The Bacteriostatic and Bactericidal Effects of Radiation from Dental and Medical X-Rays

The purpose of this research was to proce or disprove the widely held beliefs that X-ray radiation used in medical or dental applications may affect the normal oral flora, and may also have effects on the micro-organisms existing in the oral cavity of every person. Such beliefs might be due to the common knowledge that radiation therapy has been utilized for the long time in the cancer patients to destroy the cancerous cells, and that radiation are also widely used in agriculture to prolong the shelf life of the farm products by destroying the decay-causing microorganisms existing in the agricultural products such as meats, produce, etc. Since very few research has been conducted in this concerned area, and not much pertinent information in the scientific literature could be found in this regard, a research experiment was set up to find out if these common beliefs have any merits. The research experiment involved selecting BDORT(By-digital O-Ring Test) positive dishes to incubate human saliva collected from a volunteer patient. Once dish served as control which was not subjected X-ray irradiation. Other dishes were subjected X-ray irradiation with various doses of irradiation strength at various time interval such as 1, 3, 5, 7, and 9 seconds to find out if any significant change taken place in the bacteria colonies. The bacterial colonies in the irradiated dishes then compared with that of the control dish so as to draw a conclusion if radiation for medical and dental X-ray machines would actually have any bactericidal or/and bacteriostatic effects on the oral micro-organisms flora. Finally, dishes were brought to a local hospital Radiology Department to use high dose of irradaition (used for cancer therapy) on the dishes to find out to what extent if such a high dose X-ray irradiation emitted from therapeutic cancer therapy machine would affect the number of bacterial colonies in the dishes as when compared with when dishes were under low doses of X-ray irradiation from dental or medical diagnostic X-ray machines. During the experiment, dishes, when irradiated, were sent to a certified medical technologist in the hospital laboratory to count the number of the bacterial colonies, and each change in the bacterial colony number were recorded in to data for biostatic analysis. The data were compared with BDORT negativity scores collected each time before and after dishes were irradiated, thus to find out if any corresponding confirmity between traditional laboratory findings and the score changes from BDORT findings. The results of this experiment revealed the fact that radiation from regular diagnostic X-ray machines possess little effect on bacteria, and that they have little effect on both cells and bacteria present in the human body. Neverthless, dramatically increasing the high radiation dosages does have potential to both inhibit and destroy bacteria. Therefore,using irradiation techniques to inhibit bacterial growth is only useful in agriculture practices, since tens of thousands of irradaiation dosages are necessary for bacteria inhibition. in human, over 500 RADs (radiation absorption dose) is lethal. Therefore, bacterial inhibition could not be practical in humans since it requires tens of thousands of RADs to be useful in the aspect.