Effect of Incorporation of Silane-Treated Silver and Aluminum Microparticles on Strength and Thermal Conductivity of PMMA

Purpose: The purpose of this study was to study the effect of addition of metal filler particles on different strengths of polymethylmethacrylate (PMMA) and to evaluate the thermal perception in vivo. Materials and Methods: The study was carried out in two parts. Part 1 of the study was an in vitro investigation regarding the effect of addition of metal fillers (aluminum and silver) in concentrations of 10%, 20%, and 30%, by volume on the tensile, compressive, and flexural strength of PMMA. Part 2 of the study comprised the clinical evaluation of the thermal perception by 10 edentulous patients provided with two sets of complete dentures, one fabricated with unfilled PMMA and another with 20% aluminum particle filled PMMA on the palatal portion of the maxillary denture. Recorded data were subjected to Student's t-test and ANOVA test. Results: The mean tensile and flexural strength values among control and other groups were found to have statistically significant differences (p < 0.05) except for Al1 and Al2 groups. Mean compressive strength values among control and other groups were statistically significant (p < 0.05). In the clinical study, all 10 participants reported higher perception of hot and cold sensations in dentures with a metalized palatal portion. Conclusions: Compressive strength increased progressively on increasing the filler concentration for both silver- and aluminum-filled PMMA. Silane-treated metalized PMMA showed reduction in tensile and flexural strength at 30% concentration. Metalized dentures led to an appreciable increase in thermal perception by the participants of this study.