Investigating the Potential of Walnut Shell Powder as a Filler in PMMA Denture Bases

Abstract

With an increasing of dental problems for aging population, there is more needing for more effective treatments to enhance the quality of denture base. Natural powders have biocompatibility characteristics and considerable mechanical properties as well as being inexpensive and eco-friendly. Poly methyl methacrylate (PMMA) is widely utilized in medical and dental field due to its high compatibility and ease of manufacturing. However, its mechanical properties are relatively weak. In current work, PMMA bio composites were reinforced with walnut shells powder of two particle sizes (25 and 150 μm) in various concentrations. Physical and mechanical properties of bio composites were investigated. SEM showed a dense and smooth bio composite morphology, indicating strong PMMA-reinforcement adhesion with no new phases. The results exhibited a considerable advancement in the mechanical properties values for all bio composite specimens as compared with neat PMMA. Specimens that strengthened with fine size from walnut shells powder exhibited enhanced properties compared with those of the coarse size for the same material. For composites reinforced with fine particles (25μm), the maximum values for compression strength and hardness for samples strengthened with were 325.56 MPa and 86 shore-D respectively. In contrast, composites reinforced with coarse particle (150μm) of the same material had the maximum values of 306.409 MPa and 82.2 shore-D respectively. In light of the findings, it can be concluded that adding of fine particles of walnut shells powder to neat (PMMA) resin is one of the promising substances utilized to enhance the mechanical properties for denture bases more than coarse particles.