Examinando por Materia "Surface microhardness"

Mostrando 1 - 3 de 3

Acceso abierto
Comparative in vitro study of the surface microhardness of low viscosity fluid composite resins for the use of dental sealants, Lima 2022
(Universidad Privada Norbert Wiener, 2023-10-18) Córdova Luque, Edy Jimmy; Guillén Galarza, Carlos Enrique
The aim of this research is to evaluate the surface microhardness of low-viscosity flowable composite resins, 3M Filtek Flow™, Tetric N-Flow, and Opallis Flow for use as dental sealants. A comparative, in vitro, descriptive, prospective, and cross-sectional study was conducted, consisting of 60 low-viscosity flowable resin cylinders, divided into 20 cylinders for each group. The samples were measured after 24 hours. Microhardness was evaluated using a Vickers microhardness tester, applying a 50-gram indentation on each sample in each resin cylinder. Data were collected on a data collection form and analyzed with SPSS statistical software, version 22.0. The results of surface microhardness showed that the Opallis Flow resin had a value of 52.23 Kg/mm², followed by Tetric N-Flow with a value of 40.72 Kg/mm², and 3M Filtek Flow™ with 40.17 Kg/mm². In conclusion, the Opallis Flow resin has the highest surface microhardness compared to Tetric N-Flow and 3M Filtek Flow™
Acceso abierto
Effect of the type of sugar-free industrialized beverage and the exposure time, on the magnitude of the superficial micro-hardness of the enamel of permanent dental pieces.
(Universidad Privada Norbert Wiener, 2021-10-23) Iberico Castro, Maria Fernanda; Araujo Farje, Jessica Jazmin
An experimental design was developed to evaluate the surface microhardness of 40 enamel blocks after being exposed to four sugar-free beverages. These specimens were divided into 5 groups: Coca-Cola Zero, Free Tea, Red Bull Sugar-Free, Electrolyte, and the control group using 0.9% Sodium Chloride. The enamel blocks were immersed in the corresponding beverages for 10 minutes once a day, for a period of 5 days. On the first, third, and fifth days, the surface microhardness of each enamel block was measured. Results: This study found that all the beverages tested had a significant effect on the surface microhardness of the enamel blocks exposed to them.
Acceso abierto
Mechanical surface microhardness of a thermo-curing acrylic resin associated with zirconium nanoparticles
(Universidad Privada Norbert Wiener, 2023-10-23) Apomayta Hinojosa, Michael; Vilchez Bellido, Dina
Objective: To determine the mechanical surface microhardness of a thermocured acrylic resin associated with zirconium nanoparticles, Lima - Peru. Materials and Methods: This research is an in-vitro experimental study, cross-sectional, and prospective. The sample consisted of 03 study groups, which were further divided into 06 subgroups, measured at 24 and 48 hours, and met the inclusion and exclusion criteria. The equipment used for the measurement of mechanical surface microhardness was the Vickers microhardness tester, and the data was recorded on a data collection form. Statistical analysis was conducted using the Shapiro-Wilk test, and for bivariate analysis of the mechanical surface microhardness values between the materials, the ANOVA-Tukey test (24 hours) and Kruskal-Wallis with post hoc Dwass-Steel-Critchlow-Fligner pairwise comparisons (48 hours) were used. Comparisons between the 24-hour and 48-hour results were made using the Mann-Whitney U test and Student's T-test. All tests were analyzed with a 95% confidence level. Results: The acrylic resin associated with 3% zirconium nanoparticles showed the highest bond strength value (p < 0.05), followed by the acrylic resin.