Structurally, pulp stones can be classified as true and false pulp stones. True pulp stones are made up of dentine that is lined by odontoblast. True pulp stones are quite rare. On the other hand, false pulp stones are made up of concentric layers of mineralised tissue around blood thrombi, collagen fibres, or dying and dead cells. Histopathology
Histologically, there are two types of stones: (1) stones with regular calcifications (2) stones with irregular calcifications. For regular calcification, the pulp stones are smooth, round or ovoid with concentric laminations. It is commonly found in the coronal pulp. As for irregular calcifications without laminations, pulp stones may have the shape of rods or leaves and the surface is rough. It is more common in the radicular pulp. Pulp stones with regular calcification grow in size by addition of collagen fibrils to their surface, whereas the irregular type of pulp stones are formed by calcification of pre-existing collagen fibres. Pulp stones may also form around epithelial cells such as remnants of Hertwigs epithelial root sheath. It is presumed that epithelial remnants are able to induce adjacent mesenchymal stem cells to differentiate into odontoblasts. Associations
A pilot study was done with patients with cardiovascular disease (CVD) and it shows increased incidence of pulp stones in teeth with patients with CVD compared to healthy patients without CVD. There are also researchers which suggest the link between pulpal calcification and carotid artery calcification, despite not having a strong proof  on this correlation.
However, when the tooth concerned will undergo endodontic treatment such as root canal treatment, presence of large pulp stones will be clinically significant.Large pulp stones in the pulp chamber might block the access to canal orifices and prevent the exploring dental instruments from passaging down the canal. In these cases, burs or even ultrasonic instrumentation can be used to remove the blocking pulp stones. During the removal process, sodium hypochlorite which has dissolving action can also be used as a synergistic effect. == References ==