Assessment of surface hardness and impact strength of denture base resins reinforced with silver–titanium dioxide and silver–zirconium dioxide nanoparticles: In vitro study

Abstract

Abstract Polymethyl methacrylate (PMMA) is frequently utilised for fabricating denture bases due to its perfect qualities. However, a significant issue with this resin is the occurrence of frequent fractures caused by heavy chewing power, resulting in early cracks and fractures during clinical use. This study investigates the influence of silver, titanium dioxide, and silver zirconia nanoparticles on the surface hardness and impact strength of self-cured denture base. The samples were categorised into four categories according to the incorporation of different nanoparticles. The samples were divided into three subgroups based on the nanoparticle content: 0.1, 0.3, and 0.5% of TiO2 and ZrO2. Each group had a set ratio of 0.3% Ag as an antibacterial agent. Except for the fourth group (Group D), a combination of 0.05, 0.15, and 0.25% of TiO2 and ZrO2, along with 0.3% Ag, was utilised to investigate their collective impact. The Shore D hardness and Charpy test were employed to quantify the surface hardness and impact strength, respectively. The samples were subjected to X-ray diffraction analysis and field emission-scanning electron microscopy to characterise nanoparticles and ascertain the structure of acrylic samples. All nanoparticle-modified samples showed a substantial improvement in surface hardness compared to the control group. The maximum hardness value was seen in the samples containing 0.3% Ag–0.3% TiO2 and 0.3% Ag–0.5% ZrO2. The samples treated with 0.3% Ag and 0.3% TiO2 showed the maximum impact strength. The incorporation of Ag and ZrO2 hinders the ability to withstand impact strength. The samples treated with 0.3% Ag, 0.15% TiO2, and 0.15% ZrO2 exhibited an augmentation in impact strength. Modified samples in all groups showed a colour change, which required colour modifiers.