Synthesising silica for use in dental nano-composites through the sol–gel process is considered a time-consuming and often dangerous method owing to the toxicity of the materials involved. Researchers from the School of Dental Sciences of Universiti Sains Malaysia claim to have developed a more cost-effective and environmentally friendly method to extract the vital substance from rice husks, the outer shell of rice grains.

In Malaysia alone, an estimated 0.5 million tons of this crop residue from the milling of rice are discarded annually. The global annual production is estimated to exceed 100 million tons, resulting in a vast amount of organic waste in South-East Asia particularly, where it is used as fertiliser, insulation material and fuel to power steam engines, among other applications.

With a silica content of 10 per cent, it could be a low-cost source for the production of silica nanoparticles, which are the main component of composite fillings used in dentistry, according to project leader Prof. Ismail Ab. Rahman from the school. He said that production costs could be reduced by almost two-thirds using his method compared with conventional synthesis of silica from organic silicon compounds.

The first dental composite produced from silica components acquired from rice husks was presented by Rahman and his research team at the 24th International Invention, Innovation and Technology Exhibition in Kuala Lumpur last week, where it was awarded a silver medal, among 1,000 innovations presented by researchers from around the world. Rahman said that the material could be ready for market launch by as soon as 2016 and after it has undergone thorough testing on animals and humans.

According to him, the material can last in the mouth for up to ten years, a life expectancy comparable to commonly used metal fillings, such as amalgam, and other composite resins.

Original Source: The Dental