The present invention is in the field of tooth cleaning devices, especially electrical toothbrushes. The invention further relates to the use of an air/water jet for the cleaning of teeth. A process for cleaning teeth that incorporates a water jet for cleaning teeth remains to be desired, especially a single device that can be employed to clean teeth and reliably deposit material onto teeth. It is therefore an object of the present invention to provide a process for cleaning teeth with an electrical toothbrush device providing improved cleaning by means of an externally mixed air-water jet wherein the water dosing is not influenced by the air pressure. Surprisingly it has been found that a tooth brush device, comprising an air/water jet, wherein the air and water are mixed outside the nozzle(s), provides improved cleaning of dental surfaces, including inter-proximal areas, with low usage of water.