (p < 0,001); e há também uma diferença significativa entre os primeiros grupos de microdureza de 2 mm fotopolimerizável (p < 0,001). Da mesma forma, não há diferença significativa entre os grupos de microdureza da superfície do segundo fotopolimerizador (p = 0,519) e nos grupos de microdureza de 2 mm do segundo fotopolimerizador (p = 0,279). Conclusões : Não existem diferenças significativas na microdureza da superfície e na microdureza a 2 mm de profundidade com a técnica de índice convencional e modificada em duas fotopolimerizações.