Egas Moniz Interdisciplinary Research Center

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Suitability of 3D printed pieces of nanocrystalline zirconia for dental applications

Publication . Branco, A. C.; Silva, R.; Santos, T.; Jorge, H.; Rodrigues, A. R.; Fernandes, R.; Bandarra, S.; Barahona, I.; Matos, A. P. A.; Lorenz, K.; Polido, M.; Colaço, R.; Serro, A. P.; Figueiredo-Pina, C. G.

Objectives: The main goal of this work is to evaluate the suitability of nanostructured zirconia pieces obtained by robocasting additive manufacturing (AM), for dental applications. Methods: The density, crystalline structure, morphology/porosity, surface roughness, hardness, toughness, wettability and biocompatibility of the produced samples were compared with those of samples obtained by conventional subtractive manufacturing (SM) of a similar commercial zirconia material. Chewing simulation studies were carried out against dental human cusps in artificial saliva. The wear of the material was quantified and the wear mechanisms investigated, as well as the influence of glaze coating. Results: AM samples, that revealed to be biocompatible, are slightly less dense and more porous than SM samples, showing lower hardness, toughness and wettability than SM samples. After chewing tests, no wear was found both on AM and SM samples. However, the dental wear was significantly lower when AM samples were used as counterbody. Concerning the glazed samples, both coated surfaces and dental cusps suffered wear, being the cusps’ wear higher than that found for unglazed samples. More, cusps tested against AM coated samples suffered less wear comparatively to those opposed to SM coated samples. Significance. Overall, the results presented in this paper show that AM processed nanostructured zirconia can be used in dental restorations, with important advantages from the point of view of processing and tribological performance. Moreover, the option for glaze finishing should be carefully considered both in SM and AM processed specimens.

2020-03Journal article

Restricted access

Tribological performance of the pair human teeth vs 3D printed zirconia : an in vitro chewing simulation study

Publication . Branco, A. C.; Silva, R.; Jorge, H.; Santos, T.; Lorenz, K.; Polido, M.; Colaço, R.; Serro, A. P.; Figueiredo-Pina, C. G.

This study aims to evaluate the tribological performance of the pair human teeth/robocasted zirconia, with a special focus on the enamel wear mechanisms. Zirconia pieces produced by robocasting (RC) and unidirectional compression (UC) were compared in terms of crystalline structure, density, porosity, hardness and toughness. Chewing simulation tests were performed against human dental cusps. The cusps wear was quantified and the wear mechanisms identified. Although most of the properties of UC and RC samples are similar, differences were observed for surface roughness and porosity. Although the samples did not suffer wear, the antagonist cusps worn in a similar way. In conclusion, robocasting seems a promising technique to produce customized zirconia dental pieces, namely in what concerns the overall tribological behaviour.

2020-10Journal article

Restricted access

Effects of therapeutic and aerobic exercise programs on pain, neuromuscular activation, and bite force in patients with temporomandibular disorders

Publication . Moleirinho-Alves, Paula; Cebola, Pedro Miguel Teixeira Cravas; Santos, Paulo Duarte Guia dos; Correia, José Pedro; Godinho, Catarina; Oliveira, Raul Alexandre Nunes da Silva; Pezarat-Correia, Pedro Luís Cemacelha

Pain in masticatory muscles is one of the most frequent symptoms in patients with temporomandibular disorders (TMD) and can lead to changes in the patterns of neuromuscular activity of masticatory muscles and decrease in bite force. This study assesses the effects of three eight-week exercise programs on pain intensity, neuromuscular activation, and bite force of masticatory muscles in patients with TMD. Forty-five patients were divided into three groups: a therapeutic exercise program (G1), a therapeutic and aerobic exercise program (G2), and an aerobic exercise program (G3). The masticatory muscles’ pain was evaluated using the numeric pain rating scale (NPRS), surface electromyographic (sEMG) activity of the masseter was recorded during maximum voluntary contraction and at rest, and bite force was evaluated using a dynamometer. These parameters were evaluated twice at baseline (A01/A02), at the end of the eight-week intervention period (A1), and 8–12 weeks after the end of the intervention (A2). After intervention, G2 showed the best results, with a significantly decrease in masticatory muscles’ pain and increase in bite force. These results suggest that interventions to reduce pain in patients with TMD should be multimodal.

2021Journal article

Open access

A novel boot camp program to help guide personalized exercise in people with Parkinson disease

Publication . Domingos, Josefa; Dean, John; Cruickshank, Travis M.; Śmiłowska, Katarzyna; Fernandes, J. B.; Godinho, Catarina

Given the variety of exercise programs available for people with Parkinson’s disease (PD), such individuals may struggle to make decisions about what exercise to perform. The objective of this study was to assess the usefulness, satisfaction, and preferences regarding participation in a PD-personalized educational and exercise boot camp program. Attendees participated in a four-day program consisting of exercise sessions, workshops, and social activities. We collected demographic and clinical information. We assessed satisfaction and preferences immediately after. At one-month follow-up, participants assessed usefulness and changes in exercise habits. Eight individuals diagnosed with PD, with a mean age of 59.5 ± 6.8 years, participated. All participants felt “very satisfied” and likely to attend future events. The two favorite sessions were: cognitive stepping and dance-based movements. At one-month follow-up, participants considered the program “very useful” and reported changes in their exercise routine. Our results suggest that the boot camp program was considered useful and capable of influencing participants’ exercise habits.

2021Journal article

Open access

Use of digital educational technologies among nursing students and teachers: an exploratory study

Publication . Loureiro, Fernanda; Sousa, Luís; Antunes, Vanessa

The emergence of digital educational technologies (DET) raises questions regarding the personalization of both teaching and care. DET use implies profound changes with consequences in nursing care and in nursing teaching-learning process. With the purpose of contributing to the improvement of the teaching-learning process through the use of DET, an exploratory-descriptive, cross-sectional, and observational study, with a quantitative approach (descriptive and inferential statistics), was developed. Online questionnaires were applied (n = 140 students and n = 23 teachers) after ethics committee approval. Results point to low cost and access without time/space limits as the main benefits, and decreased interaction, less physical contact, and technical difficulties as constraints. Globally, there was no difference between students and teachers in the use of DET. Still, men report more constraints than women. In this sample, the use of DET is still at an early stage. Both students and teachers are still unfamiliar with the scope and possibilities of these tools, not taking full advantage of the potential they have to offer. The impact of DET used in personalized nursing care is still yet to be understood.

2021Journal article

Open access