Dental Unit Waterlines have come under increasing scrutiny as residents of biofilms which harbor and release bacteria and in some instances harmful pathogens. As a result ADA has pro actively recommended that the water delivered by dental equipment have <200 colony forming units (CFU) of heterotrophic, mesophilic bacteria/ml of water. ? ? To date we have significantly exceeded our Phase 1 objectives. We demonstrated that within 5 minutes, moderate levels of dissolved O3 (>3 mg per liter) can remove all of the planktonic bacteria and reduce biofilm levels by 99.99%. This suggerts that routine treatment (e.g. 1 hour/day) with O3 will treat both free floating planktonic bacteria and biofilms. We have also shown through the use of a confocal laser scanning microscope that >50% of the microbial load in the biofilm can be inactivated within three minutes of treatment. ? ? We also demonstrated the supply of dissolved O3 in water without bubbles using composite CMS perfluoromembranes on chemically resistant micro porous supports. In parallel we have also established a commercial supply of CMS membrane devices for bubbleless O3 delivery and have demonstrated the performance of a commercial chemically inert CMS membrane device for ozone dissolution. Since we have the key components in place, commercialization of the O3 delivery system is simplified. Phase II will focus on expanding this technology towards the delivery of a functional prototype for clinical testing at a dental practice. We have brought on board 2 biofilm experts to evaluate biofilm removal and study potential for regrowth. Customization of the membrane device will be conducted during the Phase II study, prior to market introduction during Phase III. ? ?