title: The significance of the presence of foreign material periapically as a cause of failure of root treatment.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003723:Dental Amalgam / Q000009:adverse effects; D003739:Dental Cementum; D003804:Dentin; D005260:Female; D005547:Foreign Bodies / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010486:Periapical Tissue; D012387:Root Canal Filling Materials / Q000009:adverse effects; D012390:Root Canal Therapy / Q000009:adverse effects*
chemical_list: D012387:Root Canal Filling Materials; D003723:Dental Amalgam