(a) A registration under this chapter is valid for two years.
(b) A dental assistant may renew a registration by paying the required renewal fee and complying with any other renewal requirements established by the board.

(c) A dental assistant whose registration has expired may not engage in an activity that requires registration until the registration has been renewed.
(d) The board by rule may adopt a system under which registrations expire on various dates during the year. For the year in which the expiration date is changed, the board shall prorate registration fees on a monthly basis so that each registration holder pays only that portion of the registration fee that is allocable to the number of months during which the registration is valid. On renewal of the registration on the new expiration date, the total renewal fee is payable.