High-tech dental lasers used mainly to prepare cavities for restoration can now help eliminate bacteria in root canals. Researchers in Austria credit the development of miniaturized, flexible fiber tips for enabling the laser to be used in endodontic (root canal) treatment. Dr. Ulrich Schoop and a team at the dental school at the University of Vienna used 60 extracted human teeth with one root each to test the effects of laser irradiation on root canals using an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser. The research is published in the July issue of The Journal of the American Dental Association (JADA). Schoop and colleagues inoculated the root canals with one of two types of bacteria (Enterococcus faecalis and Escherichia coli) then irradiated the canals using either a 1- or 1.5-W power setting. The team found that the laser reduced the amount of E. coli at the lower power setting and reduced it to below the detection level at the higher setting. It wsa also effective in eliminating E. faecalis. They also found that the laser removed the smear layer and debris from the root canal walls and that the temperature rise during irradiation was within safe borders. The authors said the Er,Cr:YSGG laser may be suitable for cleaning and disinfecting root canals and that it can be used safely if the common precautions for using lasers are observed and the energy levels and irradiation times are within the proposed range. They said clinical studies are needed to confirm their lab findings. In a related article in the JADA journal, Dr. Roy H. Stevens and colleagues at the Kornberg School of Dentistry, Temple University, describe their study of an Er,Cr:YSGG laser with a new tip that emits radiation radially. Stevens and colleagues examined the efficiency of this new laser tip in disinfecting root canal dentin walls infected with E. faecalis. They found that it significantly reduced the amount of E. faecalis in contaminated root canals. For more information, visit: http://ada.org