PMMA – EGGSHELL COMPOSITE PREPARATION AND STUDYING MECHANICAL PROPERTIES AS A DENTAL MATERIAL

Abstract

In recent years, many researchers used polymethyl methacrylate in dental applications due to good mechanical and physical properties. In this research, the eggshell powder had mixed with polymethyl methacrylate resin for the preparations of new composite materials have good mechanical properties and low cost compared with industrially processed powders. The hand lay-up technique was adopted for the preparation specimens composite materials that made from a polymethyl methacrylate as a matrix with (1%, 3%, 5% and 7%) weight fraction eggshell powder (before and after burning) a reinforcement material. The mechanical properties were analyzed by utilizing (SPSS) according to (One-Way ANOVA). The results showed that the addition of the eggshell (before and after burning) powder at a ratio of (7% weight fraction) improves the values of tensile properties and fracture toughness, while this ratio leads to a decrease in values of elongation percentage at break and impact strength compared with other specimens. Also, the results showed that the Sig value was lower in all mechanical properties of specimens reinforced with eggshell powder after burning than specimens reinforced with eggshell powder before burning with a polymethyl methacrylate resin, where the percentage of improvement was in ultimate tensile strength 64 %, modulus of elasticity 13 %, elongation percentage 6 %, impact strength 75% and 81% fracture toughness.