3Institute for Medical Statistics and

Ozone is currently being discussed in dentistry as a possible alternative antiseptic agent. Its high antimicro-bial power without the development of drug resistance has been noted in water purification and food preserva-tion (1–3). Recent investigations have reported anti-microbial effects on oral pathogens of both gaseous and aqueous forms of ozone (4–11), and the effectiveness of ozone in the treatment of oral diseases is currently a subject of intensive research (12–15). In dentistry, ozone has been used either in gaseous (4.2 · 106 lg m)3; HealOzone, KaVo, Biberach, Germany) or in aqueous form for the elimination of caries pathogens, in the disinfection of root canals, as a rinse for avulsed teeth, and for enhancing epithelial wound healing (6,8,16–18). Currently, the establishe