A comparative study of heat-cured and gamma-cured fiber-reinforced denture-base acrylic resins: Residual monomer and flexural strength

Abstract

This study was performed to determine and compare the effect of heat and gamma-ray polymerization methods on the residual monomer and flexural strength of polyethylene fiber-reinforced denture-base acrylic resins. Four groups ( n = 10) of specimens of polyethylene fiber-reinforced denture-base material were prepared in the form of thin disks. The first group was subjected to heat-curing and the other three groups were polymerized with gamma irradiation at doses of 15, 25, and 35 kGy, respectively. Fourier-transform infrared (FTIR) spectrometer was used to monitor the corresponding polymerization processes. The analysis of residual monomer was carried out by high-performance liquid chromatography–photodiode array detector. A three-point bending test was used to evaluate the flexural strength of the samples. The one-way analysis of variance test was performed to determine the significant differences between the groups. The absence of the bands related to carbon–carbon double bond in the FTIR spectra of all test groups was an evidence of polymerization. The mean weight percentage of residual monomer was successively ranked from highest to lowest in; heat-cured, gamma-cured at 15–35 kGy. However, no significant difference ( p = 0.462) was found between gamma-cured samples at 25 and 35 kGy. Mechanical test results revealed that heat-cured samples had higher flexural strength than gamma-cured specimens ( p < 0.001). Within the limitations of this study, polymerization with gamma-rays at 15 kGy was proposed as a promising technique in terms of the residual monomer and flexural strength results.

Protocols of improvements for PMMA denture base resin: An overview

“…They studied the effect of the irradiation dose on the thermal characteristics of the resin, and a high molecular weight cross-linked polymer with low porosity is produced using this technique. Furthermore, others [66] inferred that gamma cured PMMA exhibited minimal levels of remaining monomer because of higher penetration depth of the irradiation, denoting gamma curing processes is a very efficient method for reducing the unpolymerized MMA in denture base polymers. In addition, gamma irradiation improved the biocompatibility parameters of the polymer due to the combination of oxygen and the produced free radicals [70].…”

Effects of graphene on thermal properties and thermal stability of polycarbonate/graphene nanocomposite

“…Out of the different inorganic nanofillers, carbon-based nanofillers such as carbon black, graphite, fullerene, carbon nanofiber, and carbon nanotube are commonly used fillers due to their high thermal and electrical conductivity. [5][6][7][8][9][10][11][12][13][14] After discovering single layer graphene in the year 2004 by Andre Geim and Kostya Novoselov of the University of Manchester, graphene is taken as a new member in the group of carbon-based nanofillers. Graphene is a two-dimensional crystalline allotrope of carbon in which carbon atoms are sp 2 hybridized and are densely packed in a honeycomb crystal lattice.…”