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f DT page 2A TK DT DENTAL TRIBUNE | March 2010 News 3A AD Plasma jets capable of obliterating tooth decay-causing bacteria could be an effective and less painful alternative to the dentist’s drill, according to a new study published in the February issue of the Journal of Medical Microbiology. Firing low-temperature plasma beams at dentin, the fibrous tooth structure underneath the enamel coat- ing, was found to reduce the amount of dental bacteria by up to 10,000- fold. The findings could mean plasma technology is used to remove infected tissue in tooth cavities, a practice that conventionally involves drilling into the tooth. Scientists at the Leibniz-Institute of Surface Modifications, in Leipzig, Ger- many, and dentists from the Saarland University, Homburg, Germany, tested the effectiveness of plasma against common oral pathogens including Streptococcus mutans and Lactobacil- lus casei. These bacteria form films on the surface of teeth and are capable of eroding tooth enamel and the den- tin below it to cause cavities. If left untreated this can lead to pain, tooth loss and sometimes severe gum infec- tions. In this study, the researchers infected dentin from extracted human molars with four strains of bacteria and then exposed it to plasma jets for six, 12 or 18 seconds. The longer the dentin was exposed to the plasma, the greater the amount of bacteria that were eliminated. Plasmas are known as the fourth state of matter after solids, liquids and gases and have an increasing number of technical and medical applications. Plasmas are common everywhere in the cosmos and are produced when high-energy processes strip atoms of one or more of their electrons. This forms high-temperature reactive oxy- gen species that are capable of destroy- ing microbes. These hot plasmas are already used to disinfect surgical instruments. Dr. Stefan Rupf from Saarland Uni- versity who led the research said that the recent development of cold plas- mas that have temperatures of around 40 degrees Celsius showed great promise for use in dentistry. “The low temperature means they can kill the microbes while preserving the tooth. The dental pulp at the center of the tooth, underneath the dentin, is linked to the blood supply and nerves, and heat damage to it must be avoided at all costs.” Rupf said using plasma technol- ogy to disinfect tooth cavities would be welcomed by patients as well as den- tists. “Drilling is a very uncomfortable and sometimes painful experience. Cold plasma, in contrast, is a complete- ly contact-free method that is highly effective. Presently, there is huge prog- ress being made in the field of plasma medicine and a clinical treatment for dental cavities can be expected within three to five years. Society for General Microbiology The Journal of Medical Microbiology provides high-quality comprehensive coverage of medical, dental and vet- erinary microbiology and infectious diseases. The original paper is avail- able on request. The Society for General Microbiol- ogy is the largest microbiology society in Europe, and has more than 5,500 members worldwide. The society pro- vides a common meeting ground for scientists working in research and in fields with applications in microbi- ology including medicine, veterinary medicine, pharmaceuticals, industry, agriculture, food, the environment and education. DT (Source: Society for General Microbiology) Plasma jets could replace dentist’s drill