Mechanical Properties and Formulation of Hydrophilic Fiber and Shrimp Shell Combination as a Novel Eco-Friendly Dental Restoration Material

Dewi Nur Fadhila. *Mechanical Properties and Formulation of Hydrophilic Fiber and Shrimp Shell Combination as a Novel Eco-Friendly Dental Restoration Material.* (Supervised by Nursyamsi, drg., M.Kes). This study evaluates the mechanical properties and formulation of dental restoration material comprised of cellulose acetate (CA) from water hyacinth and chitosan (C) from white shrimp shells. The research phases included extraction, formulation, functional group testing, antibacterial, toxicity, water absorption and solubility, compressive, shear, tensile, hardness, microleakage, thermal expansion, and shrinkage. The experimental data were analyzed using probit regression, one-way ANOVA, and Kruskal-Wallis test. The data showed CA and C had microxyl and amine groups, could inhibit *S. mutans,* and were non-toxic. Composite resins were divided into nine formulations with different concentrations: F1 (1% CA + 3% C), F2 (1% CA + 5% C), F3 (1% CA + 7% C), F4 (3% CA + 3% C), F5 (3% CA + 5% C), F6 (3% CA + 7% C), F7 (5% CA + 3% C), F8 (5% CA + 5% C), and F9 (5% CA + 7% C).

The F9 formulation showed mechanical strength close to the control group, including 113.33 µg/mm³ absorption, 80 µg/mm³ solubility, 32.67 MPa compressive strength, 17.18 MPa tensile strength, and no shrinkage. This indicates that F9 has potential as an eco-friendly dental filling material. The study completed the development of a formulation for a restoration material by combining water hyacinth fiber and shrimp skin chitosan. The outcomes of a comparative analysis of the mechanical properties of synthetic composite resins and water hyacinth fiber composites containing shrimp skin chitosan revealed that the F9 formulation (CA 5% + C 7%) exhibited the following fiber properties: absorption, compressive strength, tensile strength, hardness, and thermal expansion.