This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Tri-chloride of iodine is antiseptic and disinfectant, being highly efficient as such, through the liberation of chlorine, whose nascent energetic effect is still further enhanced by the presence of iodine. The antiseptic power of tri-chloride of iodine was officially tested by the Imperial Sanitary Bureau of Germany, and the following result was ascertained: "An aqueous solution of 1 in 1000 destroys resistent bacillus-spores within a comparatively short time; but only the aqueous solution does this. Alcoholic or oily solutions proved ineffective. Iodine tri-chloride far surpasses carbolic acid, and is next to corrosive sublimate (bi-chloride of mercury), in antiseptic power." It may be obtained in quantities of ten grammes in hermetically sealed tubes, and is best kept in five per cent. aqueous solutions which appear to remain unchanged for some months. Langebuch claims that a o.i to 0.15 per cent. solution is equal in antiseptic action to a 0.5 to 1.0 per cent solution of bi-chloride of mercury; in other words, that it is about five times as efficient as the bi-chloride. It is also claimed to be relatively the least poisonous of all antiseptics. Behring found that in aqueous solutions, having equal action upon the spores of anthrax bacilli, sublimate is five to six times, and carbolic acid and creasote seven to eight times, as poisonous as the tri-chloride.
Dr. W. D. Miller says: "We have consequently reasons to hope that the tri-chloride of iodine may prove a valuable remedy in the treatment of diseased conditions of the teeth and mouth." Its efficiency as a disinfectant for carious dentine has been clearly shown in the experiments of Dr. Miller, and his impression was that the five per cent. solution of the trichloride of iodine is one of the most active agents for sterilizing carious cavities, and disinfecting carious dentine preparatory to filling teeth.