Design and construction of pain reductivesystem in dental injections

One of the main concerns of the referred subjects with dentistry is the fear from local anesthetic injection and its resulted pain. Physiologically vibration sensory inputs can block pain transmission. The aims of this study were design and make a vibrator device to reduce the pain of injection during dentistry procedures. A minute electrical motor was applied to the body of a syringe. The rate and power of vibration were adjustable by changing in motor voltage during the injection. In order to assess the heart rate, as a pain reaction indicator, a sensor was fixed to the tail of animal. The injections were carried out in the upper and lower jaws of male wistar rats(250-300 gr, 8 weeks old) in high and low vibration modes. The results were assessed and analyzed with Mat Lab software and T test. The results showed that in low vibration mode pain is less than at first and during the injection. A significant change was observed during 4 to6 seconds of injection (p<0.05) compare with control group. In high vibration mode, significant reductive change was observed in begin, during and pulling out the needle form gingival in compare with the control animals (p<0.05) According to results of our developed electrical injector device can be considered as an effective device without need to medical and psychological intervention in dental anesthesia.