Investigation of Impact Strength, Water Sorption and Cytotoxicity of Denture Base Resin Reinforced with Polypropylene Fiber: In Vitro Study

Abstract

Aim: Polymethyl methacrylate is the common material used as a denture base. Ease of application, stability in the oral environment are its advantages; however, its mechanical properties should be enhanced. This study aimed to evaluate the effect of different ratios of polypropylene fiber (PPF) in addition to denture base materials on impact strength, water sorption, and cytotoxicity. Materials and Methods: Heat-cure acrylic resin specimens were prepared according to the manufacturer’s instruction by adding PPFs of 6 mm length in different ratios (1, 3, 5, 10, and 20 wt%). In order to determine the impact strength, specimens were subjected to a Charpy impact test machine after being kept in distilled water at 37°C for 48 h. A span of 40 mm was adjusted and a 0.5 J pendulum was used. The fractured surface of specimens was also analyzed using a scanning electron microscope. In addition, mouse fibroblast cells and agar diffusion tests were used for cytotoxicity determination. The results were analyzed using the Kruskal–Wallis and the Mann–Whitney U tests for determining impact strength, and Kruskal–Wallis and Tukey’s range tests were performed for determining water sorption values ( P = 0.05). Results: 5 wt% PPF group exhibited the highest water sorption and impact strength values, and the difference was statistically significant ( P < .05). On the other hand, no cytotoxic effects were determined in PPF added groups. Furthermore, increased fiber concentration caused less water sorption. Conclusion: Addition of PPFs in acrylic resin increased the impact strength and decreased water sorption without any cytotoxic effects.