Pulpal reactions to Trauma

Physical trauma in the form of accidents is very common, especially during adolescent period. Trauma can be with wear, erosion, orthodontic movements and other occlusal traumas. Many a times only quick orthodontic movements cause changes in the pulp dentin complex.

The extensive trauma involves avulsion or displacement of the jaw bones. The blood supply to the pulp is severed off. Either the pulp is necrosed with time or characterized by formation of hard tissues in the pulp chamber. These hard tissues have been labelled as ostodentin, because it has cellular infiltration similar to bone. In case of reimplantation, there occur degeneration of odontoblast and simultaneous loss of the adjacent cell free zone. This degeneration is accompanied by reduction of the width of predentin. In teeth with open apices, the odontoblasts can survive and produce reactionary dentin. Atypical interface dentin is formed separating the primary dentin and reparative dentin. The mechanism of cellular differentiation is similar to the avulsed and implanted teeth. The stimulation leads to differentiation of odontoblasts or odontoblast like cells.

With the orthodontic movements of teeth putting pressure more than required, there occurs increased blood flow in the pulp. Hyperemia has been shown to be more marked in teeth adjacent to the one where force is applied.

Hyperemia of the pulp in tooth undergoing orthodontic treatment

The orthodontic treatment is becoming more common in adults these days with the root fully formed. These teeth are likely to have more pulpal changes than the teeth in young individuals. The vacuolization of odontoblastic layer in the pulpal tissue is often the result when teeth are subjected to heavy forces. These changes are suggestive of degeneration of pulp. The impaired predentin formation is also suggestive of degenerative changes. After the force is removed, the predentin formation starts.