resumo
In this study, we have demonstrated, for the first time, the use of diamond film thermistors for dental vitality assessment. Thermally sensitive boron-doped diamond films were grown by hot-filament CVD on Si3N4 ceramic substrates, and their thermal sensitivity (beta) in the 30-50 degrees C range was optimized using the Taguchi methodology. This analysis facilitated a comprehensive investigation into the effects of argon flow, gas pressure, CH4/H2 ratio, and the distance between the sample and heated filaments on the films' microstructure, growth-rate (GR), crystalline quality, and beta. Additionally, we introduced an empirical parameter (Y), defined as the ratio of beta to electrical resistance. Using optimized CVD parameters, we fabricated a fully functional diamond thermistor with a thermal sensitivity of 1435 K, which was then used in dental vitality assessment tests. These tests were conducted on a specialized stand featuring two closed water circuits, allowing the tooth to be cooled to temperatures as low as 10 degrees C and heated up to 40 degrees C. The heating response times of our diamond thermistor (DT) and a standard, metaloxide-based commercial thermistor (CT) were comparable, but the diamond sensor exhibited a broader temperature detection range. Specifically, the DT was able to detect tooth temperatures within the range of 18 degrees C to 35 degrees C, whereas the CT was limited to a narrower range of 22 degrees C to 32 degrees C. Additionally, the cooling response time for the DT was significantly shorter (190 s) compared to the 260 s required for the CT. These findings highlight the potential of planar diamond thermistors for applications in endodontic medicine, enabling more accurate assessments of dental vitality.
palavras-chave
GROWTH; TEMPERATURE; OXYGEN; ADHESION; ARGON; GAS
categoria
Materials Science; Physics
autores
Neto, MA; Caramelo, F; Tavares, BL; Fernandes, AJS; Girao, AV; Silva, RF; Oliveira, FJ
nossos autores
Ana Violeta Girão
Investigador Júnior
Bernardo Loureiro Tavares
Estudante de doutoramento
Filipe José Alves de Oliveira
Investigador Principal
Miguel Ângelo da Costa Neto
Investigador Principal
Rui Ramos Ferreira e Silva
Professor associadoGrupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES.