N.D. Cent. Code § 43-28-13

An individual who does not undertake the actual practice of dentistry within five years from the date of the individual's license and registration or any holder of any privilege related to the practice of dentistry shall, before engaging in the practice of dentistry in this state, notify the board of the intention in writing. The board, after a full investigation, may re-examine the individual as to the individual's qualifications to practice dentistry in this state, if the board deems such re-examination necessary. The failure of the individual to give the written notice to the board before engaging in the practice of dentistry in this state is grounds for disciplinary action.