Root canal irrigation--a historical perspective

The concept of the germ theory of disease combined with the development of dentistry during the latter half of the 19th century had a direct effect on the practice of endodontics. The significance of root canal irrigation to endodontics strengthened in the period between 1859 when Taft recommended frequent syringing of the root canal to remove "irritants" until the mid-1940s when endodontics became a special field within dentistry and the American Endodontic Society was established. This paper reviews the role of irrigants and irrigation in root canal treatment during this period. A variety of recommendations on the use of solutions to clean root canals appeared in the dental literature, often innovative and at times entrepreneurial, but invariably empirically based. While it was widely assumed that by wiping the root canal with disinfectants sterilization would be achieved, many of the principles associated with cleaning the root canal published during this period, in particular by Willoughby Dayton Miller in the 1890s and Louis Grossman in the 1940s, remain equally relevant in the 21st century.