Evaluation of Flexural Strength of Autopolymerizing Polymethyl Methacrylate and Bis-acrylic Composite Provisional Restorative Resins Reinforced with Bamboo Fibers: An In Vitro Study

Abstract

Aim and objective: The aim is to reinforce autopolymerizing polymethyl methacrylate (PMMA) and bis-acrylic composite (BAC) provisional restorative resin with bamboo fibers and evaluate its effect on the flexural strength of the resin in comparison to the unreinforced material. The objective of the study is to find a suitable natural alternative to synthetic fibers like glass to strengthen the materials used for fabricating provisional fixed partial dentures. Materials and methods: A total of 4 groups each containing 15 samples of 25 × 2 × 2 mm dimension namely group I: unreinforced PMMA, group II: PMMA resin reinforced with bamboo fibers, group III: unreinforced BAC and group IV: BAC resin reinforced with bamboo fibers. The bamboo fibers of 22 mm length were initially pretreated with 6% Sodium hydroxide solution for 12 hours and dried thoroughly for 2 weeks. The dried fibers were placed longitudinally in the reinforced samples by a layering method at 5% w/w concentration. For determining the flexural strength, specimens were then tested by 3-point bend test on universal testing machine. The fractured samples were then analyzed using scanning electron microscope at 50×, 100×, 250× magnification. Results: The results obtained were analyzed in STATA software release 14.0 using one-way ANOVA test. According to the results, the mean flexural strength (in MPa) values were group IV (152.42) < group II (127.2) < group I (99.28) and was statistically significant p = 0.001. Conclusion: Thus, bamboo fibers have a reinforcing effect on autopolymerizing polymethyl methacrylate and bis-acrylic composite provisional restorative resins and significantly increases their flexural strength.