论曰牙齿历蠹者，肾气虚弱，骨髓不固，气血衰耗，不能荣润于牙齿，故令牙齿黯黑，
谓之历蠹。
治牙齿历蠹黯黑。皂盐散方
皂荚（一挺酥炙去皮子） 盐花 槐白皮（各半两） 升麻 白矾（麸令汁枯） 甘松
香细
辛（去苗叶各一分）
上七味为细散，先以盐揩齿，后用药半钱匕，匀敷之。
治齿历蠹。谷精草散方
谷精草（烧灰） 白矾灰（一分） 蟾酥（一片炙干） 麝香（少许）
上四味，细研为散，于宣露处贴之。
治齿历蠹。柳枝膏方
柳枝（锉一握） 防风（去叉锉） 细辛（去苗叶锉） 盐花（各一分）
上四味，用水三盏，煎至一盏半，去滓更煎成膏，以瓷器收，每用薄纸，剪如柳叶，涂
药贴齿上。
治历齿蠹。麝香散方
麝香（一字） 定粉（一钱） 黄蜡（半两）
上先细研前二味，后熔蜡调之，摊在纸上，每临卧时，剪作片子，贴所患齿龈上。
治牙齿历蠹， 坏欲尽方
白矾（不拘多少）
上一味，新绵裹之，以所患齿咬定，有涎即吐。
治牙齿历蠹，齿根黯黑。升麻散方
升麻 槐枝灰（各半两） 白附子（炮） 密陀僧（ ） 露蜂房（各一分）
上五味为细散，入地黄汁一合，和匀阴干，每用揩齿。
治牙齿历蠹，齿根黯黑。胡桐泪散方
胡桐泪（一两） 丹砂（半两） 麝香（一分）
上三味，同研极细，常用揩齿。
Discussion: "Li Du" (gradual dental caries and blackening) of the teeth is caused by deficiency of Kidney Qi, instability of bone marrow, and depletion of Qi and Blood, which fail to nourish and moisten the teeth. Consequently, the teeth become dark and black, a condition termed "Li Du."
Formula for treating dental Li Du with darkening: Zaoyan San (Soap Pod Salt Powder)
Gleditsiae Fructus (one pod, roasted with butter, skin and seeds removed), Yanhua (Salt Flower), Huai Bai Pi (Bark of Sophora Root, half tael each), Shengma (Cimicifugae Rhizoma), Baifan (Alumen, bran-roasted until dry), Gansong (Nardostachyos Radix et Rhizoma), Xiang Xixin (Asari Radix et Rhizoma, stems and leaves removed, one fen each).
The above seven ingredients are ground into a fine powder. First, rub the teeth with salt, then apply half a qianbi (a small measuring spoon) of the medicine evenly to the affected area.
Formula for treating dental Li Du: Gujingcao San (Erythrostemonis Flos Powder)
Gujingcao (Flos Erythrostemonis, burnt to ash), Baifan Hui (Ash of Alumen, one fen), Chansu (Toad Venom, one piece, dried by roasting), Shexiang (Moschus, a small amount).
The above four ingredients are finely ground into a powder and applied to the exposed and damaged areas of the teeth.
Formula for treating dental Li Du: Liuzhi Gao (Willow Branch Ointment)
Liuzhi (Willow Twig, chopped, one handful), Fangfeng (Saposhnikoviae Radix, tips removed and chopped), Xixin (Asari Radix et Rhizoma, stems and leaves removed and chopped), Yanhua (Salt Flower, one fen each).
The above four ingredients are decocted in three cups of water until reduced to one and a half cups. The dregs are removed, and the liquid is further concentrated into an ointment. Store in a porcelain vessel. For use, cut thin paper into willow-leaf shapes, apply the medicine, and stick it onto the teeth.
Formula for treating dental Li Du: Shexiang San (Moschus Powder)
Shexiang (Moschus, one zi), Dingfen (Lead Carbonate, one qian), Huangla (Yellow Beeswax, half tael).
First, finely grind the first two ingredients. Then, melt the beeswax and mix with the powder. Spread the mixture on paper. Before going to bed at night, cut into pieces and apply to the gums of the affected teeth.
Formula for treating dental Li Du where teeth are severely damaged and nearly lost:
Baifan (Alumen, as needed).
Wrap this single ingredient in fresh cotton wool. Have the patient bite down firmly on the wrapped material with the affected tooth. Spit out any saliva produced.
Formula for treating dental Li Du with darkened tooth roots: Shengma San (Cimicifugae Rhizoma Powder)
Shengma (Cimicifugae Rhizoma), Huaizhi Hui (Ash of Sophora Twig, half tael each), Baifuzi (Aconiti Kusnezoffii Radix, processed), Mituoseng (Lithargyrum), Lufengfang (Vespa Nidus, one fen each).
The above five ingredients are ground into a fine powder. Add Yi Di Huang Zhi (Juice of Rehmannia Root) one he, mix evenly, and dry in the shade. Use to rub the teeth each time.
Formula for treating dental Li Du with darkened tooth roots: Hutonglei San (Liquidambar Resin Powder)
Hutonglei (Liquidambar Resin, one liang), Dansha (Cinnabar, half tael), Shexiang (Moschus, one fen).
The above three ingredients are ground together extremely finely. Use regularly to rub the teeth.