Medieval (12th-14th century) medical literature suggests that care of the teeth was largely limited to non-invasive treatment. Cures, mainly for toothache and "tooth worm" were based on herbal remedies, charms and amulets. Bloodletting was advised for certain types of toothache. There is also documentary evidence for powders to clean teeth and attempts at filling carious cavities. Surgical intervention for oral cancer and facial fracture is also known. Post-operative infection and abscess formation can be identified and early forms of false teeth are mentioned.