ince bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning Electron Microscopy (SEM). Materials and Methods: Twenty intact human third molars extracted for orthodontic reasons were randomly divided into four groups (n=5) treated as follows: G1-storage in artificial saliva (control group); G2-four 30-minute applications of 35% carbamide peroxide (total exposure: 2h); G3-four 2-hour exposures to 35% carbamide peroxide (total exposure: 8h); G4-two applications of 35% hydrogen peroxide, which was light-activated with halogen lamp at 700mW/cm 2 during 7min and remained in contact with enamel for 20min (total exposure: 40min). All bleaching treatments adopted in this study followed the application protocols advised by manufacturers. Evaluation of groups submitted to 35% carbamide peroxide was carried out after two time intervals (30 minutes and 2 hours per session), following the extreme situations recommended by the manufacturer. Specimens were prepared for SEM analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were characteristic of an erosive process that took place on human enamel. Depression areas, including the formation of craters, and exposure of enamel rods could also be detected. Conclusion: Bleaching effects on enamel morphology were randomly distributed throughout enamel surface and various degrees of enamel damage could be noticed. Clinical significance: In-office bleaching materials may adversely affect enamel morphology and therefore should be used with caution. Uniterms: Hydrogen peroxide; Carbamide peroxide; Tooth bleaching.esde o aumento da popularidade de tratamentos clareadores, o interesse em se pesquisar os efeitos dos peróxidos nos tecidos dentais duros é crescente. Proposta: O objetivo deste trabalho foi conduzir uma análise qualitativa in vitro do esmalte dental humano após clareamento com agentes para consultório, por meio de Microscopia Eletrônica de Varredura (MEV). Material e métodos: Foram utilizados 20 terceiros molares humanos hígidos, extraídos por motivos ortodônticos, sendo aleatoriamente divididos em 4 grupos (n=5) e tratados da seguinte forma: G1-armazenamento em saliva artificial (grupo controle); G2-4 aplicações de peróxido de carbamida a 35% por 30 min (tempo total de aplicação: 2h); G3-4 aplicações de peróxido de carbamida a 35% por 2 h (tempo total de aplicação: 8h); G4-2 aplicações de peróxido de hidrogênio a 35%, que foi foto-ativado com lâmpada halógena a 700mW/cm 2 por 7 min e mantido em contato com o dente durante 20 min (tempo total de aplicação: 40min). A avaliação dos grupos submetidos ao clareamento ...
The purpose of this study was to compare the microhardness of four indirect composite resins. Forty cylindrical samples were prepared according to the manufacturer’s recommendations using a Teflon mold. Ten specimens were produced from each tested material, constituting four groups (n=10) as follows: G1 - Artglass; G2 - Sinfony; G3 - Solidex; G4 - Targis. Microhardness was determined by the Vickers indentation technique with a load of 300g for 10 seconds. Four indentations were made on each sample, determining the mean microhardness values for each specimen. Descriptive statistics data for the experimental conditions were: G1 - Artglass (mean ±standard deviation: 55.26 ± 1.15HVN; median: 52.6); G2 - Sinfony (31.22 ± 0.65HVN; 31.30); G3 - Solidex (52.25 ± 1.55HVN; 52.60); G4 - Targis (72.14 ± 2.82HVN; 73.30). An exploratory data analysis was performed to determine the most appropriate statistical test through: (I) Levene's for homogeneity of variances; (II) ANOVA on ranks (Kruskal-Wallis); (III) Dunn's multiple comparison test (0.05). Targis presented the highest microhardness values while Sinfony presented the lowest. Artglass and Solidex were found as intermediate materials. These results indicate that distinct mechanical properties may be observed at specific materials. The composition of each material as well as variations on polymerization methods are possibly responsibles for the difference found in microhardness. Therefore, indirect composite resin materials that guarantee both good esthetics and adequate mechanical properties may be considered as substitutes of natural teeth.
mbora as cerâmicas possuam alta resistência à compressão, apresentam friabilidade devido à sua baixa resistência à tração e, desta forma, possuem menor capacidade de absorver impactos. Este trabalho avaliou a tenacidade à fratura de diferentes sistemas cerâmicos, que refere-se à medida da habilidade de absorção da energia de deformação de um material friável. Foram confeccionados 30 corpos-de-prova em forma de discos (5mmx3mm) utilizando-se três diferentes materiais cerâmicos, os quais foram divididos em 3 grupos: G1-10 amostras confeccionadas com a cerâmica Vitadur Alpha (Vita-Zahnfabrik); G2-10 amostras confeccionadas com a cerâmica IPS Empress 2 (Ivoclar-Vivadent) e G3-10 amostras confeccionadas com a cerâmica In-Ceram Alumina (VitaZahnfabrik). Para a obtenção dos valores de tenacidade foi utilizada a técnica da indentação que se baseia na série de fissuras que se formam sob uma carga pesada. Foram realizadas 4 impressões por amostra, utilizado um microdurômetro (Digital Microhardness Tester FM) com uma carga de 500gf, durante 10 segundos. A análise estatística dos dados (Testes ANOVA de Kruskal-Wallis e Dunn), indica que a cerâmica In-Ceram Alumina apresentou valor mediano (2,96N/m 3/2 ), estatisticamente diferente do apresentado pela IPS Empress 2 (1,05N/m 3/2 ), enquanto que a cerâmica Vitadur Alpha apresentou valores intermediários (2,08N/m 3/2 ), sem diferenças estatísticas dos outros dois materiais. Conclui-se que as cerâmicas apresentam diferentes desempenhos de tenacidade à fratura, sendo a In-Ceram capaz de absorver maior energia comparada a Vitadur Alpha e ao IPS Empress2. UNITERMOS: Cerâmicas odontológicas; Tenacidade à fratura; Método da indentação.
Em função da atual exigência estética por parte dos pacientes e profissionais, novos materiais e técnicas têm sido desenvolvidos para que o resultado final das restaurações seja cada vez mais semelhante ao dente natural. Dentro deste contexto, a translucidez é uma das características mais difíceis de serem reproduzidas pelos materiais restauradores estéticos diretos. Por ser uma propriedade característica do esmalte encontram-se hoje no mercado resinas compostas específicas para a substituição desta estrutura. Assim, este trabalho tem como objetivo estudar comparativamente os diferentes níveis de translucidez das resinas compostas A110 e Durafill (A1, A2 e A3) e Vitalescence (TM, TY, TI, TS, TA, TG), com a translucidez de corpos-de-prova de esmalte. Pôde-se observar que todas as cores da resina composta Vitalescence apresentaram valores de translucidez muito acima dos valores encontrados para o esmalte e para as demais resinas, enquanto que as resinas compostas A110 e Durafill apresentaram valores estatisticamente semelhantes entre si e ao esmalte, com exceção para a cor A1 da resina Durafill, que se apresentou ligeiramente menos translúcida.
This study histologically evaluated the behavior of bone tissue of rats submitted to osteotomy with conventional diamond burs in high speed and a new ultrasonic diamond tips system (CVD – Chemical Vapor Deposition), at different study periods. The study was conducted on 24 Wistar rats. Osteotomy was performed on the posterior paws of each rat, with utilization of diamond burs in high speed under thorough water cooling at the right paw, and CVD tips at the left paw. Animals were killed at 0, 7, 14 and 21 days after treatment, followed by removal of connective tissue and bone at the area of osteotomy. Specimens were fixated, demineralized, dehydrated and sectioned for histological analysis by polarized light microscopy (25, 100 and 200x magnification) by two examiners. The results demonstrated that there were no differences in the repair of bone defects between the two different materials employed for osteotomy.
Introdução: O traumatismo dental, além de alterações imediatascomo a fratura e o deslocamento do dente, pode provocar alteraçõesdo tipo: necrose ou calcificação distrófica. A calcificação distrófica éuma resposta pulpar ao trauma caracterizada pela deposição de tecidoduro no espaço pulpar geralmente acompanhada de alteraçõescromáticas do dente, provocando uma desarmonia do sorriso. Objetivo:O relato de caso aqui apresentado descreve a resolução estéticaem dentes com calcificação distrófica da polpa através de laminadoscerâmicos em associação ao clareamento dentário externo. Relatode caso clínico: Paciente do gênero masculino, 41 anos, apresentoucomo queixa principal a estética do seu sorriso devido a trauma nainfância. Ao exame clínico os dentes 11 e 21 exibiam coloração muitoescurecida em relação aos adjacentes, sem manifestar nenhuma respostaao teste de sensibilidade pulpar. Radiograficamente foi observadauma imagem sugestiva de obliteração total da câmara pulpar e doscanais radiculares com ausência de lesão periapical, sendo diagnosticadacomo calcificação distrófica da polpa. O tratamento proposto foio clareamento externo dos elementos dentários pela técnica combinada,devido a severidade do escurecimento, seguido pela instalaçãode laminados cerâmicos nas unidades comprometidas. ConsideraçõesFinais: A reabilitação em dentes com calcificação distrófica, porapresentar quase sempre um desafio no tratamento clínico, deve sercriteriosamente planejada e executada para a obtenção do sucesso.Diante do resultado obtido observou-se harmonia e evidente satisfaçãodo paciente.ABSTRACTIntroduction: In addition to immediate changes such as fracture andtooth dislocation, dental trauma can cause changes such as necrosisor dystrophic calcification. Dystrophic calcification is a pulp responseto trauma characterized by the deposition of hard tissue in the pulpspace usually accompanied by chromatic changes of the tooth, causinga smile disharmony. Objective: The case report presented here describesthe esthetical resolution in teeth with dystrophic calcificationof the pulp throught the ceramic laminates in association with externaldental whitening. Case report: Patient, male gender, 41 years old, presentedas main complaint the aesthetics of his smile due to trauma in
Objective: The purpose of this study was to assess the effects of laser irradiation and self-etching primer on the microleakage of apicoectomized teeth retro filled with mineral trioxide aggregate (MTA). Materials and Methods: A total of 60 bovine teeth were endodontically treated and had the apical 3 mm resected. Root-end cavities were prepared and the specimens were divided into five groups: Group 1 -control group, teeth only retrofiled with MTA; Group 2 -specimens treated with neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on the inner walls of the root-end cavities; Group 3 -specimens treated as Group 2 added with Nd: YAG laser on the surface of the apical resection; Group 4 -teeth treated with self-etching primer on the inner walls of the root-end cavities, and Group 5 -teeth treated as Group 4 and in addition, treated with self-etching primer on the surface of the apical resection. All the specimens were retrofiled with MTA and sealed with varnish. The teeth were immersed in 2% rhodamine B dye for 24 h. After this period, roots were washed, dried and resected. Marginal microleakage at material/root surface interface was evaluated quantitatively through linear measure in mm with the aid of a steromicroscope and calculated by an image program. Results:The mean values obtained were: Group 1 -2.76 ± 0.60; Group 2 -2.30 ± 0.84; Group 3 -2.21 ± 0.85; Group 4 -1.04 ± 0.76, and Group 5 -0.84 ± 0.40. ANOVA showed a significant difference among the groups (P < 0.05) and Tukey's test revealed that Group 1, Group 2 and Group 3 were different from Group 4 and Group 5. Conclusion: It was concluded that groups that used self-etching primer presented significantly lower degrees of marginal microleakage. Teeth treated with Nd: YAG laser presented same results as control group. The area of application did not reduce marginal leakage (for both laser and self-etching primer). Only MTA as a retro filling material was not sufficient to prevent marginal microleakage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.