Effect of surface treatment hybridization of kenaf nanocellulose on the thermal stability and mechanical properties of rice husk nanohybrid dental composite

The use of fillers based on natural resources in composite materials represents a massive potential for biomedical applications. However, up to this date, the use of natural resources for materials reinforcement in dental field is still lacking. Thus, the suitability of using kenaf cellulose nanocrystals as a co-filler treated via silane hybridization was assessed by means of thermal stability and mechanical strength of rice husk nanohybrid dental composite. Kenaf cellulose nanocrystals (CNCs) were surface-modified and treated with silane hybridization at varying ratios of γ-methacryloxypropyltrimethoxysilane and tetraethyl orthosilicate sol–gel (0:1, 1:1, 1:2, and 1:3). Following chemical and thermal analysis, the treated kenaf CNCs were incorporated into the nanohybrid rice husk dental composites (K00, K01, K11, K12, and K13). The prepared samples were sent for flexural and compressive strength tests. The Fourier transform infrared spectroscopy spectra detected the formation of chemical bonds between kenaf CNCs and γ-MPS/TEOS hybridized silane. For thermogravimetric analysis, the untreated kenaf CNCs recorded the highest decomposition temperature compared to silane-treated kenaf CNCs. The K13 composite (silane-treated kenaf CNCs with γ-MPS:TEOS of 1:3) demonstrated an enhanced flexural strength of 31% and compressive strength of 38% compared to the non-fiber-reinforced composite. In conclusion, optimal surface treatment hybridization of kenaf CNCs with silane at γ-MPS:TEOS of 1:3 significantly enhanced the mechanical properties of the rice husk nanohybrid dental composite and insignificantly influenced the thermal stability of the composite.