Search

Face shields have been adopted worldwide as personal protective equipment for healthcare professionals during the COVID-19 pandemic. This device provides a transparent facial physical barrier reducing the exposure to aerosol particles. The fused deposition modeling (FDM) is the most applied process of additive manufacturing due to its usability and low-cost. The injection molding (IM) is the fastest process for mass production. This study is the first to perform a qualitative comparison between the use of FDM and IM processes for mass production and rapid distribution of face shields in a pandemic. The design of the face shield and tests were conducted in prototyping cycles based on requirements of medical, Brazilian standards, manufacturing, and production. The FDM face shields manufacturing was carried out by a volunteer network, and the IM manufacturing was carried out by companies. The volunteers produced 35,000 medical face shields through the FDM process with daily delivery to several hospitals. A total of 80,000 face shields was produced by the IM process and delivered to remote Brazilian regions. The mass production of 115,000 face shields protected health professionals from public hospitals in all states of Brazil. In a pandemic, both FDM and IM processes are suitable for mass production of face shields. Once a committed network of volunteers is formed in strategic regions, the FDM process promotes a fast daily production. The IM process is the best option for large scale production of face shields and delivery to remote areas where access to 3D printing is reduced.

Objectives: The aim of this study is to compare the mechanical characteristics of resins for 3D printers with the acrylic resins that have been used in Dentistry, according to the post-processing method. Materials and Methods: Using an SLA 3D printer (Form 2 – Formlabs, Massachusetts, USA), samples (discs) were produced with the printer’s resins, Dental SG®, Dental LT®, Clear®, and Grey®. Samples made of thermopolimerized and auto polymerized acrylic resins were produced as well (Gold Standart parameters). The Knoop Hardness (KH) tests were performed using microdurometer HMV-2 (Shimadzu, Kyoto, Japan). Results: The results showed the Dental SG resin presented the highest KH, compared with thermopolimerized acrylic resin, the Clear and Dental LT resins KH were compared with auto polymerized acrylic resin, and the non-post cured Grey resin (not for intraoral use), as well as the Dental LT resin, showed the lowest KH. Conclusions: Considering the hardness, the printer’s resins are comparable with the acrylic resins established, when the post-processing method is thoroughly followed. The absence of material’s post-processing reduce significantly the material’s hardness. Clinical relevance: Regarding the use of 3D printing in Dentistry, the development of materials adequate for the equipment, biocompatible for intraoral uses, and compatible mechanical proprieties are essential. Objetivos: O objetivo deste estudo é comparar as características mecânicas das resinas para impressoras 3D com as resinas acrílicas utilizadas em Odontologia, de acordo com o método de pós-processamento. Materiais e Métodos: Utilizando uma impressora SLA 3D (Form2 – Formlabs, Massachusetts, EUA), amostras (discos) foram produzidas com as resinas da impressora, Dental SG®, Dental LT®, Clear® e Grey®. Também foram produzidas amostras feitas de resinas acrílicas termopolimerizadas e autopolimerizadas (parâmetros Gold Standart). Os testes de dureza Knoop (KH) foram realizados usando o microdurômetro HMV-2 (Shimadzu, Kyoto, Japão). Resultados: Os resultados mostraram que a resina Dental SG apresentou o KH mais alto, em comparação com a resina acrílica termopolimerizada, as resinas Clear e Dental LT KH foram comparadas com a resina acrílica autopolimerizada e a resina Grey sem pós-cura (não para uso intraoral), assim como a resina Dental LT, apresentou o menor KH. Conclusões: Considerando a dureza, as resinas da impressora são comparáveis às resinas acrílicas, quando o método de pós-processamento é completamente seguido. A ausência do pós-processamento do material reduz significativamente a dureza do material. Relevância clínica: No que diz respeito ao uso da impressão 3D em Odontologia, o desenvolvimento de materiais adequados ao equipamento, biocompatíveis para usos intraorais e propriedades mecânicas compatíveis é essencial.

Digital workflow is an important tool in the development of intraoral appliances by additive manufacturing. The purpose of this article is to present a completely digital workflow that uses a free software program and a low-cost 3D printer to fabricate occlusal devices for managing temporomandibular dysfunction. Three-dimensional images were acquired of an open maxillomandibular relationship record by using a scanner. A free software program was used to design the devices, and a 3D printer was used to produce the appliances by using a biocompatible resin. An evaluation of the technique on 5 patients showed good internal fit of the 3D-printed device with a similar need for occlusal adjustment as conventionally fabricated occlusal devices.

Introduction: New technologies in dental practice, such as laser, have enabled new strategies to be established in dental education. The aim of this study was to analyze the difficulties that dental students encountered with performing surgical incisions using Er:YAG laser (LE), and the morphology of these incisions. Material and Methods: Sixteen undergraduate dental students and ten dental professionals (DP) enrolled at The Master of Science Program in Laser Dentistry were asked to perform 15 incisions using an LE and 15 with a conventional scalpel. The incisions were compared, based on the shape factor (relation between area and perimeter), which was obtained by a digital image system and by a morphometry software. Data was submitted to statistical analysis of variance (p 0.05). Results: Considering the incisions performed by scalpel, DP showed statistically significant differences (p < 0.01) in relation to control group (CG). Considering the LE, all groups showed significant differences (p