Journal of Nepalese Prosthodontic Society

Abstract

Introduction:Polymethyl methacrylate as denture base material is not ideal in many aspects. Theprimary problem is its poor strength characteristics, including low impact and flexural strength. Thefatigue failure occurs when the denture base deforms repeatedly through occlusal forces, hence denturestend to break during usage in due course of time.The aim of this study was to measure and compare the flexural strength of heat cure Polymethylmethacrylate denture base resin with and without reinforcement of polyethylene fiber.

Method: A total of 52 specimens (maxillary complete denture) were divided into 2 groups(n=26);GroupA(Control): Dentures without reinforcement, Group B: Dentures reinforced with Polyethylene fiber.All specimens were subjected to three-point bending test in UTM. A flexural load was applied to eachmaxillary complete denture at a speed of 5mm/min until fracture and the flexural load required to breakspecimen was recorded.

Results: The mean values and standard deviation of each test specimen group was calculated andstatistical analysis of obtained values was done using ANOVA. Mean flexural strength for Group A was142.66±29.95 MPa and Group B was 218.88±29.96 MPa. Group comparison showed a statisticallysignificant difference (p<0.001) between group A and B. This suggested that flexural strength forspecimens reinforced with Polyethylene fibers was significantly higher than specimens withoutreinforcement.

Conclusion: Reinforcement of heat cure polymethyl methacylate denture base resin with polyethylenefiber resulted in significant increase in flexural strength.

Key words: Denture fractures, flexural strength, Heat polymerized acrylic resin, reinforcement, repairs.


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