An oral device for checking a time to go to a dentist. The oral device includes a pH sensor configured to measure pH within an oral cavity, a housing on which the pH sensor is mounted, a processor configured to analyze measured pH from the pH sensor, and a wireless communication unit functionally connected to the processor and configured to perform communication with an external device. The oral device is useful for a patient who needs continuous management such as an implant surgery patient by allowing the patient to visually and easily check a time to go to a dentist and an individual oral condition of the patient. Further, by allowing the user to simply check the condition of the oral cavity at home, it is possible to more effectively manage the condition of the teeth and to save medical expenses.
