Avicenna minutely examines the various causes of odontalgia, and among them includes also the little worms by which the dental substance was supposed to be gnawed away. When a tooth becomes the seat of intense pain, accompanied by a throbbing feeling, Avicenna considers that this is due to an excessive accumulation of humors in the root; he therefore advises, as already Archigenes had done, the tooth to be drilled, in order to empty it, and afterward to introduce into it appropriate remedies. According to Avicenna, he who has a loosened tooth and desires to make it firm again, must avoid using it in mastication, must not touch it with the fingers, nor move it with the tongue; besides this, he must speak as little as possible, and make use of astringent remedies. To remove a tooth, Avicenna made use of either the forceps or the “eradicating remedies,” in which he, too, had full confidence. Like the greater part of his predecessors, Avicenna is of the opinion that the extraction of a firm tooth must be avoided as much as possible, as it may give place to an injury of the jaw, or become harmful to the visual organ, or bring on fever. On this point he remarks that, if an aching tooth appears to be sound, it is not always necessary to perform its extraction in order to cause even the most rebellious odontalgia to cease; in certain cases he obtained a complete cessation of the pain after having simply shaken the tooth without completing its extraction; which according to him was due to the double reason that by shaking the tooth a resolution of the morbid matter stagnating under it is provoked, and the action of the medicaments that are afterward made use of is thus favored. Among the eradicating remedies, the author enumerates white arsenic, orpiment, coloquintida, tithymallus, the fat of frogs, and others. He remarks, however, that before using them it is advantageous to detach the gum all around. Against the supposed worms in carious teeth, he praises fumigations made with the seeds of the hyoscyamus, garlic, or onion. Arsenic is used by him not only for the above-mentioned purpose, but also for the cure of fistulas and foul ulcers of the gums. When a tooth has become abnormally long, Avicenna makes use of the file to reduce it to a proper size; and in performing such an operation, he holds the tooth firmly between the fingers, or with a pair of pincers suited for the purpose. As a consecutive treatment, he prescribes frictions with alum, laurel berries, and aristolochia.[205] ABULCASIS. Among the Arabian authors, he who has the greatest importance in regard to dental art is undoubtedly Abulcasis (Abul-Casem-chalaf-ben-Abbas). Whilst Avicenna was one of the greatest physicians, Abulcasis was one of the greatest surgeons; and very justly he has been called the genius of Arabian surgery.