SOLUMIUM DENTAL: the hyper-pure chlorine dioxide solution and its applications in dentistry I

This series of papers consisting of three communications describes the properties and applications of chlorine dioxide (ClO2) with a special emphasis on its hyper-pure aqueous solution available commercially in Hungary under the trade name SOLUMIUM DENTAL since the end of 2008. This first part of the series discusses the history of chlorine dioxide as a disinfectant, its properties and its fields of applications. It is also explained why chlorine dioxide is regarded as an ideal biocide and why its medical applications were delayed until now in spite of its advantageous properties as a biocide. The history of chlorine dioxide ClO2 and its fields of application Chlorine dioxide is a greenish yellow gas, easily soluble in water and aqueous solutions. It had been known for long. It was discovered by Sir Humphry Davy in 1811, however it became well known in the XX century only. The largest quantities are used in the paper industry for whitening cellulose. In this application it replaced chlorine because the latter produces dioxin which is carcinogenic. Its second most important field of application is the disinfection of municipal water. For this purpose it was first used in the small town of Niagara Falls next to the Niagara Water Falls in 1944 substituting chlorine. Chlorine dioxide has many favourable properties compared to chlorine. Its disinfectant effect exceeds that of chlorine, moreover it does not chlorinate organic compounds. In Niagara Falls the water was contaminated with phenol, which caused the problems, because chlorine transformed phenol into chlorophenol, which gave the water a really bad taste. What is more, during the chlorination of water so-called trihalo methanes (THM) are formed, which are carcinogenic. It is therefore advisable to change over from the cheaper chlorine to the more expensive but healthier chlorine dioxide where the water contains a higher amount of organic materials. This had been done first in 1956 in Bruxelles among the big cities. Application of ClO2 in the food industry, oral hygiene and dentistry Recently chlorine dioxide solutions were introduced for other purposes, like in the United States for washing fruits and meats. Besides disinfection chlorine dioxide can be used also for deodorizing, for mouthwash, and for other purposes. Chlorine dioxide not only kills all the bacteria responsible for bad breath but directly reacts with the sulphur containing compounds (like sulphurhydrogen, methyl-mercaptan and dimethyl-sulphide) causing the bad breath, and this way successfully stops halitosis as demonstrated by a very thorough Japanese study [1]. The same paper emphasizes two important advantages of mouthwashes made with chlorine dioxide compared to those containing chlorohexidine: the former does not discolour the teeth and tongue and even its continuous use does not produce unwanted side effects. The wide spread of these mouthwashes has been hindered as besides chlorine dioxide they also contained other chemicals which unfavourably affect on one side the quality and on the other side the long term stability of these mouthwashes. To avoid problems caused by the instability chlorine dioxide can be prepared on the spot by mixing the necessary chemicals. This procedure is used e.g. by the DioxiCare [2] system of the Frontier Pharmaceutical firm in New York, which is recommended also for stopping toothache. The local production of chlorine dioxide solves only the problem of durability, however, the chemicals needed for the ClO2 production still stay in the mixture.