Eight years. In China, according to the provisions in the Catalogue of Medical Devices, oral CT equipment belongs to the third category of medical devices, and the mandatory retirement period is 8 years. When purchasing and using dental CT equipment, it is necessary to know the relevant regulations of the country or region, as well as the specific brand and quality of the equipment, so as to update the equipment before the end of the equipment life and ensure its safe, reliable and effective use.