Disclosed is a new method, and a system, for increasing the pH of a composition applied on teeth and/or gums. The composition is gelable under the influence of a pH change. The pH change typically is a pH increase in the event of a direct pH-triggered gelation. The pH change typically is a pH decrease in the event of gelation induced by ions, such as calcium ions, released from a pH-sensitive carrier. The device comprises a dispensing unit for the composition, a distal end of which is adapted to apply said substance onto teeth or gums. The device further comprises an electrode system comprising first and second electrodes, the first electrode being adapted to be held against the composition at a location at or near teeth or gums, and the second electrode being adapted to be held against the composition at a location away from teeth or gums, The electrode system is adapted so as to provide an electrical potential difference of 1.5 to 10 Volt between the electrodes.
