Based on an extensive research collaboration between Linköping University and Bengt Danielsson at Lund University, and now at Acromed Invest AB. Nano-sensors based on zinc oxide crystals in the form of nano-rods have turned out to be an interesting commercial field for Acromed Invest AB. They are suitable for mass fabrication and multi-sensing and we intend to use them as sensors for studies of the chemistry in the oral cavity and dental health such as the SensOral project. All normal and abnormal conditions in the oral cavity are reflected in the composition of biofilms on surfaces and mucosa. Also the level of chemical components in the blood stream, e.g. glucose, will be in equilibrium with the concentration found in the oral cavity.