Research On The Effect Of Static Magnetic Field On The Growth Of Steptococcus Mutans And Bacillus Acidophilus In Vitro

Magnetic attachments are used more and more in stomatology clinical practice with their small size,simple operation and good retention. Static magnetic field has broad clinical application in prosthodontic and orthodontic fields as the magneic force generated by the static magnetic field is constant without decaying and easy to control.However, it will inevitably introduce external static magnetic field to the oral cavity when we use the magnetic attachments, there is a certain magnetic flux leakage phenomenon when we use the magnetic attachments. Present on the biological effects of static magnetic field has not yet achieved the same conclusion.It became a common concern of clinicians and patients whether the long-term effect of static magnetic field used in oral cavity would adversely affect the biology safety,Thus It's necessary to research the effect of dental magnetic attachments'static magnetic field on the microbiology balance.This research was designed to simulate the open, closed dental magnetic circuit of magnetic attachment,loading on the streptococcus mutans and lactobacillus acidophilus in vitro to study the effect of static magnetic field on the growth of both bacterium. It preliminarily study the effect of static magnetic field on the microecological balance of oral cavity and provide the theoretical basis for magnetic attachments application in oral cavity.In this study, streptococcus mutans and lactobacillus acidophilus cultures were exposed to the static magnetic field for 20h ,with the flux density of 12.5mT and 120 mT simulating of Magnedisc800 and Magfit EX600 magnetic attachments,controls were also set up.after 8 hours ,the bacterial growth amount was assayed by means of the OD value and counting the live bacterium amount every 2 hours.Finally,The growth curve was drawed for comparision .The study showed that,during the 20h loading time,1.12.5mT static magnetic field had no significant effect on the absorbance and viable cells of streptococcus mutans (P>0.05).2. The absorbance values and the viable bacteria number of 120mT magnetic field group of streptococcus mutans were lower than the control group (P <0.05).3. 12.5mT static magnetic field had no significant effect on the absorbance and viable cells of lactobacillus acidophilus (P>0.05).4. The absorbance values and the viable bacteria number of 120mT magnetic field group of lactobacillus acidophilus were lower than the control group (P <0.05).In summary, the study suggest that the leakage of the closed magnetic field with the strength of 12.5mT had no effect on the growth of streptococcus mutans and Lactobacillus acidophilus, which provide theoretical basis for clinical application. while the leakage of the open magnetic field with the strength of 120mT would inhibit the growth of the two bacterium, which showed that a high static magnetic field would adversely inhabit the growth of the two bacteria, suggesting that we should reduce the leakage of the magnetic field as much as possible during clinical application.Further study are needed to research the effect of static magnetic field on the metabolic response, gene mutation of oral flora to reveal the microbiological effects of it.