This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Terchloride of Phenol has recently been introduced as a disinfectant and antiseptic. It is prepared by passing a stream of chlorine gas through chemically pure carbolic acid, previously melted, until it acquires a violet hue. When carbolic acid is acted upon by chlorine gas a number of compounds are produced ; such as a monochloride, a bichloride and a tri- or terchloride of carbolic acid (phenol).
It is not an irritant, and has no acid reaction.
Terchloride of phenol is claimed to be a valuable antiseptic and disinfectant in the treatment of gangrenous ulcers, etc. In dental practice it has been very recently recommended in combination with iodoform, as a material for capping exposed pulps and as a filling for root canals of teeth, and the advantages claimed for it are, that it will be reabsorbed when in contact with living tissues; it is easily introduced into pulp canals; it absorbs exudations; it becomes hard when mixed with certain chemical substances, but is destroyed by pus; it is a very bad conductor of heat; and it is absolutely a non-irritant. The method recommended for its use as a capping and filling material is, to incorporate iodoform and terchloride of phenol with decalcified dead bone, as follows: dead bone or ivory shavings are decalcified in a ten per cent. solution of chemically pure hydrochloric acid, and after all the lime salts are extracted, the residue is collected upon a filter, washed, dried and rubbed to a fine powder in a porcelain or glass mortar. Upon this powder ten times its weight of a ten per cent. solution of iodoform in sulphuric ether is gradually poured and constantly rubbed until a fine yellow powder is obtained, which contains about fifty per cent. of iodoform. When used as a capping for pulps, or a filling material for root canals of teeth, this powder is made into a paste by the addition of carbolic acid or terchloride of phenol, being worked or rubbed together like ordinary cement.
For hyperaemic conditions of the dental pulp success has attended the application of a cap of the iodoform and decalcified bone paste mixed with terchloride of phenol. For inflamed pulps the application of terchloride of phenol is to be repeated every third or fifth day, until no more pain is felt, and the pulp is then to be capped with the decalcified bone, iodoform and terchloride of phenol material, and a temporary filling introduced into the crown cavity. The treatment of ulcerated and gangrenous pulps of the teeth consists in treating with the terchloride of phenol, and after the second or third application, if no trouble occurs from a temporary closure of the root canals, to fill with the decalcified bone, iodoform and terchloride material, using whalebone instruments for its introduction, until congelation is occasioned, and the congested condition of the capillaries of the part relieved, acting as a counter-irritant and antiphlogistic.