Patent ID: 6991736

Claim:
A method of continuously treating dental unit water, comprising: passing the source water through a water-permeable element having received therein a metal ion sustained release source that releases into the source water at least one microbiocidal metal ion selected from the group consisting of silver, zinc, gold and copper ions to initiate residual disinfection properties into the source water, thereby changing the source water to a treated dental unit water; wherein the metal ion release source comprises a colorant, flavorant and/or odorant that is released into the treated dental water to provide an indication as to when the metal ions are initially present in the treated dental water, and supplying the treated dental unit water to at least one dental instrument via at least one dental unit waterline whereby the residual disinfection properties of the treated dental unit water are sufficient to kill existing biofilm established in the dental unit and reduce additional biofilm growth.