B. Thomas
Oct 1, 1941
Citations
0
Influential Citations
22
Citations
Journal
Journal of Dental Research
Abstract
Phenol (carbolic acid) is a hydroxybenzene, C6H50H, first prepared by Runge in 1834 from coal tar, and by Church in pure form in 1871. Today phenol is obtained from coal tar or synthesized from benzene or a pure analine oil. It occurs as colorless needle-shaped crystals, with a characteristic odor and acrid, burning taste, and has a melting point of 40°C. Aqueous solutions contain 5 per cent or 90 per cent phenol; however it is soluble in glycerin, alcohol, fixed and volatile oils, ether and chloroform, and when first dissolved in glycerin or alcohol, phenol is freely miscible in aqueous solutions in any concentration. Since the antiseptic power of phenol depends on the entire molecule, its action as an antiseptic is not reduced when it is mixed with alcohol or glycerin. Although slightly acid to litmus, phenol is more closely related to the alcohols than acids. One of the more commonly used qualitative tests for the presence of phenol is the bromine water test. This test is accurate to approximately 1 part of phenol in 50,000 parts water. A saturated aqueous solution of bromine converts phenol into crystals of symmetrical tribromophenol. Certain compounds other than phenol, amines for example, also form precipitates with bromine water. The opinions of different persons regarding the method of application, the mode of action and the effect, as well as indications for and against the use of phenol in cavity sterilization (and desensitization) vary greatly. The method of using phenol most often depends upon previous teaching or clinical results, with its use on an empirical basis.