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Copyright © 2018 Rafaella de S. Leão et al. This is an open access article distributed under the Creative Commons Attribution License (the “License”), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. http://creativecommons.org/licenses/by/4.0/

Abstract

Herein, the effect of different post-pressing times and pressure in two cycles of polymerization on the degree of conversion (DC) of thermally activated acrylic resin (TRRA) is analyzed to optimize the polymerization of this material. After post-pressing for 0, 6, or 12 h, polymerization was performed with or without a pressure of 60 psi (0.41 MPa) in a short (4 h) or a long (11 h) cycle, totaling 12 groups. To determine the DC, PMMA specimens were analyzed by Fourier transform infrared spectroscopy. The influence of each factor alone on the DC was studied by experimental planning. The statistical tests used were three-way ANOVA, t-test, Tukey’s test, and Levene’s test, with a margin of error of 5%. Two groups prepared with post-pressing times of 12 h had the lowest DC (p<0.001). Post-pressing times of 0 and 6 h did not yield statistically different results. Pressure increased the DC in only one group (long cycle +12 h, p=0.001). The short cycle resulted in a higher DC than the long cycle in 2 groups (with pressure +0 h, p=0.002; without pressure +6 h, p=0.015), while the long cycle yielded a statistically higher DC in only one group (with pressure +12 h, p<0.001). The polymerization showed satisfactory DC in all 12 groups. Small differences found among the specimens indicate that the pressure, post-pressing time, and polymerization cycles herein were not influential factors for the DC of PMMA.

Details

Title
Effect of Pressure, Post-Pressing Time, and Polymerization Cycle on the Degree of Conversion of Thermoactivated Acrylic Resin
Author
Rafaella de S Leão 1   VIAFID ORCID Logo  ; Sandra L D de Moraes 2 ; Kátia A da S Aquino 3   VIAFID ORCID Logo  ; Isolan, Cristina P 4 ; Bruno G da S Casado 1   VIAFID ORCID Logo  ; Marcos A J R Montes 1 

 Department of Restorative Dentistry, Faculty of Dentistry, University of Pernambuco-FOP/UPE, Av. Gal. Newton Cavalcanti 1650, 54753-020 Camaragibe, PE, Brazil 
 Department of Prosthodontics, Faculty of Dentistry, University of Pernambuco-FOP/UPE, Av. Gal. Newton Cavalcanti 1650, 54753-020 Camaragibe, PE, Brazil 
 Department of Nuclear Engineering, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235-Cidade Universitária, 50670-901 Recife, PE, Brazil 
 Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Pelotas (UFPel), R. Gonçalves Chaves, 457-Centro, 96015-560 Pelotas, RS, Brazil 
Editor
Gianrico Spagnuolo
Publication year
2018
Publication date
2018
Publisher
John Wiley & Sons, Inc.
ISSN
16878728
e-ISSN
16878736
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2093137368
Copyright
Copyright © 2018 Rafaella de S. Leão et al. This is an open access article distributed under the Creative Commons Attribution License (the “License”), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. http://creativecommons.org/licenses/by/4.0/