Effect of Bombyx Mori Silk Fiber Volumetric on Water Sorption of Fiber-reinforced Composite

Background: Dental resin is frequently reinforced with synthetic dental fibers like glass fiber. Dental glass fiber can be challenging to find and costly in Indonesia. Bombyx mori silk fiber is a robust, convenient, and reasonably priced natural fiber substitute. Bombyx mori silk fiber is commonly used in medicinal applications as a post-surgical suture. Aim: The aim of this study was to assess the volumetric effect of Bombyx mori silk fiber on the water sorption of fiber-reinforced composite (FRC). Material and Methods: This study was an experimental laboratory. The materials used in this study were Bombyx mori silk fiber and flowable composite. Four groups of FRC samples were made using volumetric fibers at 0%, 5%, 10%, and 15% (n = 4). The test of water sorption was standardized (ISO 4049). The results were analyzed using one-way ANOVA (p<0.05). Results: The mean of water sorption of Bombyx mori silk fiber FRC for volumetric 0%, 5%, 10%, and 15% were: 0.475±0.030%; 0.681±0.033%; 0.889±0.008%; 1.318±0.039%, respectively. The present study showed that Bombyx mori silk fiber volumetric influenced the water sorption of FRC (p<0.05). Conclusion: The increased Bombyx mori silk fiber volumetric significantly increased the water sorption of FRC. The presence of a small gap caused by the weak interfacial bonds of the dental resin and fiber leads to water penetration.