Viviane Maria Gonçalves de Figueiredo

Effects of porcelain thickness on the flexural strength and crack propagation in a bilayered zirconia system

Abstract Objective: This study evaluated the influence of porcelain (VM9, VITA Zahnfabrik, Germany) thickness on the flexural strength and crack propagation in bilayered zirconia systems (YZ, VITA Zahnfabrik, Germany). Material and Methods: Thirty zirconia bars (20.0x4.0x1.0 mm) and six zirconia blocks (12.0x7.5x1.2 mm) were prepared and veneered with porcelain with different thickness: 1 mm, 2 mm, or 3 mm. The bars of each experimental group (n=10) were subjected to four-point flexural strength testing. In each ceramic block, a Vickers indentation was created under a load of 10 kgf for 10 seconds, for the propagation of cracks. Results: The results of flexural strength were evaluated by One-way ANOVA and Tukeys test, with a significance level of 5%. The factor “thickness of the porcelain” was statistically significant (p=0.001) and the l-mm group presented the highest values of flexural strength. The cracks were predominant among the bending specimens with 1 and 2 mm of porcelain, and catastrophic failures were found in 50% of 3-mm-thick porcelain. After the indentation of blocks, the most severe defects were observed in blocks with 3-mm-thick porcelain. Conclusion: The smallest (1 mm) thickness of porcelain on the zirconia infrastructure presented higher values of flexural strength. Better resistance to defect propagation was observed near the porcelain/ zirconia interface for all groups. Higher flexural strength was found for a thinner porcelain layer in a bilayered zirconia system. The damage caused by a Vickers indentation near and far the interface with the zirconia shows that the stress profiles are different.

DISFUNÇÃO TEMPOROMANDIBULAR E O IMPACTO NA QUALIDADE DE VIDA: UMA REVISÃO DE LITERATURA

| Temporomandibular dysfunction has been frequent in the population, so chronic pain is directly related to the state of the quality of life; so it is necessary to understand the interference in the quality of life of individuals with the dysfunction. The objective of this study was to review the literature about quality of life of patients with temporomandibular dysfunction, emphasizing the different indexes to evaluate the quality of life. The databases for searching the literature were Pubmed, Bireme, Lilacs, Scielo. The keywords used in the literature search were epidemiology, temporomandibular joint disorders, quality of life, present in Health Desc. The literature reviewed was selected based on abstracts. The inclusion criteria were epidemiological and clinical studies; systematic review and meta-analysis; literature in portuguese and english; studies evaluating the TMD and quality of life indexes; while the exclusion criteria were literature review, clinical case, letter to the editor; literature addressing TMD and quality of life in children; studies that did not address the variables under study. The temporomandibular dysfunction according to the reviewed literature has an impact on the quality of life of the individual with dysfunction, several are the questionnaires to measure how much the TMD interferes in the daily activities of the patients, nevertheless the association of instruments is favorable to evaluate different categories as to quality of life of patients with dysfunction. Keyword: Epidemiology, Temporomandibular Joint Disorders, Quality of Life. Resumo | A disfunção temporomandibular tem apresentando-se frequente na população, assim dor crônica está diretamente relacionada com o estado da qualidade de vida do indivíduo; por isso se faz necessário compreender a interferência na qualidade de vida de indivíduos acometidos pela disfunção. Objetivou-se revisar a literatura sobre disfunção temporomandibular e a qualidade de vida dos portadores da mesma, enfatizando os diversos índices para avaliar a qualidade de vida. As bases de dados para busca da literatura foram Pubmed, Bireme, Lilacs, Scielo. As palavras-chaves usadas na busca da literatura foram Epidemiologia, Transtornos da Articulação Temporomandibular, Qualidade de Vida, presentes no Desc Saúde. A literatura selecionada para esta revisão foi selecionada com base nos resumos e abstracts. Os critérios de inclusão da literatura nesta seleção foram Estudos Epidemiológicos e Clínicos; Revisão Sistemática e Metanálise; Literatura em Português e Inglês; Estudos que avaliem a DTM e Índices de Qualidade de Vida; enquanto que os critérios de exclusão foram Revisão de Literatura, Caso Clínico, Carta ao Editor; Literatura que abordasse a DTM e Qualidade de Vida em Crianças; Estudos que não abordassem as variáveis em estudo. A disfunção temporomandibular conforme a literatura revisada apresenta impacto na qualidade de vida do indivíduo portador da disfunção, diversos são os questionários para mensurar o quanto a DTM interfere nas atividades diárias dos pacientes, no entanto a associação de instrumentos é favorável para avaliar diferentes categorias quanto a qualidade de vida dos pacientes com disfunção. Palavras-chave: Epidemiologia, Transtornos da Articulação Temporomandibular, Qualidade de Vida. Submetido 16/06/2017, Aceito 19/02/2018, Publicado 22/02/2018 J Dent Pub H, Salvador, 2018 Março;9(1):55-66 Como citar este artigo: Novaes LA, Dantas TSB, de Figueiredo VMG. Disfunção temporomandibular e o impacto na qualidade de vida: uma revisão de literatura. J Dent Pub H. 2018;9(1):55-66. Re vi sã o de li te ra tu ra

APLICAÇÃO DE ELEMENTOS FINITOS NA ODONTOLOGIA: UMA REVISÃO DE LITERATURA

| Objective: Objective is with this literature review to clarify the application of finite elements in dentistry. Method: A literature review was based on a specific and relevant literature, ie, scientific articles, theses and books on the theme. This literature has been conductedon the following platforms: PubMed, Google Acadêmico, SciELO and virtual libraries. Conclusions: Finite elements is a method to improve clinical practice, through a computational tool to tension and structural analyses in dental materials and orofacial structures.