Evaluation of the impact of nano and micro-hydroxyapatite particles on the transverse strength and hardness of PMMA material

Abstract

Poly (methyl methacrylate) is considered as the basis material for a denture base. However, such substance has some drawbacks such as poor impact resistance, which is thought to be the primary cause of fracture of denture base resins. The purpose of the study was to determine how Nano and Micro hydroxyapatite particles affected the transverse strength and surface hardness of Poly methyl methacrylate. sixty samples were prepared in total and divided into 2 main sets according to the test used (surface hardness and transverse). For each test, there were 3 groups (control, 1% HA nanofiller and 5% HA microfiller) and each group had 10 samples. All samples were subjected to transverse strength and Hardness test. Data were then analyzed using SPSS v20. The ANOVA test used for comparison among the groups. The addition of Nano and Micro hydroxyapatite to polymethyl methacrylate (PMMA) decreased the transverse strength of the heat-polymerized acrylic resins. Furthermore, the incorporation of Nano and Micro hydroxyapatite improved the surface hardness of the heat-polymerized acrylic resins. Incorporating Nano and Micro hydroxyapatite to PMMA improved the sur-face hardness and decreased the transverse strength of acrylic resins.