Various etiologic causes lead to dental pulp changes ranging from inflammation to necrosis. The most frequent changes, however, are caused by bacterial activity and toxins from carious process. According to the opinion of various authors and on the basis of our investigations the conclusion can be made that all the forms of dental pulp changes can be developed as the sequela of the disease of supporting apparatus. Pathohistologic examination of dental pulp of cariously damaged teeth showed that the occurred changes are mostly the sequela of inflammation and regressive and progressive changes are found as well.