Superficial and Inner Examination of a Microwave-Irradiated Dental Acrylic Resin and Its Metal–Polymer Interface

Abstract

The aim of this study is to conduct an extended surface and cross-section characterization of a denture base acrylic resin subjected to 500, 650, and 750 W microwave irradiation for 2, 3, and 5 min to assess its morphological modifications. A commercial heat-cured powder was polymerized according to the manufacturer's specifications and distributed into 20 circular samples. A stainless-steel wire was partially embedded in half of the discs, in order to investigate the metal-polymer interface. High-resolution scanning electron microscopy (SEM) imaging, white light interferometry, roughness measurements and Fourier transform infrared spectrometry were employed for morphological and structural evaluation of the irradiated polymer. Superficial adaptation was discovered after 5 min exposure at 500 W, 650 W, and 750 W, revealing significant roughness correction for 750 W. SEM characterization revealed the inner alteration of the resin for the 750 W protocol and a metal-polymer gap developed regardless of the irradiation conditions. The considerable temperature fluctuations that the samples were subject to during the experiments did not essentially change the poly(methyl-methacrylate) bond structure.

Enhanced XRF Methods for Investigating the Erosion-Resistant Functional Coatings

“…The SEM measurements were carried out by means of an Apreo instrument (Thermo Scientific, Waltham, MA, USA), which produces enlarged images of a variety of specimens, achieving magnification of over 100 000 × (ideal conditions), providing high resolution imaging in a digital format. The SEM images were acquired at a working pressure of 1.5 x10 −2 Pa, a working distance between 8-22 mm, and an electron acceleration voltage of 10-25 kV [35][36][37].…”