Evaluation of the Effect of Addition of Silver Nanoparticles on the Thermal Conductivity and Impact Strength of Heat-Cured Polymethylmethacrylate – An In Vitro Study

Abstract

Introduction

Heat-cured Polymethyl methacrylate (PMMA) is a widely used material in prosthodontics due to its excellent aesthetics, biocompatibility, and ease of manipulation. However, its inherent limitations, such as low impact strength and poor thermal conductivity, have driven research into modifying its properties. The addition of silver nanoparticles (AgNPs) has shown potential in enhancing these properties.

Materials and methodology

This study aimed to evaluate the effect of incorporating 10% silver nanoparticles into heat-cured PMMA. A total of 80 specimens were prepared, of which 40 were used for testing thermal conductivity and rest for testing impact strength, where subgroups were further divided into control and test groups that consisted of 20 specimens each. Group A (control) consisting of conventional PMMA, and Group B (experimental) comprising PMMA reinforced with 10% silver nanoparticles. Thermal conductivity was measured using the KD2 Pro Thermal Analyzer, while impact strength was tested with Charpy’s Impact Tester. Data were analyzed using the Mann–Whitney U test. PMMA was chosen for its common use in prosthodontics, and 10% silver nanoparticles for their potential to enhance properties. Standardized specimen preparation ensured reliability, with thermal conductivity measured using the KD2 Pro Thermal Analyzer and impact strength assessed via Charpy’s Impact Tester. The Mann–Whitney U test provided robust statistical analysis.

Results

The experimental group exhibited a significant improvement in both thermal conductivity and impact strength. Group B showed a mean thermal conductivity of 0.188 ± 0.005 W/m·K, significantly higher than the control group (0.169 ± 0.005 W/m·K, p=0.001). The mean impact strength was also greater in Group B (19.76 ± 0.75 J/m) compared to the control group (7.16 ± 0.34 J/m, p=0.001).

Conclusion

Reinforcing PMMA with 10% silver nanoparticles significantly enhances its thermal and mechanical properties, making it a promising material modification for clinical applications in prosthodontics.