Does cad software affect the marginal and internal fit of milled full ceramic crowns?

Abstract: Although the effects of different intraoral scanners, model scanners, and CAM units on the marginal and internal fitting of restorations have been investigated, the effects of CAD software in particular has not been evaluated. The marginal and internal fit of indirect restorations may vary according to the CAD software used, even when using the same intraoral scanner and milling machine. The purpose of this study was to evaluate the marginal and internal fit of milled full ceramic crowns designed with three different CAD systems. Eleven typodont maxillary first premolar teeth were prepared and scanned using a 3Shape TRIOS Intraoral Dental Scanner. The obtained STL scan data were exported and used to design a full crown using three different CAD systems (CEREC, KaVo, and Planmeca). An independent milling unit was used to manufacture the crowns for each group (n = 11). The marginal and internal fit were evaluated for each restoration using 2D and 3D micro-CT analysis. For 2D analysis, 18 measurements for each sample were made, covering the marginal (Marginal Gap Buccal (MG-A), Marginal Gap Palatinal (MG-B), Finish Line Buccal (FL-A), Finish Line Palatinal (FA-B)) and internal fit locations (Axial Wall Buccal (AW-A), Axial Wall Palatinal (AW-B), Lingual Cusp (LC), Buccal Cusp (BC), and Occlusal Central Fossa (OCF)). Statistical analyses were performed using Open Source R Statistical Software (α = 0.05) The results of Duncan's multiple range test showed that the values for the marginal measurement points MG-A, MG-B, FL-A, and FL-B in the Planmeca group were significantly higher than the values obtained in the CEREC and KaVo groups (p < 0.05). In AW1, values of the CEREC group were found to be higher than those of the KaVo and Planmeca groups (p < 0.05). CAD software showed an effect on the marginal fit values of crowns whereas no significant difference was observed in terms of the internal fit, except for a single measurement point made from the buccal direction.

Assessment of dental care during the COVID-19 pandemic in Turkey and future projections / Avaliação dos cuidados dentários durante a pandemia COVID-19 na Turquia e perspectivas

A new coronavirus disease has affected the whole world, starting from Wuhan, China at the end of 2019. The disease, caused by the pathogen of SARS-CoV-2, commonly called COVID-19, has soon passed into the history of epidemics as the most effective pandemic recently. Dentistry has also been significantly affected by the pandemic process, which had a restrictive effect on almost all aspects of social life. Dental treatments are healthcare services that have been applied very carefully in terms of the risk control of cross-infection prior to this pandemic where disinfection and sterilization rules continue to be controlled at the highest level. However, hand instruments used in most dental treatments and generating aerosol has raised concerns, particularly in diseases such as COVID-19, which increase the risk of droplet contamination. This working order is an important risk factor not only for healthcare professionals but also for the contamination of patients and the environment. In addition, the continuing pandemic process and the dynamics of the process require revision of the protocols. For this reason, each country has prepared protocols in order to maintain the dental treatments in the pandemic process in accordance with their own health care conditions and policies. This process caused the dental professionals to reconsider their routine working practices and prospectively, new protocols are recommended for dental applications. This article aims to provide a perspective evaluating the current situation and discuss additional measures to be considered during the pandemic and thereafter.(AU)

Uma nova doença por coronavírus afetou o mundo inteiro, a partir de Wuhan, China, no final de 2019. A doença, causada pelo patógeno da SARS-CoV-2, comumente chamada COVID-19, logo passou para a história das epidemias como a pandemia mais eficaz. A odontologia também foi significativamente afetada pelo processo de pandemia, que teve um efeito restritivo em quase todos os aspectos da vida social. Os tratamentos dentários são serviços de saúde que foram sempre aplicados com muito cuidado em termos de controle de risco de infecção cruzada mesmo antes desta pandemia, onde as regras de desinfecção e esterilização continuam a ser controladas ao mais alto nível. No entanto, as turbinas usadas na maioria dos tratamentos odontológicos que geram aerossóis têm suscitado preocupações, principalmente em doenças como a COVID-19, pelo aumento do risco de contaminação por gotículas. Essa mecânica de trabalho é um importante fator de risco não apenas para os profissionais de saúde, mas também para a contaminação dos pacientes e do ambiente. Além disso, o processo continuado da pandemia e sua dinâmica exigem revisão dos protocolos. Por esse motivo, cada país elaborou protocolos para manter os tratamentos dentários no processo de pandemia, de acordo com suas próprias condições e políticas de saúde. Esse processo levou os profissionais de odontologia a reconsiderar suas práticas de trabalho de rotina e, prospectivamente, novos protocolos são recomendados para aplicações odontológicas. Este artigo tem como objetivo fornecer uma perspectiva para avaliar a situação atual e discutir medidas adicionais a serem consideradas durante e após a pandemia.(AU)