Abstract: This invention is an improved method and intra-oral device for smoking cessation or alcohol cessation. Specifically, this method requires the use of an intra-oral device comprised of a carbon monoxide sensor, ethanol sensor, sensor supervising and signal processing circuit, power source, electrodes, mounting element. The intra-oral device is used in association with the molar tooth via the mounting element which provides affixation to the device. During the process of smoking, the carbon monoxide sensor of the intra-oral device detects the threshold of carbon monoxide in the smoke entering the mouth. The sensor supervising and signal processing circuit is set into an activation mode, which triggers an electrical stimulation of the neck of the tooth via two electrodes of the device. During the process of alcohol consumption, the ethanol sensor of the intra-oral device detects the threshold of ethanol in the mouth.