The formation of a dental granuloma is primarily caused by infections and inflammation that affect the tissues surrounding the tooth. An article on villagedentalmedicine.com lists the main factors that contribute to the development of a
dental granuloma, including how the spread of infection from an inflamed nerve can trigger its formation and other causes. Pulpitis is one of the most common causes of a dental granuloma. It occurs when the pulp (the inner nerve and blood vessels of the tooth) becomes inflamed due to deep decay, trauma, or infection.