Studies of Germicides for the Treatment of Root Canals*

STUDIES OF GERMICIDES FOR THE TREATMENT OF ROOT CANALS* By EDGAR D. COOLIDGE, B. S., D. D. S., Chicago, III. S T U D Y of antiseptics for the pur­ pose of sterilizing carious dentin was reported by W . D. M iller1 in 1891. One of his principal conclusions was that it requires much more time than we are accustomed to give to ster­ ilize carious dentin. The antiseptic should be sealed in the cavity and protected from the saliva for at least one-half hour. His observation also led him to the conclu­ sion that substances readily soluble in water have the most rapid action. The strength of antiseptics, principally essen­ tial oils, was reported in a very compre­ hensive manner two years earlier, in 1889, by G . V. Black.2 For his tests, the organisms used were those taken from the saliva. His report shows that some of the essential oils, such as oil of cassia, cinnamon, mustard and cloves, have a high range of antiseptic power, while others have none at all.

A

The test of the strength of a few of the drugs used at the present time for pulp treatment and for the sterilization of infected root canals was begun by us because of a desire to observe the action *F rom

th e

R esearch

N orth w estern 1. M i l l e r ,

U n iv e r s it y W .

D .:

L a b o ra to ry D e n ta l

of

the

S ch o o l.

C o m p a r a t iv e

R a p id it y

w it h W h i c h D iff e r e n t A n t is e p t ic s P e n e tr a te D e c a lc ifie d D e n tin , o r W hat A n t is e p t ic s

of these drugs on a mixed culture of or­ ganisms taken from a root canal of a tooth where an acute or chronic apical alveolar abscess or granuloma was in evi­ dence. The culture was taken after the rubber dam was placed and the surfaces of the exposed teeth were carefully cleaned with alcohol, after which they were painted with tincture of iodin. The tooth was carefully opened and the pulp chamber exposed, and the culture was taken from the apical portion of the canal. T h e mediums used for all cultures was the glucose-hormone brain broth3 used in the Research Laboratory at Northwestern University Dental School, similar to that recommended by E. C. Rosenow4 for culturing streptococci. The tests of this report were made along the lines suggested in the RidealW alker tests and in Hygienic Labora­ tory Bulletin No. 82 of the Bureau of Standards, Washington, D. C., April, 1912, so that a comparison might be made between these drugs, with phenol as a standard. The standard tests by which the phenol coefficient of drugs is determined are made by finding the dilu­ tion of a given drug that will kill Bacillus typhosus in a specified time, as compared to the dilution of phenol that will also kill the organism in that time. (Table 1.)

S h o u ld B e U s e d f o r S t e r iliz in g C a v it ie s B e ­ fo r e

F illin g ,

D e n t.

C osm os,

3 3 :337

(M a y )

1891. 2. B la c k , 3 :1 2 8

G.

(F e b . 15)

V .:

A n t is e p t ic s ,

1889.

Jour. A. D. A., A pril, ¡929

D e n t.

3. B a ile y , S a d ie F . : H o r m o n e M e d iu m s , J. I n fe c t . D is ., 3 6 :3 4 0 ( M a r c h ) 1925. 4. R o s e n o w ,

R e v .,

E.

C .:

S tu dies

on

E le c t iv e

L o c a l i z a t i o n , J . D e n t. R e s ., 1919, p . 205.

698

699

Coolidge— Studies o f Germicides

have as yet been identified as pathogenic. Many authors have reported such find­ ings, among which are Rosenow, Mayerhofer, Gilmer, Davis and Moorehead, Rickert and others. If phenol in a 1:100 dilution will destroy Bacillus typhosus in ten minutes at 20 C., it would be of in­ terest to know what dilution would be required to destroy a mixed culture taken from an abscessed tooth. The literature contains many reports of tests in which Bacillus typhosus and Bacillus coli have been used, but, so far, I have found no references to a culture being taken from

The phenol coefficient refers to the comparative strength of a drug against the organism with which the tests were made, and the value of the drug against other organisms is established only by tests made on them. The Committee on Standard Methods of Examining Disin­ fectants of the Laboratory Section of the American Public Health Association, at the annual meeting in 1917, recom­ mended “ the determination of the phenol coefficient against disease producing types of bacteria other than Bacilluj typhosus, particularly the ones against T a b l e 1.— M e t h o d

of

D e t e r m in in g

D is in fe c ta n t A

7 .5

2 .5

5

1 :80 1 :90 1 :1 0 0

+ +

—

—

+

+

1 :3 75 1:4 0 0 1 :450 1 :5 5 0 1 :600

■ + + +

S a m p le

P henol

C o e f f ic ie n t

of

a

G e r m ic id e *

T im e o f E x p o s u r e t o A c t io n o f D is in fe c t a n t in M in u te s

D ilu tio n

P henol

the

■ + +

10

1 2 .5

15

—

—

—

—

—

—

_ _

_

_

_

—

—

—

—

—

—

+ +

—

—

+

__ —

P h e n o l C o e ffic ie n t

550 — 100 = 5 .5

* T h e d ilu tio n o f th e u n k n o w n th a t w i l l d e s t r o y an o r g a n is m in a g i v e n tim e d i v i d e d b y the d ilu tio n o f p h e n o l th a t w ill d e s t r o y it in th e s a m e tim e g i v e s th e co e ffic ie n t o f th e u n k n o w n . • N a m e o f d is in fe c ta n t , A ; t e m p e r a t u r e o f m e d ic a t io n , 2 0 C . ; cu ltu r e u s e d , B . ty p h o s u s , t w e n t y -fo u r - h o u r e x t r a c t b r o t h f i l t e r e d ; p r o p o r t io n o f c u ltu r e a n d d is in fe c t a n t , 0.1 c .c . c u l ­ tu re to 5 c .c . d r u g s .

which the disinfectant is to be used.” 5 an abscessed tooth for such tests of The organisms found in a gangrenous germicidal strength. and putrefying pulp or in an abscessed A report by G. F. Reddish6 in 1927 tooth are not always the same, but the shows the results of tests made on staphy­ streptococci and staphylococci predom­ lococci at a temperature of 20 C. The dilu­ inate, while many varieties of bacilli and tion of phenol required to destroy the rods can be seen, only a few of which organisms varied with different strains, 5. R e d d is h , G . F . : E x a m in a t io n o f D i s in ­ but 1 :60 always destroyed them in ten f e c ta n ts , A m . J. P u b . H e a lt h , 1 7 :3 2 6 1927. '

(A p r il)

6. Footnote 5, p. 320.

700

T h e Journal of the American D en tal Association

minutes, w hile 1 :7 0 destroyed some strains in ten minutes. Hemolytic strep­ tococci were killed by a 1 :90 dilution in ten minutes, and pneumococci were killed by a 1:100 dilution in ten minutes. T E C H N IC

A ll of my tests were made in exactly the same way and under the same condi­ tions. Organic matter was used in all tests, as pulp treatment must be carried out in the presence of more or less or­ ganic matter, which reduces the effect of germicides. For this purpose, a similar amount of peptone and gelatin was used as that employed in the tests made by Feirer and Leonard7 with hexylresorcinol solution S. T . 37. In each test tube, 0.2 gm. of peptone and 0.1 gm. of gelatin was thoroughly shaken with 10 c.c. of the undiluted drug to be tested. This was tested or diluted with distilled wafer to the desired strength for the test. A ll tests were made in the proportion of 5 c.c. of solution inoculated with two standard loopfuls of a forty-eight-hour subculture taken from an original culture from the root canal of an abscessed tooth and transferred several times at forty-eighthour intervals before being used. The inoculated drug was then placed in a water bath and kept at 37 C. during the test. A t intervals of two and one-half minutes, as indicated in Table 2, a tube of culture mediums was inoculated and marked. After all inoculations were made, the tubes were incubated at 37 C. for five days and then examined by smear under the microscope. Phenol always killed the organisms in the dilution of 1 :80 in ten minutes. In four tests out of ten, the organisms were 7.

F e ir e r ,

W.

A .,

and

L eon a rd ,

V eader:

H e x y lr e s o r c in o l in O r a l A n t is e p s is w it h S p e ­ c ia l

R e fe r e n c e

C o s m o s , 6 8 :8 8 2

to

S o lu tio n

( S e p t .)

S. T .

1927.

37,

D e n t.

killed in 1:100 strength in ten minutes. Hexylresorcinol solution S. T . 37 killed the organisms in a dilution of 1 :5 in ten minutes by this test, which gives the solution a coefficient of 0.0625. It being a solution of 1:1,000 to start with, this would represent a dilution of 1 :5,000 and the coefficient for the solution would be 62.5. Trichlor killed the organisms in a dilution of 1:40 in ten minutes, giving it a coefficient of 0.5. The solu-

F ig .

1.— D ilu t io n s

g a n is m s f r o m

w h ic h

an in fe c t e d

d estroy

th e

or­

r o o t c a n a l in te n

m in u te s.

tion being 2 per cent to start with, this would represent a dilution of 1 :2,000 in the test and the coefficient would be 25. The solubility of cresatin in water at body temperature was found to be so low that the dilution was not germicidal in the time limit of this test. Many solvents were tried, the best of which were ace­ tone and benzene. Equal parts of ace­

701

Coolidge— Studies of Germicides

tone and cresatin could be diluted with water up to 1:10 and the solution was still germicidal in ten minutes. Cresatin killed the organisms in a dilution of 1 :60 in ten minutes when one part of benzene and 58 parts of distilled water was used, giving it a coefficient of 0.75. Oil of cloves in 1 :400 killed the organisms in ten minutes, showing a coefficient of 5.0. The same phenomena occurred with the power of oil of cloves as a germicide when one part of benzene was added as T

able

2- -Tests

of

G

it seems to raise their germicidal power greatly. (Fig. 1 and Table 2.) In an attempt to interpret these fig­ ures into terms of clinical application, it might seem that, because of the range of power of hexylresorcinol solution S. T . 37, it should greatly excel trichlor and cresatin for root canal treatment, since their strength is only about half that of phenol, while oil of cloves, with a coeffi­ cient of 5, would be about ten times as efficient as trichlor or cresatin. There

D ilution In f e c t e d R o o t C a n a l

ermicides for

that in

T

W

en

D

ill

M

e st roy

O rganisms

from an

inutes*

T im e o f E x p o s u re in M in u te s N a m e o f G e r m icid e

D ilu tio n

C o n tro l 1

P henol P henol P henol

1 :60 1:80 1:1 0 0

H e x y lr e s o r c in o l S. T . 37 1 :4 H e x y lr e s o r c in o l S. T . 37 1:5 H e x y lre s o r cin o l S. T . 37 1:6

2.5

5

7.5

10

12.5

15

+ + +

+ + +

+ + +

_

_

—

_

■ +

+ +

—

—

—

+

+

—

+ + +

+ + +

+ + +

+ + +

—

—

—

+ +

—

— —

+

— —

+ +

— —

— —

— —

+

—

—

— —

_ —

—

_

—

—

+

—

—

—

T r ic h lo r T r ic h lo r T r ic h lo r

1 :20 1 :40 1 :50

+ + +

+ + +

+ + +

+ + +

C resa tin C resa tin C resa tin

B en z en e 1, H -/J-28 B e n z e n e 1, IL 0 -4 8 B en z en e 1, H î O-58

+ + +

+ + +

+ +

+ + +

O il o f clo v e s O il o f clo v e s o f clo v e s

1 :300 1:400 1 :5 0 0

-i+ +

+ + +

+ + -f

Oil

* T e m p e r a t u r e , 37 C . ; cu ltu r e u sed , m ix e d cu ltu r e f r o m

—

—

—

_

+ +

+ +

—

+

P henol C o e ffi­ cie n t

0 .0 6 2 5 f

— 0 .5 0 0 0 Î

0 .7 5 0 0

_ —

■

5 .0 0 0 0

—

in f e c t e d r o o t c a n a l in h o r m o n e

b r a in b r o t h ; tim e, fo r t y - e i g h t h o u r s ; p r o p o r t io n o f c u ltu r e a n d g e r m ic id e , t w o s ta n d a r d lo o p ­ fu ls to 5 c .c . o f d ilu te d d r u g . f H e x y l r e s o r c i n o l s o lu tio n S. T . 37 is a 1 :1,000 s o lu tio n o f h e x y lr e s o r c in o l.

T h e d ilu tio n

a b o v e is r e a lly 1 :+,000, 1 :5,000, 1 :6,000 a n d the c o m p u t e d p h e n o l c o e ffic ie n t is 62.5 b y th is test. J T r i c h l o r h e r e is a 2 p e r ce n t s o lu tio n o f f u l l s tr e n g th t r ic h lo r .

The

d ilu tio n a b o v e is

r e a lly a 1 :1,000, 1 :2,000, 1 :2,500 a n d th e c o m p u t e d p h e n o l c o e fficie n t is 25.

was noticed when it was added to cresa­ tin. The dilution of oil of cloves 1 :800, of which one part was benzene, killed the organisms in ten minutes. Benzene alone has little germicidal power except in full strength. When added in very small amounts to cresatin or oil of cloves,

are other factors to be considered which have some relation to the clinical appli­ cation of these drugs in treating root canals. C L IN IC A L A P P L IC A T IO N

Two separate and distinct conditions must be recognized in the consideration

702

T he Journal of the American D ental Association

of root canal treatment : ( 1 ) the canal that contains living pulp tissue and (2 ) the canal that contains a gangrenous and infected material. Different stages of in­ flammation may co-exist in vital pulp tissue from a necrosis on the surface to a fibrous condition in the apical region. This tissue may be infected on the sur­ face and yet react to pain stimuli be­ neath. Such a pulp must be removed without pain to the patient and, at the same time, without carrying the surface infection into the periapical region. A t­ tempts to remove this pulp by any method without destroying the infection in the surface layer are sure to carry the or­ ganisms into the periapical region and result in tissue changes which are later revealed by the roentgenogram as rare­ fied or translucent areas. In this dis­ cussion, there will be no consideration of the requirements of the removal of liv­ ing pulp other than that which pertains to germicidal treatment before pulp re­ moval. Surface disinfection is essential to the success of operations in pulp re­ moval. Chemico-therapeutics seeks to produce the most efficient germicide that can be safely used on living tissue ; one that will destroy pathogenic bacteria in the short­ est space of time without arresting the vital reactions of the tissue. Bacteria and their poisonous products cause inflamma­ tion and death of living tissue. Germi­ cides are resisted by the tissue, and if they do not destroy the vital forces, they become changed and finally absorbed and carried away. In this process, bacteria that have been destroyed are also disposed of by the body cells. W hen this is ac­ complished, a return to normal follows. There are three important factors of germicidal action which must be observed in all cases as suggested by Hermann

Prinz:8 “ absolute contact, time during which the contact is maintained, and sufficient concentration of the employed antiseptic.” The principle of “ contact” brings up the question of the penetration of germi­ cides and the relative value of drugs in actually destroying organisms deeply seated in multi-canaliculated root canals containing gangrenous and putrescent or­ ganic material, and it is possible that some dentinal tubules might harbor or­ ganisms as well. Organisms protected by decomposed organic material must be reached by the germicide before they can be destroyed. The concentration of the drug and the time required to destroy the organisms must always be determined by laboratory tests to prove the efficiency of the treatment. In addition to these three principles, it is equally important that the germicide be not highly irritating to the tissue. The success of root canal treatment must be judged by the picture of the periapical tissue and bone as revealed by the roent­ genogram. Drug's that irritate severely are destructive and cause bone and tissue changes to appear in the periapical area9 which are extremely difficult to differen­ tiate from similar areas caused by toxic products of micro-organisms or by the organisms themselves. Organisms grow­ ing at the surface of an exposed pulp must be destroyed without causing pain when the germicide is sealed on the ex­ posed but still vital pulp. This is one of the most important steps in the treat­ ment of root canals, since the same or­ 8. P r in z , H e r m a n n : D is e a s e s o f th e S o ft T i s s u e o f th e T e e t h a n d T h e i r T r e a t m e n t , P h i l a d e lp h ia : L e a

& F e b ig e r ,

1928, p .

222.

9. L iith i, H . R . : T h e E ffe c t o f C h lo r p h e n o l, P h e n o l, T r i c r e s o l - F o r m a li n , b rech t’ s R oot P e r io d o n t iu m

T r io p a s te ,

“ A l­

F i llin g ” a n d E u g e n o l o n the o f D o g s , V ie r t e lja h r s s c h r . f .

Z a h n h e ilk ., 4 4 :9 6 , 1928.

703

Coolidge— Studies of Germicides ganisms may be found in carious dentin

treatment o f infected canals containing

and at the surface of the exposed pulp

organic matter. Another important consideration is the

as are found deeper in the root canal con­ taining a necrotic pulp.

F ig . 2.— C r o s s -s e c t io n

of

D rugs which

upper

b ic u s p id

length of time during which the germi-

root

s h o w in g

fiv e

c a n a ls .

The

p e n e tr a tio n

of

g e r m ic id e s in t o a ll a c c e s s o r y c a n a ls is n e c e s s a r y to d e s t r o y th e o r g a n is m s p re s e n t.

coagulate protein have only a shallow

cide is expected to remain active or un­

penetration and are not qualified for the

exhausted.

Some

drugs,

such

as

the

704

T h e Journal o f the American D en tal Association

chlorin preparations, have a short period of effect and must be replaced at rather short intervals owing to their great solu­ bility or chemical activity. Some drugs which are slowly soluble will remain ef­ fective longer because, as the active prin­ ciple is used in destroying the organisms, it will be replaced by the further solution of the substance. This is observed in such substances as thymol and cresatin. P E N E T R A T IO N O F G E R M IC ID E S

The penetration of germicides into the accessory canals branching off from the T

ab l e

3.— Su r f a c e T

ens ion of

with Henry’s law.” 10 This law refers to the distribution of a gas between a fluid and a gaseous phase proportionately to the pressure. Disinfection in principle is quite a similar process to the staining of micro­ organisms. Quoting from Bechhold: “ It follows from the ease with which they are stained that surface attraction is of great importance in the case of bacteria,, and in fact staining and disinfection are distinguished only by the fact that, in the latter instance, the absorbed sub-

So m e D r u g s a n d So l u t i o n E xpressed C entimeter*

in

D ynes

per

T e m p . (C .) A c e t ic

a c id

A ceton e A lc o h o l

(1 )

27.6

(1 ) . .................... ............... 20 (e t h y l) ( 1 ) . . . ............... 30

2 1 .4

................................ ............... 26 ................................ ............... 26 C re s o l (m e t a ) ( 1 ) ......................... 20 C r e o s o t e ................................ ............... 26

B enzene C r e s a t in

E th e r

(1 )

............................. ............... 20

H e x y lr e s o r c in o l (s o lu t io n S. T . 3 7 )

............... 29 ...................... ............... 26 S o d iu m o le a te sat. s o l . f T r i c h l o r .................................. ............... 26 M e r c u r y ( 1 ) ...................... ............... 15 E th y l a c e t a t e ...................... ............... 20 O il o f c lo v e s

T e m p . ( C .)

S .T .

............... ............... 20

23.7 30.0 37.7 37.4

W ater

...................... ............................. P h e n o l 9 5 % ( 1 ) . ............................. ............................. P h e n o l 1 :8 0 ( 1 ) P h e n o l 1 :1 0 0 ( 1 ) ............................. C r e s a tin ................. ............................. C r e s a t in 1 :100 . . . ............................. C r e s a t in 1 :100 . . .............................

26 30

57.0

20

61.1

29 29

37.7

B e n z e n e 1 :1 0 0 C r e s a t in 1 :50

. . . ............................. .............................

29

32.2 37.7

B e n z e n e 1 :5 0 C r e s a t in 1 :100

25.0 50.0

A ce to n e

....................• . . . 29 . . . ............................. 29 ............................. 29

1 :100

39.9

20

29 29

40.2 16.8

S. T . 72.4

52.3 45 .2 4 5 .2 44.6 4 4.6 4 9 .8 49.8

487.0 24.3

* T h e fig u r e s f o r a ll su b sta n ce s m a r k e d ( 1 ) w e r e ta k e n fr o m th e I n t e r n a t io n a l C r itic a l T a b le s , V o lu m e I V . T h e t e m p e r a t u r e g iv e n f o r a ll o t h e r liq u id s is th a t o f the r o o m r a th e r th a n o f the s u b sta n ce tested . * D u N o iiy , P . L . : A n A p p a r a t u s f o r M e a s u r i n g S u r fa c e T e n s io n , J. G e n . P h y s io l., 1919, p . 521. T h e s u r fa c e te n s io n o f th e d r u g s a n d s o lu tio n s w a s te ste d b y m e a n s o f th e D u N o iiy P r e c is io n T e n s io m e t e r . fH o d g m a n and L a n g :

H a n d B o o k o f C h e m is t r y a n d P h y s ics , E d it io n 2.

main canal (Fig. 2) is an important factor in preventing deep-seated infec­ tion from reaching the periodontal tissue at a later time, months or years after the root canal filling is completed. Disinfec­ tion takes place after the distribution of the drug. “ This distribution may occur either in the manner of a chemical com­ bination, adsorption or in accordance

stance exerts a particular poisonous ac­ tion on the micro-organism.” A germicide that lowers the surface tension of the medium tends to concen­ trate on the surface. It thus become? more destructive to organisms because 10.

B e c h h o ld , H . :

M e d ic in e , p. 391.

C o llo id s in B io l o g y anr*

Coolidge— Studies o f Germicides

more molecules are attracted to the sur­ face of the organism by adsorption (Fig. 3 ), and there is more rapid diffusion through the cell membrane. “ Any factor which might increase the number of mole­ cules of the germicide in contact with an organism at a given moment or which might accelerate their diffusion through this membrane would increase its bac­ tericidal efficiency.” 11 Surface tension as described by Bechhold, “ is that force that pulls toward the center of a drop of water that it may have the smallest surface possible.” 12 It can be easily measured by the force re­ quired to pull a ring or plate from the surface of a liquid or by the pull of a suspended drop of the liquid (the force equals the weight of the drop at the mo­ ment it falls). The liquid of low surface tension would drop faster and in smaller drops than one of high surface tension. The lifting force required to lift the ring from the surface of a liquid is expressed in dynes per centimeter of surface. One dyne represents 1/980 gm. of lifting force. Alcohols, phenols and soaps are among the more powerful surface ten­ sion reducing agents. Martin Frobisher, Jr.,13 demonstrated that the germicidal power of phenol and hexylresorcinol can be further increased by the addition of a definite amount of sodium oleate or ethyl acetate, which reduces their surface ten­ sion. Thus, a germicide which was de­ structive to organisms in ten minutes might be made effective in five minutes by the addition of a nongermicidal sub­ stance which would reduce its surface tension. (Table 3.) H . F o o t n o t e 7, p . 885. 1 2. F o o t n o t e 10, p . 16. 1 3. F r o b is h e r , M a r t in , J r . : th e and

R e la t io n s h ip th e

A c t io n

B e tw e e n of

S tu d ies

S u r fa c e

D is in fe c t a n ts

w it h

c ia l R e fe r e n c e to H e x y lr e s o r c in o l, t e r io l, 1 3 :1 6 3 ( M a r c h ) 1927.

u p on

T e n s io n J.

Spe­ B ac-

705

Frobisher states: “ Fluids of very low surface tension may, under some circum­ stances, permeate or penetrate into mi­ nute crevices or interstices more readily than fluids of high surface tension. The laws governing capillary rise and the lim­ itations due to viscosity must, of course, be considered when interpreting this generalization.” (p. 163.) “ Osmosis and diffusion are known to be materially accelerated under certain conditions by lowering the surface ten­ sion of fluids involved.” (p. 164.) “ Disinfectants which lower surface tension are adsorbed on the surfaces of the organisms to be killed and therefo.e exist in higher concentration at the most effective point.” (p. 164.) He also found that “ where an excess of solid surface tension reducent (like sodium oleate) is added to disinfectant solutions, enough reducent is adsorbed on the surface of the cells to prevent con­ tact of the disinfectant and the cell.” (p. 169.) “ There is reason to believe that the surface tension reducent induces changes in the permeability of the membrane, which facilitate the entrance of the drug into this membrane.” (p. 173.) The principle of the better penetrat­ ing power of liquids of low surface ten­ sion is more easily understood when one recalls how readily oil soaks into wood and alcohol or essential oils soak into woolen cloth, while water remains on the surface in drops for quite a time. (Fig. 4.) In the decomposition of the pulp tissue, besides nitrogenous products and gases, there is a certain amount of fat and fatty acid released or produced. An accessory canal containing any fatty matter (Figs. 5-6) would be more resistant to germi­ cides unless they either combine with the fat or dissolve it. Aqueous solutions

T he Journal of the American D ental Association

706

would scarcely penetrate, while fat sol­ vents might enter and allow germicidal contact with organisms thus protected. Soap, a product of fat and alkali, is use­ ful in freeing the surface of the skin from dirt by emulsifying the fat and re­ leasing the dirt which is incorporated in it. Fat solvent properties or substances which are readily soluble in fat and still retain their germicidal activity are essen­ tial in penetrating and disinfecting acces­ sory canals. It is important that a liquid wet the walls of the canal before it can enter.14 “ Liquids that do not wet the walls of the capillary not only do not rise in the tube but are depressed by it. In this case there is a layer of adsorbed air between the liquid and the tube.” 15 The measure of capillary rise of liquids

F ig . m ic id e s

3.— A d s o r p t io n , w h ic h

red u ce

by

b a c te r ia ,

s u r fa c e

d is p e r s io n o f m o lic u le s

of

penetrating, and they must wet the walls of the canal or tubule in order to enter. ( F i g -.4 - }

Clinical requirements and clinical re­ sults must be considered, as well as lab­ oratory tests; for it is often found that a drug with a very high phenol coefficient is not satisfactory in clinical practice. It is also found, in some cases, that a drug which has little effect on organisms in a test tube is very effective when injected into the tissue; for example, arsphenamin, a specific against Spirocheta pallida but unable to kill organisms in the test tube.lfi

ger­

te n s io n . L e ft ,

» -V

( + ) in s o lu tio n o f a

g e r m ic id e w h ic h d o e s n o t l o w e r s u r fa c e te n ­ s io n , s h o w i n g

equal

d is t r ib u t io n

th rou gh ou t

«.

£

the s o l u t i o n ; rig h t,_ m e c h a n ic a l a d s o r p t io n , b y b a c te r ia , o f g e r m ic id e s w h ic h l o w e r s u r­

of

fa c e te n s io n .

p la c e d a t p o i n t m a r k e d b y a r r o w

C o n c e n tr a t io n o f th e g e r m ic id e

F ig . 4 .— P e n e t r a t io n . lo w

s u rfa ce

te n s io n .

W e t t i n g b y a liq u id A

drop

of

w a ter

(le ft)

w ill

( - ) - ) o c c u r s a t th e m o s t e ffe c t iv e p o in t, i. e., o n th e s u r fa c e o f the o r g a n is m . T h e ra te o f

m en t is h e ld in a v e r t i c a l p o s it io n . A d r o p o f

d iffu s io n o f th e g e r m ic id e in to th e c e ll is a lso

liq u id

in c r e a s e d .

s a m e p o in t in th e in s tr u m e n t ( r i g h t ) w ill im m e d ia t e ly ru n d o w n to th e p o in t a n d d r o p

C osm os,

( F r o m F e ir e r a n d L e o n a r d , D e n t.

1927, p. 8 8 6 .)

r e m a in

a t th e s a m e p o in t w h e n th e in s tr u ­ of

lo w

s u r fa c e te n s io n

p la c e d

a t the

o ff w h e n h e ld in a v e r t ic a l p o s it io n . L iq u id s

in a capillary tube of known bore is an­ other method of measuring surface ten­ sion. Liquids of low surface tension are

o f lo w s u r f a c e te n s io n s h o u ld p e n e tra te m o r e

14. M c C l e n d o n and M edes: P h y s ic a l C h e m is t r y in B i o l o g y a n d M e d ic in e , p . 52.

Cresatin does not have a high phenol coefficient but has a very good clinical

r e a d ily in to c r e v ic e s a n d a c c e s s o r y c a n a ls if t h e y d o n o t c o a g u la t e p ro te in

(F ig . 7 ).

15. A lc o h o l is an e x a m p le o f a liq u id that r e a d ily w e t s a s u r fa c e . W a t e r w i l l n ot w e t it s o e a s ily , a n d m e r c u r y , n o t at a ll.

16. P ryd e, J oh n : c h e m is tr y , p . 322.

R e c e n t A d v a n c e in B io ­

C oohdye— Studies of Germicides

record. Oil of cloves shows a very good coefficient and seems more efficient clin­ ically than is generally considered. Tests made by MaW hinney17 in 1900 do not show the germicidal action of oil of cloves, and others have given similar re­ ports. Prinz18 states that essential oils are more irritating to the higher organ­ isms than to the lower forms of life and that continuous application will cause atrophy of the pulp. G. V. Black found that oil of cloves would prevent growth in culture mediums when diluted to 1 :1,200, while phenol only prevented growth in 1 :300. Benzene reduces the surface tension of other germicides and will dissolve fats, thereby assisting in penetration.

707

It seems that staphylococci and strep­ tococci are more resistent. As can be seen in Table 2, these tests gave it a phenol coefficient of 62.5. After the ad­ dition of the sixth group, the preparation becomes so nearly insoluble that it is of little value as a germicide. One of its most important characteristics is its power of reducing surface tension of liquids, which increases their penetrating power. The surface tension of the solu­ tion is expressed by the number 37. The surface tension of distilled water being about 72.4, it has close to one-half the surface tension of water. The samples used in this experiment tested 32.7 at room temperature. (Table 3.) Hexylresorcinol is nontoxic and, in

JOH Hexylresorcinol

'V-.CHg. CHg. CHg. CHg. CHg. CH3.

Hexylresorcinol solution S. T . 37 is a preparation containing one part of hexyl­ resorcinol dissolved in 300 parts of gly­ cerin and 700 parts of water. The drug is a crystalline substance only slightly soluble in water (1:1 ,5 0 0 ), but readily soluble in organic solvents. It is a syn­ thetic product built up by the addition of a group containing six carbon atoms to the resorcinol base or nucleus. W ith the addition of each methylene group, the germicidal power is increased until a phenol coefficient of over seventy times phenol is recorded for it. This coefficient was determined against Bacillus typhosus. 17. M a W h i n n e y , E . : D e n t. S oc., 1900, p . 125. 18. P r i n z , M e d ic a

T r.

H erm a n n :

a n d T h e r a p e u t ic s ,

I llin o is

D e n ta l

S tate

M a t e r ia

St. L o u is : C .

M o s b y C o m p a n y , 1926, p . 191.

V.

dilute solutions, is almost nonirritating to the tissue. It is used internally as well as externally. Solution 37 can be used in full strength in the mouth. It does not coagulate albumin and is very slightly affected by organic matter. It has many qualifications for a good rem­ edy for root canal treatment, but clinical experience is too limited to report at this time. Solution S. T . 37 has been a most satisfactory remedy when applied in di­ luted strength in infections of the soft tissue of the mouth and throat, or when injected in full strength into pyorrhea pockets after scaling of the teeth. The study of its properties has been very help­ ful in analyzing and comparing other agents which have given very excellent clinical results in root canal treatment.

708

T he Journal of the American D ental Association T R IC H L O R

Trichlor is an alkalinized solution containing sodium para toluene sulphon chloramid (chloramin T ) , sodium hypo­ chlorite and sodium chlorid. In 100 per cent strength, the solution is credited with a phenol coefficient of 50 when tested against typhoid organisms under the conditions of the Rideal-Walker test. It is a reasonably stable liquid, but should be preserved in colored bottles and kept from the light. It is reported

a phenol coefficient of 0.5 when tested against the mixed infection from an ab­ scessed tooth containing streptococci, staphylococci and rods. This solution de­ stroys the organisms in one minute. It has a surface tension of 50 (Table 3 ). It has a strong chemical affinity for pro­ toplasm and other organic matter. It is a solvent of pus and necrosed tissue and neutralizes toxic products of bacteria. “ According to Dakin and his collabora­ tors, chlorine forms chloramines when it

F ig . 5.— A p p e a r a n c e o f f a t d r o p le t s in th e o d o n t o b la s t p r o c e s s e s .

( F r o m E u le r a n d M e y e r ;

P a t h o h is t o lo g y o f th e T e e t h , p. 1 0 5 .)

to have between 11.5 and 13 per cent of active chlorin. It combines readily with tissue secretion and dissolves albumin. It acts by oxidation and chlorination after dissolving the surface envelop of the bac­ teria. It will prevent growth of bacteria in dilutions of 1:125,000. It is decom­ posed by alcohol. The solution available for use in den­ tistry and medicine known as trichlor is a 2 per cent solution. The report above (Table 2) shows this solution to have

acts upon protoplasm and these chlora­ mines have an antiseptic action.” 19 The solvent action of sodium hypo­ chlorite on albumin is a valuable prop­ erty where there is dead tissue which harbors anaerobes. This permits no or­ ganisms to escape, while if coagulating drugs are used, the surface of a necrotic mass becomes hardened and impermeable to the action of the drug. In the presence 19. F ootnote 10, p. 405.

709

Coolidge— Studies of Germicides

of blood or secretions, chlorin action is greatly reduced as are all other agents but in less proportion. Free chlorin oxidizes many organic compounds and liberates hydrochloric acid. (P N H 2+ C 1 .-V P N H C 1 + H C 1 .) TRICHLOR IN ROOT CANAL TREATMENT

In the treatment of gangrenous and putrescent root canals or after removal of an old root canal filling', trichlor is very effective. It dissolves albuminous matter and chlorinizes poisonous protein

be flooded after the necrotic tissue has been removed from the mouth of the canal, without disturbing the contents of the mid root. After absorbing the excess, a small pledget of cotton saturated with trichlor should be carefully sealed in the pulp chamber with cement. A t the second sitting, twenty-four hours later, the con­ tents of the canal may be safely removed by the usual curettement and mechanical treatment and the canal flooded with tri­ chlor again. The excess should be ab-

F ig . 6.— F in e f a t d r o p le t s in th e o d o n t o b la s t p r o c e s s e s .

decomposition products, releasing oxygen. Chlorin gas penetrates the canals and in­ accessible spaces. It neutralizes both toxic products and the gases of putrefaction. The treatment must be replaced fre­ quently, preferably every twenty-four hours, in order to renew the supply of free chlorin. In the prescribed strength, it rarely causes irritation to the soft tissue beyond the foramen. W hen applied on a vital pulp, it should be diluted to pre­ vent irritation. The pulp chamber should

(F r o m

E u le r a n d M e y e r ;

p. 1 0 5 .)

sorbed and an absorbent point carrying trichlor should be placed well up in the canal, but not far enough to come into contact with the vital tissue beyond the foramen. This should be allowed to re­ main twenty-four hours. A t the third sitting, the treatment should be varied according to the condition. If the canal is not free from odor, another treatment should be applied; but if free from odor and exudate, the canal may be filled. The absence of odor is not a positive proof of

710

T he Journal of the American D ental Association

cleanliness of the canal, but it is an aid in determining the proper time to fill the canal. Chlorin is a lymphagogue, and often the canal will be found very moist after the treatment has remained twentyfour hours. After the third treatment, if such a condition is found a sterile ab-

stable and uniform in strength. It is slightly soluble in water. It is readily soluble in organic solvents. It is a pene­ trating, slightly oily liquid having a sur­ face tension of 37.7 (Table 4.) It has a characteristic spicy odor which is rather persistent. It does not coagulate albumin

F ig . 7.— A c t io n o f v a r io u s d r u g s on e g g a lb u m in .

N o te d iffe r e n c e in r e a c t io n in the tu b es

i -8 a n d f r o m g - 14, ( F i g . 8 ) . A h e a v y c o a g u lu m is f o r m e d in th e tu b e s o f g r o u p 1- 8. I, a c e t o n e ; 2, a l c o h o l ; o il o f c l o v e s ; 4, b e e c h w o o d c r e o s o t e ; 5, c r e s o l ; 6, e u g e n o l ; 7 , p h e n o l 5 p e r c e n t ; 8, s u lp h u r ic a c id . F ig u r e 8 s h o w s 9, b e n s o l; 10, c r e s a t in ; 11, cr e sa tin in w a t e r ; 12, e u c a l y p t o l ; 13, h e x y lr e s o r c in o l s o lu tio n S. T . 3 7 ; 14, t r ic h lo r . A v e r y s lig h t c o a g u lu m o c c u r s in e u c a ly p t o l, a n d t r ic h lo r d is s o lv e s

a lb u m in .

T here

is h a r d ly a n y n o t ic e a b le c h a n g e in th e o t h e r tu b e s.

sorbent point may be sealed in the canal for twenty-four hours. It is a safe pre­ caution to seal a mild nonirritating ap­ plication in the canal for a few days before filling, such as eucalyptol com­ pound or cresatin; after which the canal may be filled. Chlorin is especially v: uable in treating the canal of a tooth which has become discolored, as it is also a bleaching agent. Chlorin acts on water and releases nascent oxygen, which de­ stroys the color molecule. (H ,0 -| -C 1 2 * 2 H C l+ 0 .)

3

CK

Cresatin.

0°

00CCH

Cresatin is the acetic acid ester of metacresol. It is a clear, colorless liquid,

F ig . 8.— D r u g s p - 14, r e fe r r e d to in F ig u r e 7.

and is not irritating to the tissue in full strength. It has an anodyne effect on living tissue. It is a surface tension reducent, and, in full strength, destroys

Coolidge— Studies o f Germicides

the organisms taken from an abscessed tooth in two and one-half minutes (Table 2.) If one part of benzene is added to one part of cresatin and diluted with fiftyeight parts of water, the phenol coeffi­ cient of the solution is 0.75. It is quite possible that its low surface tension and its ability to wet surfaces readily is the secret of its excellent clinical record. As it becomes hydrolyzed, there may be a very slow releasing of metacresol, which has a phenol coefficient against Bacillus typhosus of 2.4. The improvement in its germicidal effect by the addition of a small amount of benzene, which alone has very little germicidal action, is in T

able

4.— G

erm i c i d a l

711

greatly reduce germicidal action in that the fatty envelop protects the organisms from the germicide. Fat splvent prop­ erties are essential to thorough disinfec­ tion of inaccessible crevices and canals (Fig. 1 ). The slowly soluble property of cresatin gives it a prolonged action since the drug is not rapidly exhausted and the application may remain un­ changed if necessary for several days, this depending on the amount of exudate. Its anodyne effect and its prolonged action, together with its satisfactory germicidal effect, give it a wide range of usefulness in root canal treatment.

A cti on o f D r u g s in F u l l St r e n g t h a n d E f f e c t C resatin w i t h B e n z e n e or A c e t o n e

of

C ombining

P h e n o l 95 p e r c e n t ........................................................................................................................ L e ss th a n ten s e c o n d s A c e t o n e ................................................................................................................................. T w o a n d o n e -h a lf m in u te s B enzene

..........................................................................................................................

Two

and

o n e - h a l f m in u te s

C r e s a t in ................................................................................................................................. T w o a n d o n e - h a l f m in u te s H e x y lr e s o r c in o l S ol. S. T . 3 7 ................................................................................................. L e s s th a n on e m in u te O il o f c lo v e s ....................................................................................................................................L e s s th a n on e

m in u te

T r i c h l o r ..............................................................................................................................................L e s s th a n on e

m in u te

C r e s a t in a n d a c e to n e , e q u a l p a r t s ........................................................................................L e s s th a n on e

m in u te

C r e s a t in a n d b e n z e n e , e q u a l p a r t s ......................................................................................L e ss th a n o n e

m in u te

accordance with the findings of Frobisher on the increased germicidal effect of germicides by the addition of inert sur­ face tension reducents. CRESATIN IN ROOT CANAL TREATMENT

Cresatin is a very satisfactory remedy in root canal treatment. Every type of diseased pulp, from an aching exposed pulp to one chronically abscessed, has been treated with entire satisfaction with this drug. During the past year, it has been used in my practice in the propor­ tion of three parts of cresatin to one part of benzene. Aside from reducing surface tension, benzene is a fat solvent, increas­ ing the penetrating power of the germi­ cide into crevices and dentinal tubules by dissolving fatty substances. Oils and fats

SUMMARY

1. Important factors to be considered in determining the efficiency of a germi­ cide for root canal treatment are contact, time and concentration, penetration into inaccessible canals and crevices, duration of effect and irritation to vital tissue. 2. Both laboratory and clinical tests must be made to arrive at a satisfactory conclusion as to the merit of a germicide. 3. Any factor that increases the pene­ tration of a germicide into inaccessible canals and crevices is important. 4. Any factor that increases the num­ ber of molecules of a germicide in con­ tact with an organism at a given moment increases its power to destroy it.

712

T he Journal of the American D ental Association

5. Diffusion and osmosis may be in­ creased by lowering surface tension. 6. T h e action of fat solvents increases the possibility of penetration. 7. Drugs which coagulate albumin cannot penetrate deeply and are therefore not efficient germicides for root canal treatment. 8. Hexylresorcinol is a very powerful germicide, and is highly penetrating. It has a high phenol coefficient and a low surface tension. Its clinical tests confirm the laboratory findings and point to a wide range of usefulness in treating in­ fections of the soft tissue. 9. Trichlor acts by virtue of its chlorin penetration and chemical combination with decomposition products, replacing hydrogen and releasing nascent oxygen. It is very efficient as a germicide for gangrenous pulps and infected root canal treatment. For other mouth infections, it has a wide range of usefulness in proper dilution. It may be used with confidence in its germicidal efficiency. 10. Cresatin has a low surface tension and readily wets the surface. It is slowly soluble and penetrates deeply into in­ accessible spaces. It has a prolonged effect, and clinically appears to be non­ irritating in full strength to living tissue. It has anodyne properties which widen its range of usefulness from exposed in­ flamed pulps to those which are necrotic and infected. 11. O il of cloves, like other essential oils, contains irritating properties. It has a high phenol coefficient and low surface tension. It penetrates readily and has a prolonged effect. It has a history of long clinical use, but all laboratory reports do not agree on its efficiency as a germi­ cide in root canal treatment. 12. Benzene has a very low surface tension and little germicidal value. Its solvent action on fat and its power of

reducing surface tension of other agents, thereby increasing their action, appear to be its valuable properties. It should be used only in combination with other agents for treating root canals. DISCUSSION Carl J. G rove, St. Paul, M inn.: be

in t e r e s t in g

re s u lts

w o u ld

to

know

be

in

I t w o u ld w h a t the

d e fin ite ly

th e

v a r io u s

s ta g e s

of

p u lp d e c o m p o s it io n w it h the p r e s e n c e o f the p r o d u c t s f o r m e d b y th e a c t io n o f b a c te r ia , a n d w h a t th e e ffe c t o f th e c h e m ic a l r e a c t io n t a k in g p la c e in th e b r e a k in g d o w n o f the ele m e n ts c o m p o s in g th ese tissu e s w o u ld be, a s w e l l as th e s tr u ctu ra l d iffe r e n c e o f d e n tin , w h ic h w o u ld u n d o u b te d ly a lte r a c t io n w o u ld

the the

o f th ese a g e n ts to s o m e d e g r e e . It a ls o b e in t e r e s tin g t o le a r n to w h a t

e x t e n t th ese r e m e d ie s w o u ld p e n e tr a te th e tu b u le s a n d a ct o n th e b a c te r ia p r e s e n t in th e d e n tin .

D r . C o o li d g e is on e o f th e f e w

m e n in th e U n it e d b e l ie v e d be

th a t

not

extra cte d ,

S tates w h o h a v e all

and

I

p u lp le s s w is h

te e th

to

a lw a y s s h o u ld

express

my

a p p r e c ia t io n f o r th e p a r t h e ha s h a d in the w o r k o f b r i n g in g m a n y d e n tists t o r e a liz e that a ll su ch te e th a re n o t in fe c t io u s . T h e s tu d y o f g e r m ic id e s f o r th e t re a tm e n t o f in ­ fe c t e d and

root

c a n a ls

is

e x tr e m e ly

im p o r ta n t ,

it is o n ly t h r o u g h c a r e f u l in v e s t ig a tio n

th a t w e w i l l b e a b le to m a k e in t e llig e n t a p ­ p lic a t io n o f th e se a g e n ts . T h e p r e v e n t io n o f r e in f e c t io n o f th e d e n tin is a m a tte r that d e s e r v e s o u r a t t e n t i o n ; o t h e r w is e , tre a tm e n t s u ch as D r . C o o li d g e ha s o u t lin e d w o u ld be o f no

a v a il.

W e

m u st b e

a b le t o

se a l the

r o o t c a n a l at th e d e n t in o c e m e n t a l ju n c t io n , a n d i f th is is to b e d o n e , d e n tists m u st r e a liz e th a t it c a n o n ly b e a c c o m p lis h e d b y u s in g im p e r m e a b le m a t e r ia ls f o r fillin g r o o t ca n a ls . We

m u st

a lt e r e d

u se

m a t e r ia ls

b y th e f o r c e s

th a t

w ill

p r e s e n t in

not

be

th e tissu e.

I h a v e f o r s o m e tim e u s e d g o l d co n e s , o r w h a t m ig h t b e b e tte r te r m e d a g o l d ro o t c a n a l in la y . T h e f o r m s o f th e g o l d u s e d a re s t a n d a r d iz e d o r g a g e d to th e a p ic a l t h ir d o f th e r e a m e r s u s e d in s h a p in g th e r o o t c a n a l. In

o t h e r w o r d s , th e r o o t in la y is th e sa m e

d ia m e t e r as th e r e a m e r s . A c t u a l m e a s u r e ­ m e n ts o f th e le n g th o f th e r o o t as w e ll as th e d ia m e t e r o f th e a p ic a l t h ir d o f th e c a n a l h a v e b e e n c o m p ile d . T h e a v e r a g e le n g th a n d d ia m e t e r w a s d e t e r m in e d fin d in g s , a c h a r t s h o w in g the d ia m e t e r

of

a ll th e

ro o ts.

F rom

f r o m th ese le n g th a n d th e ch a r t,

713

Coolidge— Studies of Germicides

th e r e a m e r s in d ic a t e d , th u s a v o i d i n g th e use

th e s u g g e s t io n s t h e re in in t o d a ily p r a c t ic e a n d n o t c o n tin u e in th e u se o f u n d e s ir a b le m e th o d s . T h e e v id e n c e p re s e n t e d is c o n c l u ­

of

s iv e

o n e k n o w s the le n g th o f th e r o o t to b e o p ­ e r a te d o n . I h a v e a ls o in c lu d e d in th is c h a r t rea m ers

m u ch

la r g e r

o p e n in g o f th e c a n a l.

th a n

th e

n a tu r a l

T h e first step in this

te c h n ic is t o m a k e a s h o u ld e r in th e lo w e r p a rt o f

the p u lp

c h a m b e r b y u s in g an en d

c u tt in g o r in v e r t e d c o n e b u r . In o t h e r w o r d s , th e s h o u ld e r is m a d e a t th e u p p e r p a r t o f th e r o o t . f u r n is h

T h e p u r p o s e o f th is s h o u ld e r is to a

rest f o r

h o ld e r is m a d e

th e

r e a m e r h o ld e r .

t a p e r in g to th e

s iz e

The

of

the

b u r, w h ic h p e r m its it to p a ss in to th e p u lp c h a m b e r to rest on th e s h o u ld e r . T h e b o d y o f th e h a n d le h a s a g r o o v e e x t e n d in g into th e c e n te r , a n d o n e a c h s id e a v e r n i e r s ca le is

m ade

in

m illim e te r s ,

s in ce

a ll

m en ts o f ro o ts a re in m illim e te r s . ream er

or

th e

b roa ch

is

m easure­ W h e n the

in s e rte d

in to

the

h o ld e r , th e sh a n k o r th e u p p e r p a r t o f the r e a m e r ca n b e seen t h r o u g h th e g r o o v e in th e h a n d le . T h i s m a k e s it p o s s ib le to m a k e a r e a d i n g o f th e le n g th o f th e b r o a c h a n d to lo c k it in th e h o l d e r a t a n y d e s ir e d p oin t, this

d e p e n d in g

on

th e

le n g th

of

th e

to o th

to be o p e r a t e d o n , i n f o r m a t i o n w h ic h is o b ­ t a in e d f r o m th e r e f e r e n c e ch a r t. T h e b r o a c h

and

as

su ch

w h e th e r th e a p e x is r e a c h e d .

A

d e te r m in e fin e sm ooth

That

is

to

s a y , w e a r e lik e ly to u n d e re s tim a te th e im ­ p o r t a n c e o f a t h o r o u g h m e c h a n ic a l c le a n in g o f th e c a n a l, b e ca u s e , I s u p p o s e , t o o m u ch c o n fid e n c e is p la c e d o r t o o m u ch is e x p e c te d o f th e d r u g u s e d . I a m im p r e s s e d b y an d o ft e n r e f e r to a q u o t a t io n w h ic h is fo u n d ju s t b e n e a th th e title o f a l e a d in g te x t on “ M a te ria M e d ic a , P h a rm a co lo g y and T h e r a ­ p e u t ic s ,”

w h ic h

is :

“ D ru gs

so m e tim e s cu re ,

o ft e n r e lie v e , b u t a lw a y s c o n s o le .” I w as p a r t ic u l a r l y p le a s e d to h e a r D r . C o o li d g e m e n t io n

th e

fa ct

th a t

m any

p u lp s

m ay

be

n e c r o t ic in th e p u lp c h a m b e r o r th e first p o r t io n o f th e c a n a l a n d a t th e s a m e tim e b e v i t a l in th e

a p ic a l r e g io n , a n d th e n f o r

h im to in sist th a t a ll s u ch te e th b e o p e r a t e d on w it h o u t e ith e r in f e c t i n g o r p r o d u c in g a U n d o u b t e d ly ,

to

the

o f m o r e o r less tru e , a n d y e t I

more r a t h e r th a n th e less.

th e

c h e m ic a l

p o s it io n

In

a m s o m e tim e s le d to b e l ie v e th a t m a n y a t ­ te m p t s u ch m e d ic a t io n in the p r e s e n c e o f

ta k en w it h

in

n o n d e b a t a b le .

c a r r ie d o n in th e p r e s e n c e o r g a n i c m a t e r ia l. T h a t is

is in s e r te d in to th e c a n a l un til th e h o l d e r rests o n th e s h o u ld e r , w h e n a r o e n t g e n o g r a m is b roa ch

is

d e s c r ip t io n o f h is te c h n ic , D r . C o o li d g e s a id s o m e t h in g lik e t h is : A l l p u lp tre a tm e n t is

ir r it a t io n th e

of

th e

fa ilu r e

a p ic a l

to

p r e c a u t io n s is r e s p o n s ib le f o r

tissu e s.

observe

such

a la r g e n u m ­

b r o a c h is a lw a y s u s e d t o a v o i d i n ju r i n g the p e r ia p ic a l tis s u e . If th e ro e n tg e n o g ra m s h o w s th a t th e d e s ir e d p o in t h a s n o t b e e n

b e r o f u n s a t is fa c t o r y r e s u lts . T o illu s t r a t e : S o m e tim e a g o , a c a r e f u l c h e c k w a s m a d e o f a l a r g e n u m b e r o f c l i n i c a l ca s e s in w h ic h

r e a c h e d , w e a d ju s t th e b r o a c h as th e ca s e m a y r e q u ir e , a g a in in s e rt it in to th e c a n a l

v it a l

a n d ta k e a n o t h e r r o e n t g e n o g r a m .

s u rfa ce

I f th e p u lp

exposed

m e d ic a t io n

p u lp s

and

w ere

rem oved

in s tr u m e n ta tio n

in fe c t io n ,

and

we

to

fo u n d

d estroy

over

o f th e

in to

fa cto ry . D r . C o o li d g e h a s d e s c r ib e d the p h y s i o l o g i c a c t io n a n d t h e r a p e u t ic s o f th re e r e m e d ie s , n a m e ly , t r ic h lo r , c r e s a tin , and h e x y lr e s o r c in o l. T r i c h l o r is the o n l y o n e

th e

h o ld e r

to

th e

sam e

p o in t

as

the

o n th e s h o u ld e r .

S in ce a ll r o o t c a n a l in s tr u ­

m en ts a re m a d e th e s a m e le n g th , it is k n o w n th a t th e a p e x is r e a c h e d w it h o u t m a k in g an a d d it io n a l p ic tu r e , a n d it is a ls o k n o w n th a t p u lp is ju n c t io n .

rem oved to th e d e n tin o c e m e n ta l T h e r o o t i n l a y is a ls o in s e rte d

w ere

h a lf

is to b e r e m o v e d , a b a r b e d b r o a c h is in s e rte d p r e v io u s in s tr u m e n t a n d th e b r o a c h is in ­ s e r te d in to th e c a n a l u n til th e h o l d e r rests

e n tire n u m b e r t r e a t e d

w it h o u t

u n s a tis ­

w it h w h ic h I h a v e h a d s u fficie n t e x p e r ie n c e to v e n tu r e an o p in io n . I h a v e u s e d th is a q u e o u s s o lu tio n o f c h lo r in o v e r f o u r y e a r s , a n d I h a v e f o u n d it to b e a ll th a t L»i. C o o li d g e h a s s a id . It is s u p e r io r to th e oil

in to th e h o ld e r in sa m e m a n n e r a n d t o the

s o lu tio n

sa m e p o in t as th e in s tr u m e n ts.

b e u sed in th e tr e a tm e n t o f e ith e r v it a l o r n e c r o t ic p u lp s w it h o u t d e s t r o y in g th e p e r i ­

m a k es it p o s s ib le d e n t in o c e m e n t a l

a lw a y s

T h i s te ch n ic

to fill ju s t to the

ju n c t io n .

J. R. Blayney, Chicago, III.: D r . C o o lid g e ha s

ta k en

us

a n oth er

step

fo r w a r d

in

the

know n

as

d ic h lo r a m in -T .

It

m ay

a p ic a l tis s u e . W e w e r e t o ld to b e w a r e o f d r u g s th a t c o a g u la t e a lb u m in f o r t w o r e a ­ s o n s : first, b e c a u s e th e p r e c ip it a t e lim its the p o w e r o f p e n e t r a t io n , a n d , s e c o n d ly , b e c a u s e

s c ie n tific m a n a g e m e n t o f r o o t c a n a l th e r a p y ,

of

th e

a n d I h o p e th a t th ose w h o h a v e h e a r d t o d a y

to of

the v it a l tissu e w it h in the a p e x . N o n e th e c h lo r in - y i e l d in g c o m p o u n d s a ct in

a n d th ose w h o w ill re a d th is' p a p e r w ill put

danger

of

p r o d u c in g

s e r io u s

in ju r y

714

T h e Journal o f the American D en tal Association

s u ch a m a n n e r , s in c e a ll o f th e h a lo g e n s d e ­ s tr o y th e p r o t e in m o le c u le t h r o u g h the p r o c e s s o f s u b stitu tio n r a t h e r t h a n p r e c ip it a t io n .

Dr. Cooli'dge (clo s in g ): G r o v e ’s rem a rk s:

D u r in g

fillin g .

I

do

n o t th in k

th a t the

root can al

p r o b le m is e n t ir e ly d e p e n d e n t on a n e w m a ­ te r ia l f o r f i llin g r o o t c a n a ls . A g r e a t d e a l

R e f e r r i n g to D r .

d e p e n d s ' o n th e t h o r o u g h n e s s w it h w h ic h w e

th e

r e m o v e th e in f e c t io n

past yea r,

I

r ia l f r o m

a n d th e o r g a n i c m a t e ­

th e c a n a l, a n d th e n , o f c o u r s e , w e

h a v e h a d o c c a s io n to m a k e a c o n s id e r a b le s tu d y o f th e p u lp in r e la t io n to th e b u i l d in g

m u st in s e rt

u p o f a s e c o n d a r y d e n tin o r c e m e n tu m o r s o m e

fi l li n g as p o s s ib le .

f o r m o f b o n e s u b stitu tio n in th e r o o t c a n a l, a f t e r th e p u lp is r e m o v e d , w h ic h le d m e in to a v e r y in t e r e s t in g lin e o f stu d y , a n d as

s a v i n g teeth . T h i s s u b je c t is o n e o f th e m o st d is c u s s e d e v e n a f t e r a ll th e s e y e a r s . T h e r e

as n e a r ly

p e r fe c t a

W e

a re

m e c h a n ic a l

a ll in t e r e s te d in

is v e r y g o o d e v id e n c e th a t th e p r o f e s s i o n is

I w e n t b a c k o v e r th e lite r a t u r e , I f o u n d he h a d c o n tr ib u t e d m a n y a r t ic le s o n h is o w n

n o t s a tis fie d to r e m o v e p u lp le s s teeth . T o d a y ,

in v e s t ig a t io n s o f th a t s u b je c t , a n d m a n y fin e illu s t r a t io n s th a t h e lp e d m e g r e a t l y in m y

m oved;

m any

a re

rem oved

m any

th a t

b e in g

s h o u ld

rem oved

not

th a t

be

re­

a re

not

in ju r io u s t o h e a lth , b u t ju s t h o w to g e t th a t id e a to th e p r o fe s s io n w it h o u t h a v i n g th em

w o r k a n d d is c u s s io n o f th a t s u b je c t . A n d n o w h e b r in g s to us s o m e t h in g th a t r e p r e ­

g o t o o f a r in th e o t h e r d ir e c t io n is a d ifficu lt

sen ts a n o th e r id e a th a t p e r h a p s is g o i n g to

p r o b le m .

m a k e a c o n s id e r a b le im p r e s s io n , a n d th a t is h is i d e a o f c a s t i n g a r o o t fillin g . I d o n ’ t

and

k n o w h o w lim it e d th a t is in its a p p lic a t io n , b u t I s h a ll lo o k f o r w a r d w it h in te re s t to a

v a r i o u s l a b o r a t o r ie s .

c o m p le te p u b lis h e d d e s c r ip t io n o f D r . G r o v e ’ s

W e

m u st le a r n

d e t e r m in e

a p p ly th a n

th e

w hat

th in g s

to

how

to

extra ct,

b rou gh t

to

us

d ia g n o s e , and fro m

th en the

I h a v e le ss f e a r t o d a y

I h a d fiv e y e a r s

ago

a b o u t th e s a fe t y

p r e p a r a t io n o f th e c a n a l a n d o f th e c a s tin g

o f the r o o t c a n a l p r o p e r l y t r e a te d a n d fille d .

t o fit th e c a n a l a f t e r r e m o v i n g th e tissu es f r o m it a n d t r e a t in g it a n d p r e p a r i n g it f o r

I h a v e less h e s ita t io n o f s t a n d in g m y g r o u n d t o d a y th a n I h a d fiv e y e a r s a g o .

MORPHOLOGY AND GROWTH OF FUSIFORM ORGANISMS* By TH EO DO RE B . V O N BEU ST, Louisville, Ky. H E N plodding amid the laby­ rinths of a research problem, the hopeful worker sometimes expe­ riences a thrill. N ot uncommonly, thrills constitute the student’s only re­ ward. W hile experimenting in 1905, in an attempt to disclose the morphology

W

* W o r k s u p p o r t e d , in p a r t , b y a g r a n t fr o m the R e s e a r c h C o m m is s io n D e n t a l A s s o c ia t io n . *R ead

b e fo re

P h y s io lo g y , C h e m is t r y A nnual

S e c tio n

P a t h o lo g y , (R e s e a r c h )

S e ss io n

A s s o c ia t io n ,

th e

of

of

th e

M in n e a p o lis ,

1928.

Jour. A. D. A., A pril, 1929

th e

A m e r ic a n

on

H is t o lo g y ,

B a c t e r io l o g y and at th e S ev e n tie th A m e r ic a n M in n .,

D e n ta l

A ug.

22,

of the spores of Leptothrix racemosa Vicentini, I unintentionally divested of their enveloping mantle o f stain the in­ terior of certain micro-organismal clumps found in tooth felt. The ensuing thrill resulted in a number of publications,1 in which the organism Leptothrix falciformis was described. These investiga­ tions have not, to my knowledge, been commented on. In view of the resem­ blance of certain developmental forms 1. N o.

V o n B e u s t, T . B . : 5,

1906;

D e n t. F if t h

A r c h . f . Z a h n h e ilk .,

C osm os,

5 0 :5 9 4

(J u n e )

In tern a t.

C o n g .,

B e r lin ,

1908;

P roc.

1909;

D e n t. R e v ., 2 6 :1 1 7

( F e b .)

1912.