Effect of Ceramic Thickness on the Bond Strength to Resin-Luting Agents before and after Thermal Cycling

Abstract This study investigated microshear bond strength (µSBS) of two (2) dual-cured resin-luting agents (RelyX™ Ultimate and RelyX™ U200) when photoactivated through varying thicknesses of lithium disilicate, with or without thermal cycling. Discs of IPS e.max Press of 0.5, 1.5, and 2 mm in thickness were obtained. Elastomer molds (3.0 mm in thickness) with four cylinder-shaped orifices 1.0 mm in diameter, were placed onto the ceramic surfaces and filled with resin-luting agents. A Mylar strip, glass plate, and load of 250 grams were placed over the filled mold. The load was removed and the resin-luting agents were photoactivated through the ceramics using a single-peak LED (Radii Plus.) All samples were stored in distilled water at 37oC for 24 h. Half of the samples were subjected to thermal cycling (3,000 cycles; 5ºC and 55ºC). All samples were then submitted to µSBS test using a universal testing machine (Instron 4411) at a crosshead speed of 0.5 mm/min. Data were submitted to three-way ANOVA and Tukey post-hoc test (α=0.05). The mean µSBS at 24 h was significantly higher than after thermal cycling (p<0.05). No statistical difference was found between resin-luting agents (p > 0.05). The mean µSBS for groups photoactivated through 0.5 mm ceramic were significantly higher than 1.5 mm and 2.0 mm (p < 0.05). In conclusion, increased ceramic thicknesses reduced the bond strength of tested resin-luting agents to lithium disilicate. No differences were found between resin-luting agents. Thermal cycling reduced the bond strength of both resin-luting agents.

Resumo: Este estudo investigou a resistência de união ao microcisalhamento (RUµC) de dois (2) agentes de cimentação de resina dual (RelyX™ Ultimate e RelyX™ U200) quando fotoativados através de diferentes espessuras de dissilicato de lítio, com ou sem ciclagem térmica. Discos do IPS e.max Press de 0,5, 1,5 e 2 mm de espessura foram obtidos. Moldes de elastômero (3,0 mm de espessura) com quatro orifícios cilíndricos de 1,0 mm de diâmetro foram colocados sobre as superfícies cerâmicas e preenchidos com agentes de cimentação de resina. Uma tira Mylar, placa de vidro e carga de 250 gramas foram colocadas sobre o molde preenchido. A carga foi removida e os agentes de cimentação resinosos foram fotoativados através da cerâmica usando um LED de pico-único (Radii Plus). Todas as amostras foram armazenadas em água deionizada a 37oC por 24 h. Metade das amostras foi submetida a ciclagem térmica (3.000 ciclos; 5ºC e 55ºC). Todas as amostras foram então submetidas ao teste de RUµC usando uma máquina de teste universal (Instron 4411) com velocidade de 0,5 mm/min. Os dados foram submetidos à Análise de Variância três fatores e ao teste post-hoc de Tukey (α = 0,05). A média de RUµC em 24 h foi significativamente maior do que após a ciclagem térmica (p < 0,05). Não houve diferença estatística entre os cimentos resinosos (p > 0,05). As médias de RUµC para grupos fotoativados através de cerâmica de 0,5 mm foram significativamente maiores do que 1,5 mm e 2,0 mm (p < 0,05). Em conclusão, o aumento da espessura da cerâmica reduziu a resistência de união dos agentes de cimentação resinosos ao dissilicato de lítio. Não foram encontradas diferenças entre os agentes de cimentação resinosos. A ciclagem térmica reduziu a resistência de união de ambos os agentes de cimentação resinosos.

Color matching and color recovery in large composite restorations using single-shade or universal composites

Abstract This study assessed the color-matching ability and color recovery of unprepared teeth when using single-shade composites and a universal composite in large restorations. Buccal and palatine surface colors of molars were measured with a spectrophotometer (CIELAB) before preparing round cavities (6 mm in diameter, 2 mm in depth). The cavities were randomly filled with a single-shade composite (Omnichroma, Diamond One, or Vittra APS Unique) or a universal composite (Filtek Universal). Color measurements of the restored cavities were taken, and overall color differences (ΔEab and ΔE00) and differences in the whitening index for dentistry (ΔWID) from baseline were calculated. Additionally, visual assessments of a color match to the surrounding enamel were performed by forty evaluators (laypersons and undergraduate students of dentistry) in a viewing booth under illuminant D65, with rating scores from 0 (no color mismatch) to 4 (not acceptable). Data were analyzed using RM or one-way ANOVA (α = 0.05). Results showed that the restorations generally exhibited whiter colors (WID ranged from 27.9 to 41.3) than the unprepared teeth (WID ranged from 15.9 to 19.3). The composite Filtek Universal demonstrated the lowest color discrepancy (ΔWID = 8.6; ΔE00 = 10.8; and ΔE00 = 6.2), and no significant differences were observed among the evaluated single-shade composites. Furthermore, all composites showed similar and adequate color matches to the surrounding enamel. However, it is important to note that despite their ability to match the surrounding enamel reasonably, none of the composites evaluated in large restorations fully recovered the color observed in unprepared teeth.

Resumo Este estudo avaliou a habilidade de combinação de cores e recuperação de cor de dentes não preparados ao utilizar resinas compostas de única tonalidade e uma resina composta universal em grandes restaurações. As cores das superfícies bucais e palatinas de molares foram medidas com um espectrofotômetro (CIELAB) antes de preparar cavidades esféricas (6 mm de diâmetro, 2 mm de profundidade). As cavidades foram preenchidas aleatoriamente com uma resina composta de única tonalidade (Omnichroma, Diamond One ou Vittra APS Unique) ou com uma resina composta universal (Filtek Universal). Foram realizadas medições das cores das cavidades restauradas e calculadas as diferenças de cor globais (ΔEab and ΔE00)) e as diferenças no índice de clareamento para odontologia (ΔWID) em relação à cor inicial. Além disso, foram realizadas avaliações visuais da correspondência de cor com o esmalte circundante por quarenta avaliadores (leigos e estudantes de odontologia) em uma cabine de visualização sob iluminante D65, com pontuações de 0 (nenhuma discrepância de cor) a 4 (não aceitável). Os dados foram analisados usando RM ou ANOVA unidirecional (α = 0,05). Os resultados mostraram que as restaurações geralmente apresentavam cores mais brancas (WID variou de 27,9 a 41,3) do que os dentes não preparados (WID variou de 15,9 a 19,3). A resina composta Filtek Universal demonstrou a menor discrepância de cor (ΔWID = 8,6; ΔE00 = 10,8; and ΔE00 = 6,2), e não foram observadas diferenças significativas entre as resinas compostas de única tonalidade avaliadas. Além disso, todas as resinas compostas apresentaram correspondência de cor similar e adequada com o esmalte circundante. No entanto, é importante observar que, apesar de sua capacidade de corresponder razoavelmente com o esmalte circundante, nenhuma das resinas compostas avaliadas em grandes restaurações recuperou completamente a cor observada nos dentes não preparados.

Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Clinical application of lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture in the restoration of single anterior tooth loss / 口腔疾病防治

Objective@#To investigate the clinical effect of lithium disilicate glass ceramic cantilever resin-bonded fixed partial dentures (CRBFPDs) on single anterior tooth loss to provide a reference for the selection of restoration methods for single anterior tooth loss.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Forty-two patients with less than two anterior teeth with monomaxillary loss were included in this study. After 6 months, 1 year, 2 years, and 3 years, the aesthetic and functional effects of the restorations and the periodontal health status were evaluated, and the visual analog scale (VAS) was used to assess patient satisfaction.@*Results@#During the observation period, the connector fractured in one case within 3 months. One case had debonded within 2 years. The aesthetic restoration effect of all lithium disilicate glass ceramic CRBFPDs was categorized as Class A. The periodontal health was good, there was no clinical absorption in the soft and hard tissues of the abutment or subbridge, periodontal status according to the evaluation indices was classified as class A, and the total satisfaction rate of the patient was 100%.@*Conclusion@#For single anterior tooth loss patients, lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture can achieve the restoration effect of less invasion, better adhesion, aesthetics, comfort and good biocompatibility. With high patient satisfaction, it can be considered an ideal restoration method for replacing a single anterior tooth.

ARE CALCIUM SILICATE SEALERS LESS CYTOTOXIC AND GENOTOXIC THAN EPOXY RESIN SEALERS? A SYSTEMATIC REVIEW OF IN VITRO STUDIES

Aims: This systematic review aimed to evaluate whether calcium silicate-based sealers are less cytotoxicity and genotoxicity than epoxy resin-based sealers. Materials and Methods: Systematic searches were conducted for studies published up to September 27th, 2022, without restriction for language or year of publication, in the following databases: MEDLINE/PubMed, Scopus, Web of Science and Grey Literature Report. Only in vitrostudies that evaluated the cytotoxicity or genotoxicity of calcium silicate and epoxy resin-based sealers were included. The quality assessment was performed. Results: After duplicate removal and eligibility criteria assessment, a total of thirty-four studies were included. Twenty-eight studies had a low risk of bias, and six studies had amoderate risk of bias. In general, calcium silicate-based sealers had a lower cytotoxic and genotoxic potential than epoxy-resin based sealers.Conclusions: Based on the findings from in vitrostudies, calcium silicate-based sealers are less cytotoxic andgenotoxic than epoxy resin-based sealers

POSTOPERATIVE PAIN INCIDENCE AND INTENSITY FOLLOWING ROOT CANAL OBTURATION WITH BIOCERAMIC AND OTHER SEALERS: A SYSTEMATIC REVIEW WITH META-ANALYSIS

Aims: To investigate whether bioceramicsealers induce a lower incidence and intensity of postoperative pain compared to other sealers. Materials and Methods: Six electronic databases were searched for studies published up to April 2022, following the PICOS strategy: (P) adult patients undergoing root canal treatment or retreatment; (I) root canal filling using bioceramic sealer; (C) root canal filling using other types of sealers; (O) Primary: postoperative pain incidence and/or intensity; Secondary: number of medication intake; (S) randomizedclinical trials. Risk of bias assessment was performed with the revised Cochrane risk of bias tools for randomized trials (RoB 2). Overall certainty of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. Results: Ten studies were included. Eight studies had a low risk of bias, and two had some concerns risk. Meta-analyses showed no differences regarding postoperative pain intensity and incidence between bioceramic sealers and AH Plus. Number of medication intake seemed to be associated to the preoperative diagnosis. Zinc oxide-eugenol sealer demonstrated an intense postoperative pain compared to bioceramic sealers and AH Plus. GRADE analysis showed a low certainty of evidence for all outcomes. Conclusions: There seem to be no differences between bioceramic sealers and AH Plus regarding postoperative pain intensity and incidence. Number of medication intake seem to be associated to the preoperative diagnosis. Zinc oxide-eugenol evoked a more pronounced postoperative pain.

Toothbrushing effects on the surface roughness and cement volume loss of bonded enamel-ceramic interface

Abstract This study evaluated the effect of toothbrushing on enamel-cementing material-ceramic bonded interfaces, using different cementing materials. Materials and Methods: Thirty enamel and thirty ceramic blocks were bonded with cementing materials to produce the samples that were bonded with three types of cementing materials: 1- RelyX Ultimate resin cement (REXU), 2- RelyX Unicem 2 self-adhesive resin cement (REU2) and 3- heated Z100 restorative composite (60°C). Bonded interfaces of the samples were toothbrushed and the surfaces of the 3 cementing materials were evaluated for roughness (RG, in µm), roughness profile (RP, in µm), and volume loss (VL, in µm3) (baseline and after 20,000 and 60,000 toothbrushing cycles). Data were evaluated by Generalized Linear Analysis (two factors: "material" and "toothbrushing cycle") and Bonferroni test (α=0.05). Results: REXU and Z100 exhibited lower RG than that presented by REU2, except after 60,000 toothbrushing cycles when only Z100 differed from REU2. The increase in toothbrushing cycles increased the RG and RP for all materials. REU2 also showed higher RP than those showed by REXU and Z100 when it was analyzed regarding the enamel. The VL of Z100 was the lowest with 20,000 toothbrushing cycles, regarding the enamel and ceramic. For 60,000 cycles, REXU showed the lowest VL regarding the ceramic, and REU2 had the highest VL regarding the enamel and ceramic. Conclusion: In general, REXU and Z100 showed the best results regarding the evaluations performed and the REU2 exhibited the highest RG, RP, and VL.

Resumo Este estudo avaliou o efeito da escovação nas interfaces de união esmalte-material cimentante-cerâmica, utilizando diferentes materiais cimentantes. Materiais e Métodos: Trinta esmaltes e trinta blocos cerâmicos foram unidos com materiais de cimentação para produzir as amostras que foram unidas com três tipos de materiais de cimentação: 1- cimento resinoso RelyX Ultimate (REXU), 2- cimento resinoso autoadesivo RelyX Unicem 2 (REU2) e 3-compósito restaurador aquecido Z100 (60°C). As interfaces coladas das amostras foram escovadas e as superfícies dos 3 materiais cimentantes foram avaliadas quanto à rugosidade (RG, em µm), perfil de rugosidade (RP, em µm) e perda de volume (VL, em µm3) (baseline e após 20.000 e 60.000 ciclos de escovação). Os dados foram avaliados por Análise Linear Generalizada (dois fatores: "material" e "ciclo de escovação") e teste de Bonferroni (α=0,05). Resultados: REXU e Z100 apresentaram menor RG do que REU2, exceto após 60.000 ciclos de escovação, quando Z100 diferiu apenas de REU2. O aumento dos ciclos de escovação aumentou o RG e RP para todos os materiais. O REU2 também apresentou PR maior que o REXU e Z100, quando analisado em relação ao esmalte. O VL de Z100 foi o menor com 20.000 ciclos de escovação em relação ao esmalte e cerâmica. Para 60.000 ciclos, o REXU apresentou o menor VL em relação à cerâmica e o REU2 o maior VL em relação ao esmalte e à cerâmica. Conclusão: De maneira geral, REXU e Z100 apresentaram os melhores resultados nas avaliações realizadas e o REU2 apresentou os maiores RG, RP e VL..

Injectable Composite Resin Technique: An Alternative for Anterior Esthetic Restorations - Case Report / Técnica de Resina Compuesta Inyectable: Una Alternativa para Restauraciones Estéticas Anteriores - Reporte de Caso

This article aims to describe a clinical case of the use of the injectable restorative technique with composite resin in a patient with an esthetic complaint in the anterior teeth. Producing direct restorations in anterior teeth when performed with composite resin demands a long clinical time. Results often depend on the operator's ability to reproduce proper form, function, and esthetics. Lately, the versatility of composite resins has increased. As this material evolved, new techniques were introduced to simplify the restorative process and save time. The restorative technique with injectable fluid composite resin, in addition to delivering faster and with a certain ease, is capable of increasing the predictability of treatment results. However, it is known that flowable resins have lower wear resistance and color stability compared to conventional resins. Thus, a version of this material with a higher filler content in its composition was introduced to the market, to improve wear resistance and gloss retention. Long-term studies evaluating the use of low-viscosity resins are needed. The injectable technique can accurately reproduce the morphology obtained in the wax-up of the case, generating a satisfactory esthetic and functional result. Despite simplifying the fabrication of restorations when compared to the conventional technique, it is still necessary for the operator to have some experience and aptitude. The clinical time for the production of restorations has been considerably reduced. The material showed good flow, shine, and polish in the immediate result. However, the finishing and polishing of the restorations required a longer clinical period than usual and in the short- term follow-up, flaws in the gingival margins and a new finishing and polishing procedure were necessary. Therefore, the technique described in this article can be considered a restorative alternative, but it is still not able to replace the tradit ional method of making previous esthetic restorations.

Este artículo tiene como objetivo describir un caso clínico del uso de la técnica restauradora inyectable con resina compuesta en un paciente con una queja estética en los dientes anteriores. Producir restauraciones directas en dientes anteriores cuando se realizan con resina compuesta demanda un largo tiempo clínico. Los resultados a menudo dependen de la capacidad del operador para reproducir la forma, la función y la estética adecuadas. Últimamente, la versatilidad de las resinas compuestas ha aumentado. A medida que este material evolucionó, se introdujeron nuevas técnicas para simplificar el proceso de restauración y ahorrar tiempo. La técnica restauradora con resina compuesta fluida inyectable, además de una entrega más rápida y segura, es capaz de aumentar la previsibilidad de los resultados del tratamiento. Sin embargo, se sabe que las resinas fluidas tienen menor resistencia al desgaste y estabilidad del color en comparación con las resinas convencionales. Así, se introdujo en el mercado una versión de este material con un mayor contenido de relleno en su composición, con el objetivo de mejorar la resistencia al desgaste y la retención del brillo. Se necesitan estudios a largo plazo que evalúen el uso de resinas de baja viscosidad. La técnica inyectable es capaz de reproducir fielmente la morfología obtenida en el encerado del caso, generando un resultado estético y funcional satisfactorio. A pesar de simplificar la fabricación de restauraciones en comparación con la técnica convencional, todavía es necesario que el operador tenga cierta experiencia y aptitud. El tiempo clínico para la producción de restauraciones se ha reducido considerablemente. El material mostró buena fluidez, brillo y pulido en el resultado inmediato. Sin embargo, el acabado y pulido de las restauraciones requirió de un período de tiempo clínico más largo de lo habitual y en el seguimiento a corto plazo, fueron necesarios defectos en los márgenes gingivales y un nuevo procedimiento de acabado y pulido. Por lo tanto, la técnica descrita en este artículo puede considerarse una alternativa restauradora, pero aún no es capaz de reemplazar el método tradicional de realizar restauraciones estéticas previas.

Rendimiento Clínico de las Restauraciones Adhesivas con Resina Compuesta en Casos de Pacientes con Desgaste Severo e Incremento de Dimensión Vertical: Revisión de Literatura Sistematizada / Clínical Performance of Adhesive Restorations with Composite Resin in Cases of Patients with Severe Wear and Increased Vertical Dimension: Systematized Literature Review

El desgaste dental severo se describe como la pérdida sustancial de la estructura dental, con exposición de la dentina y pérdida significativa de igual o más de 1/3 de la corona clínica. El uso de materiales compuestos de resina permite al clínico ser más conservador, debido a su aplicación mínimamente invasiva. Además de ello, son relativamente económicas, proporcionan buena estética general, así como un buen rendimiento y facilidad en la reparación. El objetivo de esta revisión de literatura sistematizada es recopilar información disponible en la literatura referente a cuál es el rendimiento clínico de las restauraciones adhesivas con resina compuesta en casos de pacientes con desgaste severo e incremento de la dimensión vertical como objetivo rehabilitador. Se analizaron artículos entre los años 2000 y 2022, seleccionando cuatro bases de datos (Pubmed, Scopus, Scielo y Web of Science). Para identificar los descriptores se utilizó los Medical subject headings (Mesh): Tooth Wear, Composite Restorations, Resin y Oral Rehabilitation. No se aplicó restricciones de idioma, país de origen, autor o lugar de publicación donde se realizó el estudio. Como resultado de la búsqueda se obtuvieron 71 artículos, de los cuales se seleccionaron 5 que cumplieron con los criterios de elegibilidad para ser considerados en la revisión de literatura sistematizada. Se encontró un promedio de tasa de éxito ente el 89,4 % - 100 % en un promedio total de 5.2 años de seguimiento. Se puede concluir, hasta donde se tiene conocimiento en la literatura científica disponible, que el tratamiento de restauraciones adhesivas con resinas compuestas en pacientes con desgaste severo es recomendable, enfocado en un periodo a corto-mediano plazo (3-5 años), siendo una opción de tratamiento económica y mínimamente invasiva.

Severe tooth wear is described as the substantial loss of tooth structure, with dentin exposure and significant loss of equal to or more than 1/3 of the clinical crown. The use of resin composite materials allows the clinician to be more conservative, due to its minimally invasive application. In addition to this, they are relatively inexpensive, provide good general aesthetics, as well as good performance and ease of repair. The objective of this systematic literature review is to collect information available in the literature regarding the clinical performance of adhesive restorations with composite resin in cases of patients with severe wear and increase in the vertical dimension as a rehabilitation objective. Articles between the years 2000 and 2022 were analyzed, selecting four databases (Pubmed, Scopus, Scielo and Web of Science). To identify the descriptors, the Medical subject headings (Mesh) were used: Tooth Wear, Composite Restorations, Resin and Oral Rehabilitation. No language, country of origin, author or place of publication restrictions where the study was conducted were applied. As a result of the search, 71 articles were obtained, of which 5 were selected that met the eligibility criteria to be considered in the systematic literature review. An average success rate between 89.4 % - 100 % was found in a total average of 5.2 years of follow-up. It can be concluded, to the best of our knowledge in the available scientific literature, that the treatment of adhesive restorations with composite resins in patients with severe wear is recommendable, focused on a short-medium term period (3-5 years), being a Inexpensive and minimally invasive treatment option.

Degree of Conversion and Mechanical Properties of a Commercial Composite with an Advanced Polymerization System / Avaliação do grau de conversão e das propriedades mecânicas de um compósito comercial com sistema avançado de polimerização

ABSTRACT Advanced Polymerization System (APS) technology in a commercial composite resin enables reduction of the concentration of camphorquinone without altering composite physicochemical properties. Aim: The aim of this study was to evaluate the degree of conversion and mechanical properties of a commercial composite with an advanced polymerization system (APS) and compare it to other composites that do not use this system. Materials and Method: Five groups were analyzed. Group 1 (VT: Vittra APS - FGM); G2 (AU: Aura - SDI); G3 (ES: Quick Sigma Stelite - TOKOYAMA); G4 (FZ: Filtek Z350 XT - 3M ESPE); G5 (OP: Opallis -FGM). Degree of conversion (DC, n=3) was analyzed immediately and after 24h by analysis with FTIR spectroscopy. For Knoop hardness (KHN, n=3), 5 indentations were made at the top and bottom of specimens 2 mm thick. Flexural strength (FS, n=10) was determined by the three-point method in a universal testing machine. Polymerization stress (PS) was determined by light-curing the material (1.0 mm high) between polymethylmethacrylate rods in a universal testing machine. Light curing was performed with a Valo Cordless LED (1,000 mW/cm2 x 20 s: 20J). The results were analyzed using ANOVA and complemented by Tukey's test (α=0.05). Results: The highest DC values (immediate and 24h after) were observed for VT and OP resins, followed by FZ, AU and ES. FZ (top and bottom) had the highest KHN values, similar to VT top. AU, ES, OP and VT had statistically different KHN between their top and bottom surfaces. The highest RF values were observed for FZ, followed by OP/VT, ES and AU. The highest TP values were observed for FZ, OP and VT. Conclusion: The Vittra APS resin with a new polymerization system presents satisfactory performance for the parameters evaluated.

RESUMO A tecnologia Advanced Polymerization System (APS) presente em uma resina composta comercial permite reduzir a concentração de canforoquinona sem alterar as propriedades físico-químicas do compósito. Objetivo: o objetivo deste estudo foi avaliar o grau de conversão e as propriedades mecânicas de um compósito comercial com sistema avançado de polimerização (SAP) e comparálo com outros compósitos que não utilizam esse sistema. Materiais e Método: cinco grupos foram analisados. Grupo 1 (VT: Vittra APS - FGM); G2 (AU: Aura - SDI); G3 (ES: Quick Sigma Stelite - TOKOYAMA); G4 (FZ: Filtek Z350 XT - 3M ESPE); G5 (OP: Opallis -FGM). O grau de conversão (GC, n=3) foi analisado imediatamente e após 24h através da análise com espectroscopia FTIR; para dureza Knoop (DK, n=3), foram feitas 5 indentações no topo e na base de corpos de prova de 2 mm de espessura; para determinar a resistência à flexão (RF, n=10), o método de três pontos foi realizado em uma máquina universal de ensaios; a tensão de polimerização (TP) foi determinada pela fotopolimerização do material (1,0 mm de altura) entre hastes de polimetilmetacrilato em uma máquina de teste universal. A fotopolimerização foi realizada com um Valo Cordless LED (1.000 mW/cm2 x 20 s: 20J). Os resultados foram analisados por ANOVA e complementados pelo teste de Tukey (α=0,05). Resultados: os maiores valores de GC (imediato e 24h após) foram observados para as resinas VT e OP, seguidas de FZ, AU e ES. A resina FZ (superior e inferior) apresentou os maiores valores de DK, semelhante ao VT superior. As resinas AU, ES, OP e VT apresentaram DK estatisticamente diferente entre suas superfícies de topo e base. Os maiores valores de RF foram observados para FZ, seguido de OP/VT, ES e AU. Os maiores valores de TP foram observados para FZ, OP e VT. Conclusão: com base nos resultados, pode-se concluir que a resina Vittra APS com um novo sistema de polimerização apresenta desempenho satisfatório para os parâmetros avaliados.

In vitro cytotoxicity of resin cement and its influence on the expression of antioxidant genes / Avaliação in vitro da toxicidade de cimentos resinosos e sua influência na expressão de genes antioxidantes em fibroblastos humanos

ABSTRACT Aim: This study evaluated cytotoxicity and antioxidant gene expression of resin cements on human gingival fibroblasts (hGF). Materials and Method: RelyX Ultimate™(RXU), Variolink™II(VLII), and RelyXU200™(RXU200) resin cements were incubated with culture medium for 24 h to obtain eluates. Then, the eluates were applied over hGF to assess cell viability at 24 h, 48 h, and 72 h and antioxidant gene expression at 24 h. hGF cultures non-exposed to the eluates were used as Control. Data were submitted to ANOVA and Bonferroni tests (α≤0.05). Results: RXU and RXU200 reduced the number of viable cells in 24 h. Longer exposure to cement extracts caused cell death. Gene expression showed peroxiredoxin 1 (PRDX1) induction by all resin cement types, and superoxide dismutase 1 (SOD1) induction by RXU200 and VLII. Moreover, RXU200 induced not only PRDX1 and SOD1, but also glutathione peroxidase 1 (GPX1), catalase (CAT), and glutathione synthetase (GSS). Conclusions: All resin cements showed toxicity, and induced antioxidant genes in hGF. Antioxidant gene induction is at least partly associated with cytotoxicity of tested cements to oxidative stress experience.

RESUMO Objetivo: O objetivo deste estudo foi avaliar a toxicidade dos cimentos resinosos Rely X Ultimate 2, Rely X U200 e Variolink II, bem como sua influência na expressão de genes antioxidantes em fibroblastos gengivais humanos. Materiais e Método: Corpos de prova de cada cimento foram colocados em meio de cultura por 24 h e os extratos correspondentes foram aplicados aos fibroblastos. A viabilidade celular foi avaliada após 24, 48 e 72 h de exposição pelo ensaio de exclusão do azul de tripano e MTT. A expressão gênica foi avaliada por PCR quantitativo após 24 h de exposição aos extratos. Estes parâmetros foram comparados aos das células não expostas aos cimentos. Os dados foram submetidos ao teste ANOVA, seguido pelo pós-teste de Bonferroni (a≤0.05). Resultados: Os resultados demonstraram que todos os cimentos promoveram redução do número de células viáveis e da atividade mitocondrial nos períodos de 48 e de 72 h (p < 0,01), sendo que o Variolink II apresentou o menor efeito e os cimentos Rely X Ultimate e Rely X U200 promoveram similarmente os maiores efeitos. A análise de expressão gênica evidenciou influência significativa em todos os cimentos avaliados sobre os níveis de transcritos de PRDX1, SOD1, GPX1 e GSS (p> 0,05), com um aumento considerável no Rely X U200. Conclusão: A indução de genes antioxidantes está, pelo menos em parte, associada à citotoxicidade dos cimentos testados para a experiência de estresse oxidativo.

Evaluation of contact angle and mechanical properties of resin monomers filled with graphene oxide nanofibers

Abstract This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior.

Resumo Este estudo in vitro sintetizou nanofibras híbridas embebidas em óxido de grafeno (GO), incorporando-as à uma resina composta experimental de monômeros para avaliar suas propriedades físico-mecânicas. Nanofibras híbridas inorgânica-orgânicas foram produzidas com soluções precursoras de fibras poli (d, l-lactídeo, PLA) preenchidas com GO a 1% em peso e microscopia eletrônica de varredura (MEV) e espectroscopia de raio-X de energia dispersiva (EDS) caracterizaram a morfologia e composição química das fibras. Monômeros de resina composta foram desenvolvidos e um total de 5% de nanofibras foi incorporado aos materiais experimentais. Três grupos foram desenvolvidos: G1 (monômeros de resina controle), G2 (monômeros de resina/ nanofibras de PLA) e G3 (monômeros de resina/nanofibras híbridas inorgânico-orgânicas). Ângulo de contato (n=3), resistência à flexão (n=22), módulo de elasticidade (n=22) e dureza Knoop (n=6) foram avaliados. A média das três endentações foi obtida para cada amostra. A normalidade dos dados foi avaliada pelo QQ Plot com envelopes simulados e analisada pelo método de Welch (p<0,05). No geral, as imagens de MEV mostraram forma regular de nanofibras, mas não alinhadas. A análise composicional de EDS (n=6) revelou a presença de carbono e oxigênio (presentes na composição do GO) e Si resultante do processo de funcionalização. Os resultados do ângulo de contato (°) e dureza (Kg/mm2) para cada grupo foram os seguintes, respectivamente: G1 (59,65±2,90; 37,48±1,86a), G2 (67,99±3,93; 50,56±1,03b) e G3 (62,52±7,40; 67,83±1,01c). G3 apresentou os maiores valores de dureza Knoop (67,83 kg/mm2), e a resistência à flexão de todos os grupos foi prejudicada. A resina composta experimental composta por nanofibras híbridas com GO apresentou maiores valores de dureza e comportamento hidrofílico.

The effects of heating on the physicochemical properties of tricalcium silicate root canal sealers

Abstract This study evaluated the effect of heating on the physicochemical properties and surface changes of tricalcium silicate sealers. Three tricalcium silicate root canal sealers (Bio-C Sealer, BioRoot-RCS, EndoSequence BC Sealer), and one epoxy resin-based sealer (AH Plus; control) were tested. The effect of heating on setting time (ST) and flowability were assessed according to ANSI/ADA 57 and ISO 6876 standards. Solubility and dimensional change (DC) of the set sealers were evaluated at 24 hours and after 30 days; the pH of the water used in the DC testing was also measured. Tests were repeated with heated sealers in an oven at 100 °C for 1 min. SEM and EDS analysis were performed. Data were analyzed using One-Way ANOVA and Tukey post-hoc tests (α=5%). Heating decreased the ST for AH Plus and EndoSequence (p<0.05). Heating reduced flowability (p<0.05) and increased pH for AH Plus (p<0.05). The solubility of Bio-C (dried specimens) was not in accordance with the ANSI/ADA standard. The solubility of EndoSequence was significantly higher (p<0.05) when it was heated and dried after 30 days. DC of Bio-C (24 h and 30 days), BioRoot-RCS (30 days) and AH Plus (24 h and 30 days) were not in accordance with the standards. SEM and EDS analysis showed significant changes in sealer microstructure after heating. In conclusion, heating decreased the ST and increased the solubility of EndoSequence BC sealer. No significant changes in flowability, DC, and pH were identified for all three tricalcium silicate sealers after heat application. However, all sealers had significant surface changes.

Resumo Este estudo avaliou o efeito do aquecimento nas propriedades físico-químicas e nas alterações superficiais de cimentos de silicato tricálcico. Três cimentos endodônticos de silicato tricálcico (Bio-C Sealer, BioRoot-RCS, EndoSequence BC Sealer) e um cimento à base de resina epóxi (AH Plus) foram testados para avaliar o efeito do aquecimento no tempo de presa (TP) e escoamento de acordo com as normas ANSI/ADA 57 e ISO 6876. A solubilidade e alteração dimensional (AD) dos cimentos foram avaliadas após 24 horas e 30 dias. O pH da água usada no teste de AD também foi medido. Os testes foram repetidos com cimentos aquecidos em um forno a 100 °C por 1 min. Análises em MEV e EDS foram realizadas. Os dados foram analisados pelos testes de ANOVA-1 via e post hoc de Tukey (α=5%). O aquecimento diminuiu o TP para AH Plus e EndoSequence (p<0,05). O aquecimento reduziu o escoamento (p<0,05) e aumentou o pH do AH Plus (p<0,05). A solubilidade do Bio-C (amostras desidratadas) não estava de acordo com o padrão ANSI/ADA. A solubilidade da EndoSequence foi significativamente maior (p<0,05) quando aquecida e desidratada após 30 dias. As AD de Bio-C (24 h e 30 dias), BioRoot-RCS (30 dias) e AH Plus (24 h e 30 dias) não estavam de acordo com as normas ADA e ISO. A análise em MEV e EDS mostrou alterações significativas na estrutura dos cimentos após aquecimento. Em conclusão, o aquecimento diminuiu o TP e aumentou a solubilidade do cimento EndoSequence BC. Não foram identificadas mudanças significativas no escoamento, AD e pH para os cimentos de silicato tricálcico após aquecimento. Porém, todos os cimentos tiveram alterações significativas na superfície.

Surface Analysis of a Universal Resin Composite and Effect of Preheating on its Physicochemical Properties

Abstract This study was aimed at analyzing the surface properties of a universal resin composite and evaluating the effect of preheating on its physicochemical properties. Two commercial resin composites were used under two conditions: Filtek Universal Restorative (UR); UR preheated (URH); Filtek Supreme (FS) and FS preheated (FSH). The film thickness (FT) test (n = 10) was done using two glass slabs under compression. Flexural strength (FLS) and modulus (FLM) were evaluated using a three-point flexion test (n = 10). Polymerization shrinkage stress (PSS) was evaluated in a universal testing machine (n = 5). Gap width (GW) between composite and mold was measured in internally polished metallic molds (n = 10). The degree of conversion (DC) was evaluated by Fourier Transform Infrared spectroscopy (n = 3). The morphology of the filler particles was checked by scanning electron microscope (SEM) and EDX analysis. Surface gloss (SG) and surface roughness (SR) were evaluated before and after mechanical brushing (n = 10). The outcomes were submitted to 2-way ANOVA and Tukey's test (α = 0.05). Lower mean values of FT were observed for the preheated groups when compared to the non-preheated groups. URH and FSH showed higher mean values of FLS and FLM when compared with UR and FS. No differences were observed between groups in the PSS test. The GW was higher for the UR and FS groups when compared with URH and FSH. The DC was higher for preheated resin composites when compared to the non-preheated groups. The SR of the UR composite was higher than the FS after mechanical brushing, while the SG was higher for the FS groups. In conclusion, the universal resin composite tested generally presented similar physicochemical properties compared with the nanofilled resin composite and either similar or slightly inferior surface properties. The preheating improved or maintained all properties evaluated.

Resumo Neste estudo avaliou-se propriedades físico-químicas e de superfície de um compósito universal pré-aquecido e comparado a um compósito convencional. Foram utilizados dois compósitos comerciais: Filtek Universal Restorative (UR); UR pré-aquecido (URH); Filtek Supreme (FS) e FS pré-aquecido (FSH). O teste de espessura de película (EP) (n = 10) foi feito usando duas placas de vidro sob compressão. A resistência à flexão (RF) e o módulo flexural (MF) foram avaliados por meio do teste de flexão de três pontos (n = 10). A tensão de contração de polimerização (TCP) foi avaliada em uma máquina de teste universal (n = 8). A largura da fenda (LF) entre o compósito e o molde foi medida em moldes metálicos polidos internamente (n = 10). O grau de conversão (GC) foi avaliado por espectroscopia de infravermelho com transformada de Fourier (n = 3). A morfologia das partículas de carga foi observada em microscopia eletrônica de varredura (MEV) e sua composição em EDX. Brilho superficial (BS) e rugosidade superficial (RS) foram avaliados antes e após escovação mecânica (n=10). Os resultados foram submetidos à ANOVA 2-fatores e as médias comparadas pelo teste de Tukey (α = 0,05). Menores valores médios de EP foram observados para os grupos pré-aquecidos quando comparados aos grupos não pré-aquecidos. URH e FSH apresentaram maiores valores médios de RF e MF quando comparados com UR e FS. Não foram observadas diferenças entre os grupos no teste TCP. A LF foi maior para os grupos UR e FS quando comparados com URH e FSH. O GC foi maior para os compósitos pré-aquecidos quando comparados aos não pré-aquecidos. A RS do compósito UR foi maior que o FS após a escovação mecânica, enquanto o BS foi maior para os grupos FS. Em conclusão, o compósito universal testado geralmente apresentou propriedades físico-químicas semelhantes em comparação ao compósito nanoparticulado e propriedades de superfície semelhantes ou ligeiramente inferiores. O pré-aquecimento melhorou ou manteve todas as propriedades avaliadas.

Effect of elastomeric urethane monomer on physicochemical properties and shrinkage stress of resin composites

Abstract This study aimed to evaluate the effect of an elastomeric urethane monomer (Exothane-24) in different concentrations on physicochemical properties, gap formation, and polymerization shrinkage stress of experimental resin composites. All experimental composites were prepared with 50 wt.% of Bis-GMA and 50 wt.% of TEGDMA, to which 0 wt.% (control), 10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.% of Exothane-24 were added. Filler particles (65 wt.%) were then added to these resin matrixes. Ultimate tensile strength (UTS: n = 10), flexural strength (FS: n = 10), flexural modulus (FM: n = 10), hardness (H: n = 10), hardness reduction (HR: n = 10), degree of conversion (DC: n = 5), gap width (GW: n = 10), and polymerization shrinkage stress in Class I (SS-I: n = 10) and Class II (SS-II: n = 10) simulated configuration. All test data were analyzed using one-way ANOVA and Tukey's test (α = 0.05; β= 0.2). Exothane-24 in all concentrations decreased the H, HR, DC, GW, SS-I, and SS-II (p < 0.05) without affecting the UTS, and FS (p > 0.05). Reduction in FM was observed only in the Exothane 40% and 30% groups compared to the control (p < 0.05). Exothane-24 at concentrations 20% and 30% seems suitable since it reduced GW and polymerization SS without affecting the properties of the composite resins tested, except for H.

Resumo Este estudo teve como objetivo avaliar o efeito de um monômero elastomérico de uretano (Exothane-24) em diferentes concentrações em propriedades físico-químicas, formação de fenda e tensão de contração de polimerização de resinas compostas experimentais. Todos os compósitos experimentais foram preparados com 50% em peso de Bis-GMA e 50% em peso de TEGDMA, nos quais 0% (controle), 10%, 20%, 30% e 40% em peso de Exothane-24 foram adicionados. Partículas de carga (65% em peso) foram então adicionadas as matrizes resinosas. Resistência coesiva (RC: n = 10), resistência à flexão (RF: n = 10), módulo de flexão (MF: n = 10), dureza (D: n = 10), redução de dureza (RD: n = 10), grau de conversão (GC: n = 5), largura de fenda (LF: n = 10) e tensão de contração de polimerização em simulações de cavidades Classe I (TC-I: n = 10) e Classe II (TC-II: n = 10). Todos os dados do teste foram analisados usando one-way ANOVA e teste de Tukey (α = 0,05; β = 0,2). O Exothane-24 em todas as concentrações diminuiu a D, RD, GC, LF, TC-I e TC-II (p < 0,05) sem afetar o RC e RF (p > 0,05). A redução da MF foi observada apenas nos grupos Exothane 40% e 30% em relação ao controle (p < 0,05). O Exothane-24 nas concentrações de 20% e 30% pareceu ser adequado, pois reduziu LF e TC de polimerização sem afetar as propriedades das resinas compostas testadas, exceto para D.

Efeito dos diferentes tipos de polimento sobre a rugosidade de superfície de uma resina acrílica comercial quimicamente ativada: estudo in vitro / Effect of different types of polishing on the surface roughness of a chemically activated commercial acrylic resin: an in vitro study

Objetivo: avaliar in vitro o polimento sobre resina acrílica quimicamente ativada (RAQA), por meio da rugosidade de superfície (Ra). Materiais e Método: Foram confeccionadas 40 amostras de RAQA, com dimensões de 10 a 10 x 2 mm, e foram divididas em quatro grupos (n=10): ausência do acabamento (AA); Ausência de polimento (AP); Polimento químico (PQ); Polimento com borrachas siliconadas + Escovas (PM). Os espécimes foram avaliados no quanto a rugosidade média (Ra) antes e após o envelhecimento em água destilada em uma estufa por 60 dias. Três medições de Ra (µm), na horizontal foram realizadas e calculada uma média para cada espécime. Os dados foram analisados de forma descritiva e inferencial, ANOVA de medidas repetidas e teste de Tukey com nível de significância de 5%. Resultados: Inicialmente, o grupo AA teve os menores valores de Ra e o grupo AP os maiores valores de rugosidade, com média e desvio padrão respectivamente 0,17 (±0,11) e 0,52 (±0,10). Após o envelhecimento, o grupo AA teve as menores médias e o grupo PQ os maiores valores de Ra, sendo 0,38 (±0,20) e 1,33 (±0,32), respectivamente. Os resultados evidenciaram diferença estatística significante quando as amostras foram submetidas ao acabamento com brocas. Conclusão: A RAQA necessita de polimento após acabamento com brocas, uma vez que a ausência de polimento comprometerá a lisura de superfície do material.(AU)

Objective: to evaluate in vitro polishing on chemically activated acrylic resin (RAQA), using surface roughness (Ra). Materials and Method: 40 RAQA samples were made, measuring 10 to 10 x 2 mm, and divided into four groups (n=10): absence of finishing (AA); Lack of polishing (AP); Chemical polishing (PQ); Polishing with silicone rubbers + Brushes (PM). The specimens were evaluated for their average roughness (Ra) before and after aging in distilled water in an oven for 60 days. Three horizontal Ra (µm) measurements were taken and an average was calculated for each specimen. Data were analyzed descriptively and inferentially, using repeated measures ANOVA and Tukey test with a significance level of 5%. Results: Initially, the AA group had the lowest Ra values and the AP group the highest roughness values, with mean and standard deviation respectively 0.17 (±0.11) and 0.52 (±0.10). After aging, the AA group had the lowest averages and the PQ group the highest Ra values, being 0.38 (±0.20) and 1.33 (±0.32), respectively. The results showed a statistically significant difference when the samples were finished with drills. Conclusion: RAQA requires polishing after finishing with drills, as the lack of polishing will compromise the surface smoothness of the material.(AU)

Envelhecimento bucal precoce e suas consequências para a cavidade oral com foco em reabilitação com resina composta: relato de caso / Early oral aging and its consequences for the oral cavity focusing on rehabilitation with composite resin: case report

O envelhecimento bucal precoce apresenta cada vez uma maior incidência nos consultórios odontológicos e sua degradação aos tecidos orais exige uma atenção por parte do cirurgiãodentista devido ao seu alto grau de complexidade. Esse envelhecimento precoce é causado principalmente por hábitos parafuncionais, dieta ou ambos. Suas consequências são desgastes patológicos dos tecidos dentários, extrusão passiva, perda de dimensão vertical e comprometimento estético e funcional. Por conta disso, o presente estudo teve como objetivo realizar um relato de caso clínico em um paciente jovem e com queixa estética como consequência de hábitos parafuncionais, aonde foram realizados uma reabilitação oral envolvendo aumento da dimensão vertical de oclusão através de Table Tops sem desgastes dentários e restaurações estéticas, ambas com resina composta. Essa reabilitação devolveu a DVO da paciente, trazendo conforto, contatos estáveis, guias de desoclusão e satisfação estética e funcional por parte da paciente(AU)

Early oral aging has an increasing incidence in dental offices and its degradation to oral tissues requires attention from the dentist due to its high degree of complexity. This premature aging is mainly caused by parafunctional habits, diet, or both. Its consequences are pathological wear of dental tissues, passive extrusion, loss of vertical dimension and aesthetic and functional impairment. Because of this, the present study aims to carry out a clinical case report in a young patient with an aesthetic complaint as a result of parafunctional habits, where an oral rehabilitation was carried out involving an increase in the vertical dimension of occlusion through Table Tops without dental wear and aesthetic restorations, both with composite resin. This rehabilitation returned the patient's OVD, bringing comfort, stable contacts, disocclusion guides and aesthetic and functional satisfaction on the part of the patient(AU)

Resin cast in situ: A technique to demonstrate the vasculature of the Nervous system: In Goat Model

Background: As Anatomical education advances very rapidly, and at the same time, there is huge demand and scarcity of true biological models, mainly brain tissue. In this scenario, in 1977, Guther Von Hagens worked on plastics and experimented voraciously on diffusing various plastics into large specimens and ultimately succeeded and coined the term “Plastination”. This technique is very popular in Western countries as the latter greatly minimizes the health hazards due to formalin exposure while dealing with biological tissue. In continuation with the advancement of expensive plastination to cost-effective resin casting, especially studies over the complex structures like the brain and spinal cord. In This study, we emphasize the cost-effective Resin cast-insitu method to demonstrate the vasculature of the brain and spinal cord. Materials and Methods: After obtaining the prior permission, we collected the Five (5) Goat heads from the slaughterhouse. Following the standard dissection procedure over the neck region, identified and canulated the major neck vessels. Through the vessels normal saline water, formalin, and pigmented resin were administered and preserved the goat head using routine preservation technique. After 36 to 48 hours, the routine dissection was scheduled to expose the brain and upper spinal cord segments, and finding were captured and recorded. Results and Discussion: The specimens show good penetration of dye in the artery and veins, and it’s easy to appreciate and study the vasculature of the brain and upper spinal cord segments, including the Bastons plexus of veins. Conclusion: In comparison with regular silicon casting, resin casting is very cost-effective and long-lasting, with good penetration of the resin substance up to the capillary level. Furthermore, similar studies may be conducted using in combination with whole organ plastination using silicon and resin embedding.

Effect of sodium/calcium hypochlorite on adhesion and adaptation of fiber posts luted with a dual resin cement

Abstract This study aimed to evaluate the effect of different concentrations of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2] on the bond strength and adaptation of glass fiber posts luted with a dual-curing resin cement. Fifty decoronated premolars were sectioned 14 mm from the apex and endodontically treated. The root canal filling was partially removed. The specimens were divided into 5 groups (n=10) according to the irrigant for post space irrigation: 0.9% sodium chloride (NaCl), (control); 2.5% NaOCl; 5.25% NaOCl; 2.5% Ca(OCl)2; and 5.25% Ca(OCl)2. For each group, irrigation was performed with 5 ml of solution. Afterward, the posts were luted with a dual-curing resin cement. One slice from each third was obtained and submitted to the push-out test and failure modes analysis. An additional slice from the middle third was submitted to confocal images for analysis of adaptation failures (gaps). Two-way ANOVA, Tukey's post-hoc, Kruskal-Wallis with Bonferroni adjusted, and chi-square tests, analyzed data. The group treated with 5.25% NaOCl showed lower bond strength values and generated more cohesive failures compared to the control (p < 0.05). Bond strength decreased from coronal to apical in the post space (p < 0.001). The groups treated with NaOCl had the highest percentages of gaps compared to the control (p < 0.05). Regardless of concentration, Ca(OCl)2 did not influence the bond strength and the occurrence of gaps (P > 0.05). Ca(OCl)2 is a good option for irrigating the post space before luting a fiber post with a dual-curing resin cement.

Resumo Este estudo teve como objetivo avaliar o efeito de diferentes concentrações de hipoclorito de sódio (NaOCl) e hipoclorito de cálcio [Ca(OCl)2] na resistência de união e adaptação de pinos de fibra de vidro cimentados com um cimento resinoso dual. Cinquenta pré-molares tiveram suas coroas removidas, foram seccionados a 14 mm do ápice e tratados endodonticamente. A obturação do canal radicular foi parcialmente removida. Os espécimes foram divididos em 5 grupos (n=10) de acordo com o irrigante para irrigação do espaço do pino: cloreto de sódio 0.9% (NaCl), (controle); NaOCl 2.5%; NaOCl 5.25%; Ca(OCl)2 2.5%; e Ca(OCl)2 5.25%. Para cada grupo, a irrigação foi realizada com 5 ml da solução. Posteriormente, os pinos foram cimentados com um cimento resinoso dual. Uma fatia de cada terço foi obtida e submetida ao teste push-out e análise dos modos de falha. Um corte adicional do terço médio foi submetido a imagens confocais para análise de falhas de adaptação (gaps). Os dados foram analisados pelos testes ANOVA de duas vias, post-hoc de Tukey, Kruskal-Wallis com ajuste de Bonferroni e qui-quadrado. O grupo tratado com NaOCl 5.25% apresentou menores valores de resistência de união e gerou mais falhas coesivas em relação ao controle (p < 0.05). A resistência de união diminuiu de coronal para apical no espaço do pino (p < 0.001). Os grupos tratados com NaOCl apresentaram os maiores percentuais de gaps em relação ao controle (p < 0.05). Independentemente da concentração, o Ca(OCl)2 não influenciou a resistência de união e a ocorrência de gaps (P > 0.05). O Ca(OCl)2 é uma boa opção para irrigar o espaço do pino antes de cimentar um pino de fibra com um cimento resinoso dual.

Facetas diretas em resina composta utilizando o fluxo digital para planejamento: relato de caso / Direct facets in composite resin using digital flow for planning: case report / Facetas directas en resina compuesta utilizando flujo digital para planificación: reporte de caso

Introdução:O aprimoramento das resinas compostas nos últimosanos em associação com a difusão de informações nas redes sociais tornou as facetas diretas tratamentos populares na dentística restauradora. No entanto, são procedimentos que exigem ampla destreza manual e conhecimento técnico. O fluxo digital através doescaneamento, enceramento digital e prototipagem 3D para construção de guias tem se tornado uma excelente alternativa para aumentar a previsibilidade e aumentar a longevidade destes trabalhos. Objetivo:Descrever o protocolo de confecção de facetas diretas em resina composta, através de um relato de caso, utilizando como auxílio o planejamento digital para confecção de modelo 3D, guia de silicone e paredes palatinas. Descrição do Caso:Paciente do gênero masculino, 43 anos, queixava-se do formato dos seus dentes. Ao exame clínico percebeu-se desgaste dental nos incisivos centrais e linha do sorriso levemente invertida. Após duas sessões de clareamento de consultório com Peróxido de hidrogênio (35%) e mockup direto com resina composta, foi realizada a moldagem e escaneamento do modelo de gesso no laboratório. O enceramento digital foi aprovado, o modelo 3D foi impresso para confecção da guia de silicone. Com auxílio da guia foram executadas facetas diretas nos elementos 13, 12, 11, 21, 22 e 23. Conclusão:O fluxo digital pode ser uma alternativa viável para minimizar as falhas na confecção de facetas diretas em resina composta (AU).

Introduction:The improvement of composite resins in recent years, together with information disseminated on social media, has made direct veneers popular treatments in restorative dentistry. However, these procedures require significant manual dexterity and technical knowledge. Digital work flow using scanning, digital wax-up and 3D prototyping for the construction of guides has become an excellent alternative to increase predictability and the longevity of these procedures. Objective:Describe the manufacturing protocol for direct composite resin veneers, using a case report and digital to construct the 3D model, silicone guide and palatine walls. Case description:Male patient, 43 years old, complained of the shape of his teeth. Clinical examination revealed tooth wear on the central incisors and a slightly inverted smile line. After two whitening sessions with hydroigen peroxide (35%) and direct mockup with composite resin, the plaster model was molded and scanned in the laboratory. Digital wax-up was approved, and the 3D model was printed to manufacture the silicone guide. With the help of the guide, the direct veneers were applied to elements 13, 12, 11, 21, 22 and 23.Conclusions:Digital flow may be a feasible alternative to minimize manufacturing flaws in direct composite resin veneers (AU).

Introducción: La mejora de las resinas compuestas en los últimos años, y la difusión de información en las redes sociales, ha popularizado las facetas directas en los tratamientos en odontología restauradora. Sin embargo, son procedimientos que requieren demasiado destreza manual y conocimientos técnicos. El flujo digital usando escaneo, encerado digital y prototipado 3D para la construcción de guías se ha convertido en una excelente alternativa para aumentar la previsibilidad y la longevidad de estos procedimientos. Objetivo: Describir el protocolo para la realización de carillas directas en resina compuesta, a través de un reporte de caso, utilizando el planeo digital como ayuda para la realización de un modelo 3D, guía de silicona y paredes palatinas. Descripción del caso: Paciente masculino, 43 años, se quejó de la forma de sus dientes. El examen clínico reveló desgaste dental en los incisivos centrales y una línea de sonrisa levemente invertida. Después de dos sesiones de blanqueamiento en consultorio con peróxido de hidrógeno (35%) y maqueta directa con resina compuesta, el modelo de yeso fue moldeado y escaneado en el laboratorio. El encerado digital fue aprovado, el modelo 3D fue impreso para hacer la guía de silicona. Con la ayuda de la guía se realizaron carillas directas en los elementos 13, 12, 11, 21, 22 y 23. Conclusiones: El fluxo digital puede ser una alternativa viable para minimizar fallas en la fabricación de carillas directas en resina compuesta (AU).