318 
PATHOLOGY: J. A. MARSHALL 
Proc. N. a. S. 
teeth, the radioactive Hquid is forced into the infected area through the 
pulp canal of the tooth and allowed to remain for 24 hours. Subsequently 
the dressings are removed, the canals tested for sterihty and finally filled. 
With two possible exceptions there has been no evidence, after three years 
time, of succeeding soreness or pain. The individual dosage in terms of 
millicuries of gamma radiation has varied from .046 to .138. 
Failures in this method of treatment have been recorded but the fact 
remains that sterile tests have been obtained more often by using the radio- 
active solution than in similar experiments with other antiseptic agents. 
Summaries of experimental and clinical data are presented which indi-. 
cate the variations in the pathology, age of patient, etiology, treatment, 
clinical result and laboratory findings. 
In many instances tubes have been used in which de -emanation had 
proceeded to such a degree that it was not possible to obtain a reading by 
the electroscope. These have given similar results insofar as bactericidal 
action is concerned, but they have not caused the soreness which sometimes 
accompanies the use of solutions containing a recorded amount of gamma 
rays. 
In general the cases selected have been those in which previous treat- 
ments were without satisfactory result. Dichloramin T, formocresol 
beechwood cresote, phenol, and other antiseptics of a similar nature had 
been used without producing a noticeable change in condition. In fact, 
the greater majority of the cases carried a history of unsuccessful treatment. 
Most of them yielded to the action of the radioactive solution. 
The precautionary measures which are to be observed are naturally 
those referring to dosage and technique of application. Severe radium 
burns resulted in monkeys when emanation tubes containing eighteen 
millicuries were sealed into pulp canals of central incisors. These burns 
were so extreme that the hard palate and orbit were involved. It is be- 
lieved to be impracticable to use the radium except as a solution of the 
solids. The tubes should be thoroughly crushed under Ringer's solution 
exactly at the moment of use, and it has been customary to have three 
or four patients prepared and ready at one time in order to secure the 
greatest economy of material. The limited availability of de-emanated 
tubes except at emanation laboratories is a serious drawback to an exten- 
sive application of this therapy. However, it is planned, if funds become 
available, to further extend these researches to include not only additional 
data upon dosage but also to report upon the application of other radio- 
active preparations which may be found to be more plentifully distributed. 
^Marshall, John A., "Radium in Periapical Infections" {in press). 
2 Marshall, John A., "Bactericidal Action of Solutions of Radium Emanation," 
Cahf. State Med. J., Jan. 1922. 
