Comportamiento cromático de resinas acrílicas y bisacrílicas para restauraciones provisionales / Chromatic behavior of acrylic and bisacrylic resins used for provisional restorations

Introducción: Las prótesis provisionales son restauraciones usadas en prótesis fijas durante un tiempo, hasta la cementación de la prótesis definitiva. Uno de los problemas que presentan este tipo de restauraciones es el cambio de color, que afecta a la estética y, en consecuencia, produce sensación de desagrado en los pacientes. Objetivo: Evaluar, para restauraciones provisionales, con y sin el pulido final de la superficie, la estabilidad del color de dos resinas al ser sumergidas en café. Métodos: Estudio experimental in vitro, realizado en el Laboratorio de Prótesis de la Facultad de Odontología de la Universidad Nacional del Nordeste, Corrientes-Argentina, 2019. Se comparó una resina acrílica (Duralay®) con una bisacrílica (ProtempIV 3M®) para restauraciones provisionales. Se elaboraron 40 discos de resinas a partir de moldes metálicos de 25 mm de diámetro y 2 mm de espesor. Se utilizaron 20 discos para cada tipo de resina, de ellos, 10 pulidos y 10 sin pulir. Las muestras fueron almacenadas en agua destilada en estufa a 37 °C durante 24 h para hidratarlos. Luego se procedió a la toma del color. Con posterioridad, cada grupo se sumergió en café, manteniéndolos en estufa a 37 °C durante 24 h más. Seguidamente, se realizó la segunda toma del color. Se utilizó el colorímetro Kónica Minolta®, determinando la diferencia total de color ΔE. Para el análisis estadístico se utilizó ANOVA una vía y test de Tukey para identificar la diferencia entre grupos. Resultados: Se observó en el grupo de resina acrílica pulida una diferencia ΔE = 0,82 ± DS = 0,22 y de ΔE = 3,86 ± DS = 0,30 sin pulido. En el grupo de resina bisacrílica pulido se obtuvo ΔE = 4,84 ± DS = 0,25 y, para el no pulido, ΔE = 5,85 ± DS = 0,29. Conclusiones: Se comprobaron diferencias significativas en la estabilidad del color de ambas resinas. La resina bisacrílica fue la menos estable, independientemente del pulido(AU)

Introduction: Provisional prosthesis are restorations used in fixed prostheses for a while, until the definitive prosthesis is cemented. One of the problems posed by this type of restoration is the change in color, which affects esthetics and therefore creates a feeling of displeasure in patients. Objective: Evaluate, in the case of provisional restorations with and without final surface polish, the color stability of two resins when soaked in coffee. Methods: An in vitro experimental study was conducted in the Prosthesis Laboratory at the Dental School of the National University of the Northeast in Corrientes, Argentina, in the year 2019. A comparison was made of an acrylic resin (Duralay®) versus a bisacrylic resin (ProtempIV 3M®) for provisional restorations. Forty resin disks were made from metal molds 2 mm thick and 25 mm in diameter. Twenty disks were used for each type of resin, of which 10 were polished and 10 were not. The samples were stored in distilled water in a stove at 37ºC for 24 h to hydrate them. Color measurements were then taken. Next, each group was soaked in coffee and kept in the stove at 37ºC for another 24 h. A second color measurement was then taken. A Konica Minolta® colorimeter was used to determine total color difference ΔE. Statistical analysis was based on one-way ANOVA and Tukey's test was used to identify the difference between the groups. Results: In the polished acrylic resin group a difference was found of ΔE = 0.82 ± SD = 0.22, whereas in the non-polish group the difference was ΔE = 3.86 ± SD = 0.30. In the polished bisacrylic resin group the difference was ΔE = 4.84 ± SD = 0.25, whereas in the non-polish group the difference was ΔE = 5.85 ± SD = 0.29. Conclusions: Significant differences were found in the color stability of both resins. The bisacrylic resin was the least stable, regardless of polish(AU)

Influência do polimento e tipo de solução extrínseca na pigmentação de restaurações de resina composta / Influence of the dental polishing and type of extrinsic solution in the pigmentation of composite resin restorations

Objetivo: avaliar a pigmentação de restaurações de resina composta (RC) submetidas a diferentes métodos de polimento. Materiais e método: foram realizadas restaurações de RC classe V em 80 dentes bovinos, corpos de prova, divididos em dois grupos experimentais: G1, polimento com Ultra-Gloss, e G2, polimento com um sistema que utiliza uma ponta siliconada impregnada com abrasivo, Enhance. Após, todos os grupos experimentais foram submetidos a soluções pigmentantes de café, chimarrão e refrigerante, 2 vezes ao dia, por 5 minutos, num período de 15 dias. Os corpos de prova foram analisados pela coloração da RC através de um colorímetro utilizando o sistema CIE-Lab. Aplicou-se a análise de variância seguida do método de comparação múltipla de Tukey, quando observada diferença significativa entre os corpos de prova. Resultados: os resultados mostraram que houve diferença estatística nos valores de médios (valor-p < 0,05), sugerindo o café com variação mais elevada; também para as variações entre a condição experimental (valor-p < 0,05), com exceção de delta a (valor-p = 0,817). Conclusão: o tipo de método para polimento de restaurações em RC não apresenta associação significativa com a pigmentação do material, sendo que esta está relacionada com o tipo da solução corante e com o tempo de exposição do compósito às pigmentações. (AU)

Objective: to evaluate the pigmentation of composite resin restorations submitted to different polishing methods. Materials and method: Class V composite resin restorations were performed on 80 bovine teeth, specimens, and divided into two experimental groups: G1-polishing with Ultra-Gloss and G2-polishing with a system using a silicon tip impregnated with abrasive, Enhance. Afterwards, all the experimental groups were submitted to pigmenting solutions of coffee, chimarrão and refrigerante, 2 times a day, for 5 minutes, in a period of 15 days. The specimens were analyzed by coloring the composite resin using a colorimeter using the CIE-Lab system. The analysis of variance was applied followed by Tukey's multiple comparison method when a significant difference was observed between the test specimens. Results: The results showed that there was statistical difference in the mean values (p-value <0.05), suggesting coffee with the highest variation; (p-value <0.05), with the exception of delta a (p-value = 0.817). Conclusion: The type of method for polishing restorations in composite resin does not present a significant association with the pigmentation of the material, which is related to the type of the dye solution and the time of exposure of the composite to pigmentation. (AU)

Inorganic filler content of resin-based luting agents and the color of ceramic veneers

Abstract The influence of inorganic filler content of resin-based luting agents (RBLAs) on color change (ΔE00), CIEL*a*b* (individual color coordinates), and translucency parameters (TP) of simulated ceramic laminate veneer (CLV) was investigated. RBLAs with low, intermediate, and high inorganic filler content (55%, 65%, and 75% mass fractions, respectively) were prepared. Feldspar ceramic (Vitablocs Mark II) specimens (1.2 mm × 0.8 mm, A1C shade) were bonded to simulated composite resin substrates (1.6 mm × 1.2 mm, A2D shade) using three experimental and a commercial (RelyX Veneer) RBLA (translucent shade). The ΔE00 was calculated by CIEDE2000 color difference metric under three conditions (before, immediately after, and 24 h after luting). The TP was calculated using CIEL*a*b* color coordinates measured over white and black backgrounds. Surface morphology of the RBLAs was analyzed. One-way and two-way analyses of variance with a post-hoc Tukey's test were used respectively to calculate TP, CIEL*a*b* coordinates, and ΔE00 (α= 0.05). Overall, the tested RBLAs presented clinically visible ∆E00 values under the three conditions evaluated. For all RBLAs, higher ∆E00 values were observed between measurements obtained before and immediately after luting. Different inorganic filler content did not significantly increase the opacity of the ceramic-luting agents-resin composite set. The variation in inorganic filler content did not influence significantly the TP of simulated CLV; although all of the experimental RBLAs tested yielded ∆E00 above the perceptibility threshold. The L*, a*, and b* individual color coordinates were cementation-dependent.

Translucency and color stability of resin composite and dental adhesives as modeling liquids - A one-year evaluation

Abstract The aim of this study is to evaluate the influence of modeling liquids on the translucency and color shade of resin composites (RCs) after one year of storage. RC specimens were prepared using either a conventional insertion technique (control; without modeling liquid) or a restorative dental modeling insertion technique (RDMIT) with dental adhesives as modeling liquids (Scotchbond™ Multi-Purpose [SBMP; 3M ESPE] or Adper™ Single Bond 2 [SB; 3M ESPE]). The initial colors of the specimens were obtained with a digital spectrophotometer and the CIEL*a*b* color system, after which specimens were stored (37°C) in distilled water or red wine for 12 months. Color measurements were reassessed after 6 and 12 months of storage, and scanning electron microscopy was performed after 12 months. Translucency and color change (ΔE*) were calculated and analyzed using ANOVA and Tukey's test (α = 5%). RC samples prepared via RDMIT showed a translucency similar to that of control samples. ΔE* was also less intense for RCs containing SBMP than for RCs containing SB. Specimens stored in wine showed a clear pattern of degradation, especially in the control group, and surface degradation seemed to be less intense for specimens prepared with SBMP and SB than for specimens without. Specimens stored in water did not show clear evidence of surface degradation. RDMIT appears to be an interesting approach to reduce ΔE* in RCs over time without negative effects on the translucency of the material. However, the modeling liquid should feature a hydrophobic composition, similar to that used in the SBMP group, the achieve the best results.

Influence of resin cement shade on the color and translucency of ceramic veneers

ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable.

Effects of modeling liquid/resin and polishing on the color change of resin composite

Abstract Modeling liquids/resins have been used to build up resin composite (RC) restorations, although there is a lack of information regarding their effects on the color stability of the latter. Therefore, the purpose of the present study was to evaluate the effects of the presence of modeling liquid between layers of RC and the finishing/polishing state of the material on color change in specimens exposed to red wine staining over time. Specimens were prepared by placing four increments (±0.5 mm thick) of RC (Filtek™ Z350 XT, 3M ESPE) into molds; half of which were prepared by applying modeling liquid (Scotchbond™ Multi-Purpose™ Adhesive, SBMP, 3M ESPE) between the layers of RC, whereas the other half were prepared without SBMP (control). Light-activation was performed after application of the final RC layer using a light-emitting diode (Radii, SDI) curing unit with an irradiance of 900 mW/cm2 for 20 s. Each group was divided according to the surface finishing protocol (n = 7): nothing (non-polished) or polishing with Sof-Lex™/diamond paste (polished). Initial colors of the specimens were evaluated with a digital spectrophotometer and the CIEL*a*b* color system. The specimens were stored in wine (37°C) for 12 months, and the color measurements were reassessed after 4, 6, and 12 months of storage. Scanning electron microscopy (SEM) analysis was performed at the end. Data were analyzed using ANOVA and Tukey's test (α = 5%). The presence of SBMP resulted in lower overall color change of the RC as compared with the control. The non-polished specimens exhibited a significantly higher color change than the polished specimens. SEM images corroborated the previous findings. In summary, the use of modeling liquid between layers of RC shows potential for application to reduce or delay the staining process of RC over time. Moreover, polishing is essential to provide increased color stability of the RC restoration.

Evaluation of roughness and micromorphology of epoxy paint on cobalt-chromium alloy before and after thermal cycling

It has been suggested that the epoxy paint used to coat metal substrates in industrial electrostatic painting applications could also be used to mask metal clasps in removable dental prostheses (RDP). The purpose of this study was to evaluate both the influence of thermal cycling and the in vitro roughness of a surface after application of epoxy paint, as well as to assess the micromorphology of a cobalt-chromium (CoCr) based metal structure. Sixty test specimens were fabricated from a CoCr alloy. The specimens were separated into three groups (n = 20) according to surface treatment: Group 1 (Pol) - polished with abrasive stone and rubbers; Group 2 (Pol+Epo) - polished and coated with epoxy paint; Group 3 (Epo) - air-abraded with aluminum oxide particles and coated with epoxy paint. The surface roughness was evaluated before and after 1000 thermal cycles (5°C and 50°C). The surface micromorphology was verified by scanning electron microscopy (SEM). The two-way repeated measures ANOVA showed significant differences among surface treatments (p < 0.0001), but no difference was found before and after thermal cycling (p = 0.6638). The CoCr-based metal alloy surfaces treated with epoxy paint (Groups 2 and 3) were rougher than the surfaces that were only polished (Group 1). Thermal cycling did not influence surface roughness, or lead to chipping or detachment of the epoxy paint.

Estabilidade de cor de cimentos resinosos ativados de forma foto e dual em função de diferentes cores / Redox potencial of ascorbic acid after sodium hypochlorite deproteinization to root dentine with different adhesive systems

O objetivo deste estudo foi o de avaliar a estabilidade de cor de diferentes cores de cimento (transparente, claro, e escuro) polimerizados de forma foto (Choice 2 Bisco, Rely X Veneer - 3M ESPE) ou dual (Variolink II Ivoclar-Vivadent, All Cem FGM). Um espectrofotômetro (Easyshade - VITA) foi usado para medir a cor das amostras (n=6) imediatamente após a confecção do espécime, 7 dias, 30 dias e 90 dias após. Os valores médios de diferença de cor (ΔE) foram maiores para as cores transparente (ΔE = 4,41), seguido pelas cores claras (ΔE = 3,12) e escuras (ΔE = 3,25). Os valores médios de ΔE foram menores para os cimentos fotoativados (Choice 2 ΔE = 2,79; Rely X VeneerΔE = 3,49) em comparação com os cimentos duais (Variolink II ΔE = 3,60; All Cem ΔE = 4,48). Um aumento dos valores ΔE foram observados com o aumento dos períodos de tempo avaliados (7 dias ΔE = 2,79; 30 dias ΔE = 3,73; 90 dias ΔE = 4,25).

The aim of this study was to evaluate the color stability of different cement color (transparent, clear, and dark) of light-polymerized resin cement (Choice 2 - Bisco, Rely X Veneer - 3M ESPE) or dual-cured cement (Variolink II Ivoclar- Vivadent , All Cem - FGM). Spectrophotometer (Easyshade - VITA) was used to measure the color of samples (n = 6) immediately after preparation, 7 days, 30 days and 90 days. The mean color difference (ΔE) was higher for transparent colors (ΔE = 4,41), followed by light (ΔE = 3,12) and dark colors (ΔE = 3,25). The mean values of ΔE were lower for the light-polymerized resin cement (Choice 2 ΔE = 2,79; Rely X Veneer ΔE = 3,49) compared to the dual-cured cement (Variolink II ΔE = 3,60; All Cem ΔE = 4,48). An increase in ΔE values was observed with increasing periods of time (7 days ΔE = 2,79; 30 days ΔE = 3,73; 90 days ΔE = 4,25).

Estabilidade de cor de cimentos resinosos ativados de forma foto e dual em função de diferentes cores / Redox potencial of ascorbic acid after sodium hypochlorite deproteinization to root dentine with different adhesive systems

O objetivo deste estudo foi o de avaliar a estabilidade de cor de diferentes cores de cimento (transparente, claro, e escuro) polimerizados de forma foto (Choice 2 Bisco, Rely X Veneer - 3M ESPE) ou dual (Variolink II Ivoclar-Vivadent, All Cem FGM). Um espectrofotômetro (Easyshade - VITA) foi usado para medir a cor das amostras (n=6) imediatamente após a confecção do espécime, 7 dias, 30 dias e 90 dias após. Os valores médios de diferença de cor (ΔE) foram maiores para as cores transparente (ΔE = 4,41), seguido pelas cores claras (ΔE = 3,12) e escuras (ΔE = 3,25). Os valores médios de ΔE foram menores para os cimentos fotoativados (Choice 2 ΔE = 2,79; Rely X VeneerΔE = 3,49) em comparação com os cimentos duais (Variolink II ΔE = 3,60; All Cem ΔE = 4,48). Um aumento dos valores ΔE foram observados com o aumento dos períodos de tempo avaliados (7 dias ΔE = 2,79; 30 dias ΔE = 3,73; 90 dias ΔE = 4,25).

The aim of this study was to evaluate the color stability of different cement color (transparent, clear, and dark) of light-polymerized resin cement (Choice 2 - Bisco, Rely X Veneer - 3M ESPE) or dual-cured cement (Variolink II Ivoclar- Vivadent , All Cem - FGM). Spectrophotometer (Easyshade - VITA) was used to measure the color of samples (n = 6) immediately after preparation, 7 days, 30 days and 90 days. The mean color difference (ΔE) was higher for transparent colors (ΔE = 4,41), followed by light (ΔE = 3,12) and dark colors (ΔE = 3,25). The mean values of ΔE were lower for the light-polymerized resin cement (Choice 2 ΔE = 2,79; Rely X Veneer ΔE = 3,49) compared to the dual-cured cement (Variolink II ΔE = 3,60; All Cem ΔE = 4,48). An increase in ΔE values was observed with increasing periods of time (7 days ΔE = 2,79; 30 days ΔE = 3,73; 90 days ΔE = 4,25).

Clinical strategies for esthetic excellence in anterior tooth restorations: understanding color and composite resin selection

Direct composite resin restorations have become a viable alternative for patients that require anterior restorative procedures to be integrated to the other teeth that compose the smile, especially for presenting satisfactory esthetic results and minimum wear of the dental structure. Technological evolution along with a better understanding of the behavior of dental tissues to light incidence has allowed the development of new composite resins with better mechanical and optical properties, making possible a more artistic approach for anterior restorations. The combination of the increasing demand of patients for esthetics and the capacity to preserve the dental structure resulted in the development of different incremental techniques for restoring fractured anterior teeth in a natural way. In order to achieve esthetic excellence, dentists should understand and apply artistic and scientific principles when choosing color of restorative materials, as well as during the insertion of the composite resin. The discussion of these strategies will be divided into two papers. In this paper, the criteria for color and material selection to obtain a natural reproduction of the lost dental structures and an imperceptible restoration will be addressed.

Evaluation of the color stability of two techniquesfor reproducing artificial irides after microwave polymerization

The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials. OBJECTIVES: The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image) and submitted to microwave polymerization. MATERIAL AND METHODS: Forty samples were fabricated simulating ocular prostheses. each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05). RESULTS: Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization. CONCLUSION: The digital imaging technique for reproducing irides presented better color stability after microwave polymerization.

Color y características ópticas para restauraciones estéticas de dientes anteriores / Color and optical properties for esthetic restorations in anterior teeth

Las restauraciones estéticas de dientes fracturados del sector anterior con resinas compuestas consisten en un desafío estético, principalmente cuando se trata de un único incisivo central. El aumento en la demanda por parte de los pacientes de restauraciones estéticas con mínima intervención provocó un aumento en las restauraciones directas con resinas compuestas como solución a esa demanda. Sin embargo, la obtención de restauraciones biomiméticas con características ópticas, biológicas y mecánicas óptimas exige experiencia y conocimiento de materiales y de técnicas restauradores por parte de los clínicos. El objetivo de este trabajo es describir las propiedades del color y las características ópticas de los dientes anteriores para la realización de restauraciones estéticas junto con la presentación de un caso de fractura de un incisivo central superior restaurado con resina compuesta directa donde la forma, textura y color fueron fielmente reproducidos a partir de una secuencia detallada de estratificación y de técnicas de acabado/pulido

Esthetic restorations of dental fractures in the anterior segment with composite resins remain in a complex aesthetic challenge, mainly when it is about a single central incisor. Increased patient demand for aesthetic dentistry with minimal invasive procedures has resulted in the extensive use of direct composite resin restorations to overcome this challenge. However, the achievement of biomimetics restorations with optimal optical, biological and mechanical characteristics demands on clinicians experience and knowledge of materials and restorative techniques. The aim of this article is to describe color and optical properties of anterior teeth for esthetics restorations presenting a case of direct composite resin restoration of a single central incisor fractured where the shape, texture and color were faithfully reproduced following a step-by-step sequence of layering and finishing/polishing techniques

Ocular prosthesis: art meets science / Prótese ocular: a arte encontra a ciência

Objective: To describe a method of fabricating of ocular prosthesis. Discussion: The conventionalmethod of painting the iris region of a scleral prosthesis has been circumvented in this method. Fabricatingan ocular prosthesis by conventional methods requires painting the scleral region. Painting the cornealregion of the prosthesis is a tedious process. This article describes an easier, faster and a more aesthetictechnique of customizing an ocular prosthesis.

Objetivo: Descrever um método de fabricação de prótese ocular. Discussão: O método convencional de pintura(caracterização) da região da íris numa prótese escleral foi modifi cado neste método. A fabricação de prótese ocular pormétodos convencionais requer pintura da esclerótica. Pintar a região corneal da prótese é um processo tedioso. Esteartigo descreve uma maneira rápida, fácil e com resultados estéticos satisfatórios de customização de próteses oculares.

Color alteration of the paint used for iris painting in ocular prostheses

The purpose of this study was to assess color alteration of the paints used for iris painting in artificial eyes. Five disks of heat cured acrylic resin were confectioned by microwave energy for each paint analyzed, in a total of 40 specimens. Each specimen consisted of a colorless acrylic resin disk and another of equal size, of scleral white colored acrylic resin, with the painting interposed between the two disks. The specimens were submitted to an accelerated aging process in a chamber under ultraviolet radiation for 1,008 hours. To assess color variation, a reflective spectrophotometer was used. The results were statistically analyzed by ANOVA and the Tukey test (p < 0.05). All the paints underwent chromatic alteration. The oil paint presented the highest resistance to accelerated aging.

Assessment of flexural strength of two self-curing acrylic resins containing pigment

Aim: To assess the flexural strength of orthodontic acrylic resins from two different manufacturers (VIPI, OrtoCril versus Clássico, OrtoClas) by comparing pigmented resins to colorless ones. Methods: Resins of blue, yellow and green colors were studied. A total of 120 specimens were made and then divided into groups of 15 elements each, all having the same dimensions. Next, they were kept in aqueous medium until being subjected to mechanical testing. The flexural strength was tested in a universal test machine (EMIC DL 10000) in which the specimens were subjected to a gradual load until fracture occurred. Results: Pigmented resins had flexural strength values compatible with clinical use, being similar to those from colorless ones, except for OrtoClas green-colored and yellow-colored resins, which showed greater flexural strength. The OrtoClas green-colored resin was the most resistant to fracture (482.2 N), whereas the OrtoCril colorless resin was the least resistant (368.4 N). All OrtoClas resins showed higher strength values compared to OrtoCril resins of same color, except for the OrtoCril’s blue-colored resin, which presented higher flexural strength than that of the other trademark. Conclusions: The use of pigments seems to have no effect on decreasing the flexural strength of self-curing acrylic resins. Therefore, pigmented resins are compatible with clinical use.

Técnica de caracterizaçäo de bases de prótese utilizando fibras de lä acrílica / Denture bases characterization technique using acrylic wool fibers

Os autores apresentam uma técnica de pigmentaçäo intrínseca de bases de prótese através da incorporaçäo em camadas de fios de lä acrílica na resina de cura térmica. O método de caracterizaçäo utilizado reproduz a translucidez, a profundidade e os tons dos tecidos gengivais, tornando a base da prótese mais natural

Caracterizaçäo das bases das próteses removíveis total e parciais: parte II / Caracterization of the complete and partial removable prosthetics basic

Através desta pesquisa os autores desenvolveram uma metodologia para obtençäo de resinas acrílicas termopolimerizáveis nas cores mais semelhantes àquelas observadas na pigmentaçäo natural da mucosa bucal. Os materiais utilizados como pigmentos säo de baixo custo e facilmente encontrados nos próprios laboratórios de prótese. Desta forma, com a elaboraçäo de uma ampla escala de cores pretende-se que a prática de caracterizaçäo das bases de próteses totais e parciais removíveis se torne um procedimento rotineiro entre técnicos e cirurgöes-dentistas, resultando num melhor e mais completo atendimento aos anseios estéticos, tanto pelos pacientes como pelos profissionais

Caracterizaçäo das bases das próteses totais e parciais removíveis / Characterization of denture bases and removable partial prosthodontics

O objetivo deste trabalho foi analisar, com base na revisäo da bibliografia, as diversas técnicas desenvolvidas para caracterizaçäo da cor das bases de próteses totais e parciais removíveis e avaliar as diferentes formas de obtençäo de resinas nas cores mais semelhantes àquelas encontradas na pigmentaçäo natural da gengiva e da mucosa bucal