What typically causes reactionary haemorrhage after a dental procedure?

Reactionary haemorrhage is typically caused by a disturbance of the blood clot after the local anesthesia wears off. During a dental procedure, when a tooth is extracted, a blood clot forms in the socket to initiate the healing process and stop bleeding. The local anesthesia helps to manage pain during the procedure, but once it wears off, the patient may inadvertently disturb the clot, whether by biting on the area, spitting, or excessive movement of the tongue. These actions can lead to a dislodgment of the clot, resulting in renewed bleeding from the site.

This occurrence is often a concern shortly after the procedure, particularly within the first 24 hours, as this is when the clot is still fragile and healing is just beginning. Understanding this can help dental practitioners give proper post-operative instructions to patients to avoid activities that might lead to such complications, ensuring better healing and preventing reactionary haemorrhage.