Michigan Board of Examiners.

THE next meeting of the Michigan State Board of Dental Examiners will be held at the Dental College, University of Michigan, Ann Arbor, Mich., November 18 to 23, 1918, inclusive. Applications and other information may be obtained by addressing

B. S. SUTHERLAND, Sec'y,
Owosso, Mich.

Rhode Island Board of Registration. THE semi-annual meeting of the Rhode Island Board of Registration in Dentistry, for the examination of candidates, will be held at the State-house, Providence, R. I., December 3, 4, and 5, 1918.

Applications with fee must be in the hands of the secretary one week previous. For further information address

ERNEST A. CHARBONNEL, Sec'y, 139 Mathewson st., Providence, R. I.

Pennsylvania Board of Examiners.

THE next examination of the Pennsylvania Board of Dental Examiners will be held in Philadelphia and Pittsburgh, on Tuesday, Wednesday, Thursday, and Friday, December 3, 4, 5, and 6, 1918, at Musical Fund Hall in Philadelphia and the University of Pittsburgh, Pittsburgh. The practical examination will be held on Friday, December 6th, the last day. Application papers can be secured from the department of Public Instruction, Harrisburg.

For further information address

ALEXANDER H. REYNOLDS, 4630 Chester ave., Philadelphia, Pa.

New Jersey Board of Registration.

THE State Board of Registration and Examination in Dentistry of New Jersey will hold their annual meeting and examination in the Assembly chamber, at the State-house, Trenton, N. J., on December 2, 3, 4, 5, and 6, 1918. License fee, $25; re-examination fee, $10. Practical tests required: Insertion of an approximal gold filling, with approximating tooth in position, compound approximal amalgam filling, a silicate filling, practical test of the applicant's ability in oral prophylaxis, and preparation of a cavity for an inlay with wax pattern. Also the solder

ing of a bridge consisting of three or more teeth, exclusive of abutments, and one Richmond crown, which may be one of the abutments of the bridge; these must be made of gold or silver. The bridge must be struck from dies made from an impression of the mouth, and the articulating model, with the bridge, when soldered, must be submitted for inspection. An anatomical articulation of a full upper and lower set of teeth will also be required; teeth to be furnished by applicant. Wax bite properly trimmed and in place on models for inspection before setting up teeth.

Attention is directed to the following quotation from the dental law of New Jersey: "Applicant shall present to said board a certificate from the Commissioner of Education of this state, showing that before entering a dental college he or she had obtained an academic education consisting of a fouryear course of study in an approved public or private high school, or the equivalent thereof." In accordance with this law the secretary will issue application blanks only upon presentation of the required certificate from the Commissioner of Education, Statehouse, Trenton, N. J.

Note.-Dental Radiography will be added to the list of theoretical examinations in June 1919.

Applications must be filed complete ten days before the date of the examinations. Address all communications for further particulars to JOHN C. FORSYTH, Sec'y, 430 E. State st., Trenton, N. J.

Washington Board of Examiners. THE next meeting of the Washington State Board of Dental Examiners will be held in Spokane, Wash., November 20 to 25, 1918. FRANK B. LYNOTT, Sec'y, Spokane, Wash.

Montana Board of Examiners. OWING to the present war conditions and the lack of a sufficient number of applicants, the Montana Board of Dental Examiners will not hold the usual January examinations. The next examinations will be held at Helena, Mont., on July 14, 15, 16, and 17, 1919. T. M. HAMPTON, Sec'y, Helena, Mont.

Oklahoma Board of Examiners. THE Oklahoma Board of Dental Examiners will hold their next regular semi-annual meeting at the State Capitol building, Oklahoma City, Okla., beginning December 9, 1918. Reciprocity only with Kansas, Missouri, Arkansas, Nebraska, Indiana, and District of Columbia.

For further information address

H. OVERBEY, Sec'y,
Ryan, Okla.

California Board of Examiners. THE next meeting of the Board of Dental Examiners for the purpose of examining applicants for a license to practice dentistry in the State of California will be held in the City of San Francisco at the Dental College, University of California, beginning on December 9, 1918. All applications for examination must be filed with the board on December 9th at 9 A.M. Each application must be accompanied by (1) the fee of $25; (2) diploma and license from other states; (3) diploma from an accredited high school giving a four-year course of instruction or a certificate signed by a state superintendent of public instruction (or similar officer) to the effect that such applicant has had scholastic preparation in all respects equivalent to that demanded for graduation from an accredited high school giving a four-year course of instruction, in the state from which such certificate is issued; in lieu of such

No. 12

I

INTRODUCTION.

Na previous paper (DENTAL COSMOS, April 1917) the writer presented certain experimental data concerning the various methods involved in the process of electro-sterilization of infected root-canals. This procedure, from a clinical viewpoint, has been eminently successful; it presented, as the Editor of the DENTAL COSMOS expressed it, "a method of root-canal sterilization based upon scientific and clinical investigation that apparently brings the question of root-canal sterilization within the sphere of mathematical precision."

At the outset the writer wishes to state that every word he has uttered about electro-sterilization of root-canals still holds good today, and that he does not retract one iota from his previous statements. The reader may be justified in

VOL. LX.-73

asking this question: Why, then, this apparent paradox in recommending a new method, if the first method was successful? The perusal of the following lines, it is to be hoped, will quickly convince the inquirer that the new method in its final analysis is merely a simplification of the original method as discussed in the first paper, i.e. the utilization of chlorin as a disinfecting agent for the purpose in view.

During electro-sterilization, chlorin is obtained by a process of ionization of a sodium chlorid solution which requires an expensive apparatus, a knowledge of physical chemistry not possessed by the average dental practitioner, and an expenditure of valuable time. Especially the latter item is of the utmost importance to the busy clinician. The proper utilization of time constitutes the most important economic factor in the exer

1071

cise of any calling. Hence when a method promises to assist in the curtailment of time expenditure while producing equally good results as another given method, it is deserving of earnest consideration by the clinical practitioner.

The agent which the writer here wishes to discuss, and which he employs for the purpose of furnishing available chlorin, is a new compound known as dichloramin-T. This compound was selected by Dr. H. D. Dakin for the purpose of sterilizing infected war wounds. The testing of its surgical value was entrusted to Dr. Walter E. Lee of the Pennsylvania Hospital of Philadelphia and Dr. Joshua E. Sweet, professor of surgical research, University of Pennsylvania (now in France). Captain Sweet was kind enough to entrust the testing of this preparation, in regard to its value in dental practice, to the writer, who is also under much obligation to Dr. Lee for data concerning the general surgical technique, literature, etc. Following Dr. Dakin's instructions, dichloramin-T and its solvents were first prepared by Dr. B. M. Hendrix of the department of physiologic chemistry, University of Pennsylvania. The writer is deeply indebted to these gentlemen for numerous courteous acts.

HISTORY.

From an historical point of view it is interesting to observe that chlorin in the form of its numerous preparations has had a rather checkered career within that group of substances generically referred to as disinfectants and antiseptics. In 1788, the French chemist Berthollet obtained a liquid which exhibited marked bleaching and disinfecting properties, and Tennant of Glasgow, in 1798, prepared a more stable compound in the form of chlorinated lime for similar purposes.

In 1792, the Javelle works, near Paris, prepared a liquid bleaching compound for commercial purposes by passing chlorin into potash solution, which since has become widely known as Eau de Javelle or Javelle water. Again, in 1820, Labarraque, a French pharmacist, modi

fied this latter solution by substituting sodium carbonate for the potash salt. This solution, variously known as liqueur de Labarraque, as Labarraque's disinfectant fluid, or at present simply as Labarraque's solution, achieved great renown at the death of Louis XVIII, "for, thanks to the disinfecting and deodorizing values of his liqueur Labarraque was able to proceed with the embalming of the royal body, which was so profoundly decomposed that no one was able to approach it until after the application of the hypochlorite solution." (Dakin.)

When Semmelweiss, the assistant obstetrician of the Vienna lying-in hospital announced, in 1846, his epoch-making observation concerning the clinical causes of puerperal fever, he selected chlorinated lime solution as the agent par excellence for the destruction of that loathsome unknown "miasm" which was carried by the students, as he observed it, from the dissecting rooms to his wards, and which was the apparent cause of the scourge.

Again, during the civil war, chlorinated lime solutions were occasionally employed to check the frightful destruction of human life by hospital gangrene. However, principally on account of the caustic effect of the solutions employed, together with a faulty technique in its application, the compound never obtained the general usefulness which it rightly deserved. With the advent of modern bacteriology, chlorin has always been a favorite antiseptic in the hands of the experimental researcher, and within the province of the hygienist its application for the purification of drinking water and the sterilization of excreta it has achieved most remarkable results, and consequently it is at present very largely employed for such purposes.

Repeated attempts have been made in the past by bacteriologists to convince clinical surgeons and dentists that chlorin solutions are the acme of perfection as far as wound antiseptics are concerned. As a consequence, various preparations under more or less fanciful names have appeared on the market, among which Labarraque's solution, Ja

velle water, electrozone, dental meditrina, radizin, antiformin, eusol, eupad, chlorazene, and many others are examples. All of these solutions show remarkable activities as far as their laboratory tests are concerned; nevertheless, in their practical application they do not produce the same satisfactory results, and hence they have proved disappointing to the clinician. It should be borne in mind that most of these preparations are strong irritants, and that chlorin solutions are rather labile compounds; all of the solutions named lose their activity within a week or two, hence the disappointing results when commercial stock preparations are employed.

PHARMACOLOGY OF DICHLORAMIN-T.

The halogens represent the most interesting and incidentally the most important group of those chemical substances which as a class are referred to as wound antiseptics and as general disinfectants. On account of their general behavior bromin and fluorin are of less importance for such purposes, while iodin and chlorin, because of their high efficiency and their universal adaptability from a clinical point of view, form the most important group among these sub

stances.

At this moment chlorin is considered king among the chemical disinfectants; when freshly prepared, in the presence of moisture and a suitable temperature, it is the most active disinfectant known. From a technical point of view, however, numerous difficulties arise in its application which in the past have more or less interfered with its universal application. Chlorin as such is a gas which, while it may be readily compressed into a liquid, cannot be employed as such with any degree of satisfaction for wound. treatment, as it is too irritating. Suitable solutions prepared from the liquefied gas, a process which at present is very much simplified, possess necessarily all the drawbacks of an aqueous solution.

The usual solutions which have been most widely employed are Labarraque's

solution, i.e. a solution of chlorinated soda, and Javelle water. These two solutions, however, possess also serious drawbacks as far as their clinical application is concerned. They readily deteriorate, and, incidentally, they macerate the epidermis when kept in contact therewith even for a short time only, so as to render them practically not only useless but directly dangerous for the purpose for which they are intended.

Dakin in his studies of the antiseptic properties of the hypochlorite of soda solution finally succeeded in preparing a compound which is practically neutral and which incidentally contains only about per cent. of the hypochlorite salt. This solution produces virtually no irritating action on the skin and wound surfaces, and it is the compound which at present, according to the Carrel-Dehelly-Depage technique, is employed in the treatment of war wounds. Without entering into a discussion of the complicated and time-consuming technique of the above method as utilized in general surgery, it suffices to say that the method as well as the solution employed is practically useless for the treatment of infected root-canals.

Dakin soon realized the clinical drawbacks possessed by the various solutions of chlorinated soda, and his further studies led him to utilize certain synthetic chlorin compounds discovered by Chattaway, among which chloramin-T and dichloramin-T are the two most important representatives. Chloramin-T, being water-soluble, possesses more or less the same disadvantages as any other aqueous solution of chlorin. The permanence of such solutions is very limited, and, further, they are very quickly exhausted by wound secretions. On the other hand, dichloramin-T, a substance soluble in an oily medium, furnishes a veritable reservoir for the slow elimination of chlorin which preserves its activity for many hours in the presence of wound exudates. It is this latter substance which, upon the recommendation of Captain Sweet, we selected from the various chlorin compounds for our experimental work, and the results ob