No action for recovery of damages against a dentist, dental hygienist or dental assistant for personal injury, including death, allegedly suffered in the course of dental treatment, shall be brought after the expiration of 2 years from the date upon which such injury occurred; provided, however, that:
(1) Solely in the event of a personal injury the occurrence of which during such period of 2 years was unknown to and could not in the exercise of reasonable diligence have been discovered by the injured person, such action may be brought prior to the expiration of 3 years from the date upon which such injury occurred, and not thereafter; and
(2) A minor under the age of 6 years shall have until the latter time for bringing such an action as provided for in paragraph (1) of this section or until the minor’s sixth birthday to bring an action.