Which of the following is true of cellular cementum?

 # Which of the following is true of cellular cementum?

A. Forms during root formation

B. Forms after eruption of the tooth

C. Seen at the coronal portion of the tooth

D. Formation is a slow process

The correct answer is B. Forms after eruption of the tooth. 

The cellular cementum is also known as secondary cementum as this is formed later than the AEFC (Acellular Extrinsic Fiber Cementum). The cellular cementum found in the apical third is mainly of two types—the cellular mixed fiber cementum which forms the bulk of secondary cementum and occupies the apical interradicular regions and the CIFC (Cellular intrinsic fiber cementum) which is present in the middle and apical third. These types are mainly involved in the adaptation and repair of cementum. Since the secondary cementum is formed rapidly the incremental lines are placed further apart than in AEFC (Acellular Extrinsic Fiber Cementum).

Reference: Orban's Oral Histology and  Embryology