1. Department of Restorative Dentistry, University of the Western Cape, Bellville 7535, South Africa
2. Department of Science and Innovation (DSI)/Mintek Nanotechnology Innovation Centre (NIC) Biolabels Research Node, Department of Biotechnology, University of the Western Cape, Bellville 7535, South Africa
3. Oral and Dental Research Laboratory, University of the Western Cape, Bellville 7535, South Africa