Rosângela Marques Duarte

30-Month randomised clinical trial to evaluate the clinical performance of a nanofill and a nanohybrid composite

OBJECTIVE To evaluate the clinical performance of a nanofill and a nanohybrid composite in restorations in occlusal cavities of posterior teeth in a randomised trial over 30 months. METHODS Forty-one adolescents participated in the study. The teeth were restored with a nanofill (Filtek Z350, 3M ESPE), a nanohybrid (Esthet-X, Dentsply); Filtek Z250 (3M ESPE) was used as a control. After 30 months, the restorations were evaluated in accordance with the US Public Health Service (USPHS) modified criteria. The McNemar and Friedman tests were used for statistical analysis, at a level of significance of 5%. RESULTS There were significant differences in the roughness of Filtek Z250 (p=0.008) and Filtek Z350 (p<0.001) when the four time periods (baseline, 6 months, 12 months and 30 months) were compared. There were significant differences in the marginal adaptation of Filtek Z250 (p=0.001), Filtek Z350 (p<0.001) and Esthet-X (p=0.011). Except for one of each composite restoration, all the modifications ranged from Alpha to Bravo. There were significant differences in the surface roughness (p=0.005) when the three composites were compared after 30 months. CONCLUSIONS The materials investigated showed acceptable clinical performance after 30 months. Long-term re-evaluations are necessary for a more detailed analysis of these composites (CEP: #1252).

Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions

Purpose This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. Materials and Methods Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukeys test (p<0.05), considering the material factor and then the radiographic method factor, individually. Results The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. Conclusion The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

Nanohybrid versus nanofill composite in class I cavities: Margin analysis after 12 months

This study evaluates the margin of a nanofill, a nanohybrid, and a conventional microhybrid composite in restorations in occlusal cavities of posterior teeth after 12 months. Forty‐one patients, each with three molars affected by primary caries or the need to replace restorations, participated in this research. The teeth were restored with a nanofill (Filtek Z350), a nanohybrid (Esthet‐X), and a microhybrid as a control (Filtek Z250). Ten patients were selected randomly, and the three restorations were molded with a low‐viscosity polyvinyl siloxane material. The molds were poured with epoxy resin, gold‐sputter coated, observed by scanning electron microscopy, and classified as: “perfect margin,” “marginal irregularity,” “marginal gap,” “marginal fracture,” or “artifact.” For statistical analysis, the Wilcoxon and Friedman nonparametric tests and paired‐samples t‐test were used (significance level of 5%). The performance of the three materials was compared after 1 week and 12 months. No statistically significant differences were detected for all criteria (P > 0.05). When each composite was compared over time, statistically significant differences were found for the criterion, perfect margins (Esthet‐X and Filtek Z350, P < 0.05). The materials performed satisfactorily over the 12‐month‐observation period, but all composites under investigation showed a certain amount of deterioration relating to marginal quality over time. Microsc. Res. Tech. 74:23‐27, 2011.

Water sorption and solubility of glass ionomer cements indicated for atraumatic restorative treatment considering the time and the pH of the storage solution

Objective Evaluate the water sorption and the solubility of glass ionomer cements considering the time and the pH of the storage solution. Methods The materials used in this survey study were the following ones: Ketac Molar Easymix, Maxxion R, Vitro Molar, Vitremer and Vitro Fil LC. Fifteen specimens of each material were fabricated and subdivided into the storage solutions (deionized water, acid artificial saliva and neutral artificial saliva), having the mass measured in 24 hours, 7, 14 and 21 days. Water sorption and solubility values (μg/mm3) were obtained and submitted to the analysis of variance (ANOVA) and the Tukey test (p <0.05). Results The water sorption values were statistically different for all the studied materials and solutions in each storage period, except for the Maxxion R. Considering the solubility, all the glass ionomer cements presented values that were not statistically different when evaluating the storage solutions, except for the Vitro Fill LC. Conclusion The water sorption and the solubility of the studied glass ionomer cements were not influenced by the various storage solutions. Indexing terms: Glass ionomer cements. Hydrogen ion concentration. Solubility.

Bond Strength and Cytotoxicity of a Universal Adhesive According to the Hybridization Strategies to Dentin

This study evaluated application protocol (etch-and-rinse/ER and self-etching/SE) and dentin wettability (wet and dry) on microtensile bond strength (μTBS) and transdentinal cytotoxicity of ScotchbondTM Universal (SU) adhesive system. The μTBS values and fracture mode were registered 24 h after adhesive system application and resin composite block build-up (n=5). For analysis of transdentinal cytotoxicity, odontoblast-like MDPC-23 cells were seeded on pulpal surface of dentin discs (0.4 mm thick) adapted to artificial pulp chambers (n=8). The adhesive system was applied to occlusal surface, followed by 24-h incubation time. Cell viability (Alamar Blue) and morphology (SEM) were assessed. Adper Single Bond 2 and Clearfil SE Bond were used as positive controls of the ER and SE application protocols, respectively. No treatment was performed on negative control (NC) group. Data were analyzed by ANOVA and Tukeys tests (α=5%). Higher μTBS values were found for ER mode in comparison with SE protocol (p<0.05). Dentin wettability had no effect on bond strength of SU in both the ER and SE techniques (p>0.05). Most fractures involved hybrid layer and/or adhesive layer. Neither variable prevented the intense toxic effects of adhesive systems on MDPC-23 cultured cells, since intense reduction in cell viability (±88%) and severe alterations in cell morphology were observed for all groups compared to NC, with no differences among them (p>0.05). Therefore, it was concluded that application of SU following the ER protocol had better adhesive performance. However, this adhesive system featured intense transdentinal cytotoxicity to pulp cells, regardless of application protocol and dentin wettability.

Avaliação da rugosidade superficial e análise morfológica de cimentos de ionômero de vidro: influência do armazenamento em saliva artificial

Introducao O desenvolvimento dos cimentos de ionomero de vidro (CIVs) proporcionou vantagens aos procedimentos restauradores diretos devido a suas propriedades, como adesao quimica a estrutura dentaria e liberacao de fluor. No entanto, o ambiente bucal pode promover condicoes capazes de alterar a superficie deste material. Objetivo Avaliar a rugosidade superficial e a morfologia de superficie de quatro cimentos de ionomero de vidro (Ketac Molar Easy Mix, Vitremer, Vitro Molar e Maxxion), quando imersos em diferentes solucoes de saliva artificial. Material e metodo Dez amostras de cada material foram confeccionadas e a rugosidade superficial foi avaliada antes e apos imersao em saliva artificial acida e neutra, durante 28 dias, por meio de um rugosimetro (Surftest SJ - 40), e a analise morfologica deu-se atraves de microscopia eletronica de varredura. Os valores medios de rugosidade foram submetidos aos testes de Kruskal-Wallis e de Wilcoxon, alem do teste de Mann Whitney, com nivel de significância de 5%. Resultado Os valores de rugosidade foram maiores estatisticamente apos a imersao em saliva acida e neutra para todos os materiais, exceto o Vitromolar, que nao apresentou diferenca estatistica entre as medias de rugosidade antes e apos imersao em saliva neutra. O Maxxion R apresentou estatisticamente maiores valores de rugosidade quando comparado aos outros materiais apos imersao em saliva neutra e acida. Conclusao A rugosidade superficial dos cimentos de ionomero de vidro aumentou apos imersao em saliva neutra e acida para a maioria dos cimentos estudados. A solucao de armazenagem acida promoveu aumento da rugosidade superficial para o Maxxion R e o Vitro Molar.

AMELOGÊNESE IMPERFEITA: RELATO DE UMA REABILITAÇÃO ESTÉTICA CONSERVADORA

Objective: The aim of this study was to report a case of an aesthetic rehabilitation in a patient with amelogenesis imperfecta, who was treated with the use of the enamel microabrasion technique associated with composite resin. Case Report: An 18-year-old female patient was admitted to the Dental Clinic of the Federal University of Paraiba in need of aesthetic treatment in her maxillary anterior teeth. After anamnesis and detailed clinical examination, the patient was diagnosed with amelogenesis imperfecta. The enamel microabrasion technique in association with composite resin was proposed to restore the dental areas showing loss of substance. The stains were minimized by the enamel microabrasion technique using a mixture of 37% phosphoric acid and pumice stone, followed by fluoride topical application. In order to achieve a better aesthetic result, increments of composite resin were used in the areas that showed enamel slope. The enamel was etched with 37% phosphoric acid for 30 seconds, rinsed for 15 seconds, and dried with tissue paper. Then conventional adhesive was applied and light-cured for 20 seconds, followed by incremental application of composite resin (nanofilled composite resin, EA3). Conclusion: Enamel microabrasion was an effective technique to minimize stains. When associated with the use of composite resin, aesthetic recovery of the affected teeth was observed. DESCRIPTORS Enamel Microabrasion. Imperfecta Amelogenesis. Composite Resins. Dental Aesthetic.

OTIMIZANDO A ESTÉTICA DO SORRISO ATRAVÉS DE COROA CERÂMICA “METAL FREE” - RELATO DE CASO

Introduction: The permanent search for natural attributes in restorative procedures has played a major role in the development of new restorative materials and techniques. Crowns made of ceramic materials that are totally pure (“metal-free”) have been revealed to be an excellent restorative alternative, with aesthetic potential superior to that of metal-ceramic crowns. Objective: Through the analysis of a specific case study, this work aims to describe the different stages followed in the preparation of an anterior crown made of pure ceramic with the purpose of recovering smile aesthetics. Case report: The patient sought dental care complaining of the color and texture of upper central incisor, which had impaired dental aesthetics. The clinical and radiographic examinations revealed adequate endodontic treatment with presence of prefabricated fiberglass pin already cemented. After planning, it was decided to prepare the dental element and use a pure ceramic (“metal-free”) crown. Conclusion: Metal-free ceramic crowns are an excellent alternative technique allowing for aesthetics restoration in individuals unhappy with their smiles. DESCRIPTORS Ceramics. Esthetics. Dental. Dental Prosthesis.