Structural Changes in Periapical and Other Oral Infectious Processes and Their Significance

THE JOURNAL of the AMERICAN DENTAL ASSOCIATION and THE DENTAL COSMOS Vol. 24

N O V E M B E R 1937

No. 11

STRUCTURAL CHANGES IN PERIAPICAL AND OTHER ORAL INFECTIOUS PROCESSES AND THEIR SIGNIFICANCE By E d w a r d H . H a t t o n , B.L., M .D ., Chicago,

in t r o d u c t io n

HE cellular structure in infectious processes has been under rather con­ stant scrutiny ever since the in­ troduction of the compound microscope and the more refined histologic methods. The relationship of the progressive tissue changes of the hosts to the life phases of the invading microorganisms has received too little consideration, on the one hand and, on the other, the little that is known has been overshadowed by acrimonious discussion based on conflicting experimen­ tal data. Only concerning such processes as tu­ berculosis have studies been made that are rather inclusive. In this disease, the situation is complicated, and there is a definite possibility that the process may be different from that in the majority of other infections. On the other hand, many phases of the mechanism of the disease

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(R ead before the Section on Therapeutics, Pathology and Research at the Seventy-Third Annual Midwinter Clinic o f the Chicago Den­ tal Society, February 1 7 , 1 9 3 7 .)

Jour. A .D .A . & D. Cos., Vol. 24, November 19 3 7

111.

have been very carefully studied. The infection develops slowly and, in this slow progression, there is abundant op­ portunity for the formation of rather permanent tissue records of the steps in the progression. It is known, for example, that the initial invasion differs from all subsequent ones, so much so that, in the lung, the first lesion is given a specific name and its characteristics are quite well understood. In this disease, live bacteria excite a different type of reaction from dead bacteria. The waxy material of the capsule acts differently from the proteins, and the types of these reactions have been studied and are known. The important matter is that the live organisms, the dead bodies of tubercle bacilli, the lipoid sub­ stance and the tuberculous proteins do call forth reactions of the cells and tissues of the host. These reactions, in addition, are highly characteristic and reflect in a most delicate fashion all of the factors pertaining both to host and to parasite and entering into the conditioning of the process in each individual case. Because 1749

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of this an d other examples, it is easy to believe th a t the tissues react in character­ istic ways to invasion b y b acteria an d to the presence of their products. O n the other h and, it is very difficult to believe th a t they do n o t react a t all to the pres­ ence of disease-producing bacteria in their midst. EVIDENCE OF INFECTION

This introduction m ay supply a suffi­ cient excuse to discuss tw o m atters which of themselves are n o t definitely related to each other. O ne of th em has to do w ith a grow ing tendency to accept as conclusive

of epithelium to or the hyperplasia of epithelium in these regions. Since these observations deal w ith bacteria and infec­ tion, this association is not so far-fetched. I n other papers read before this section, the m atter of the interpretation of cul­ tures m ade from extracted teeth has been discussed a t considerable length. In line w ith the preceding discussion, it should be said th a t too m uch attention has been paid to the bacteria obtained by such ex­ perim ents and too little to the tissue changes involved in the regions under study. F or instance, the situation has been dis­ cussed recently somewhat as follows : If th e apical regions of extracted teeth, to-

Fig. 2 .— V ery old periapical infection with marked detachment of peridental membrane. B, bacteria present. O , bacteria absent. Fig. i .— First o f a series o f periapical infec­ tions ; showing probable distribution o f bacteria in places marked B and absence o f bacteria in regions marked O . This is a very recent type of infection without much detachment o f the peridental membrane.

evidence of the presence of an infectious process the dem onstration of bacteria in these tissues or organs by cultural or stain­ ing m ethods. Even in the absence of either microscopic or gross changes in such organs an d tissues, this disclosure of bacteria is considered to be final. T he second m atter has to do w ith changes th a t take place in reactions to the presence of bacteria about teeth a fte r the m igration

gether w ith the tissues th a t m ay have re­ m ained attached to the teeth in the ex­ traction, be incubated for short periods in suitable culture m edia a fte r the extrac­ tion, bacteria m ay be dem onstrated in these tissues. I f bacteria are disclosed by suitable histologic and staining technic in this fashion, it is ra th e r conclusive evi­ dence th a t these tissues are infected re ­ gardless of the histologic picture, though perhaps n o t wholly regardless of the his­ tologic picture, because the more nearly norm al the picture, the m ore hazardous the situation. In such preparations, bac­ teria have been dem onstrated w ithin a

Hatton—Structural Changes in Oral Infectious Processes few cell layers of the surface of the alve­ olar process, only one, two or m ore cells away from the bone, b u t equally close to the torn m argin. Sim ilar cocci are dem ­ onstrated by these m ethods in regions in which there is a complete absence of tis­ sue reaction, but, generally speaking, close to the periphery of the granulom a ex­ tracted w ith the tooth. O n the other hand, such cocci are absent or n o t con­ spicuous in infiltrated regions or in ne­ crotic masses. From this and sim ilar dis­ cussions, one m ight well conclude th a t the one characteristic condition favoring b ac­ terial invasion of a hazardous type is ab­ sence of tissue reaction plus the recovery

concept, useful to both the clinician and the investigator. I t is useful to the clini­ cian for it supplies him w ith a yardstick by which he m ay m easure quite accu­ rately the extent of streptococcal pene­ tration and the n ature of tissue dam age as depicted by the x-rays. I t is useful to the bacteriologist and pathologist because it considers the nature of the streptococcal invasion from the biologic p o int of view. These authors argue that, in chronic proc-

Fig. 3 .— O ld fibrous periapical process, with just a suggestion o f epithelial proliferation at E. B, bacteria present. O , bacteria absent.

of bacteria by cultural methods or their dem onstration by staining the sectioned tissues. I t is refreshing indeed to contrast this discussion w ith the work of Fish an d M aclean which was published in the Septem ­ ber 1 5 , 1 9 3 6 , n um ber of the British Dental Journal. In particular, the attem p t of these authors to rationalize the biologic im plications of their experim ents should be praised. T h ey have constructed for the case of the chronic oral infections caused by streptococci a very satisfying

Fig. 4 .— O ld periapical infection with gan­ grenous pulp. There is no detachment of peridental membrane and n o infiltration in the fibrous granuloma. B, bacteria present. O , bacteria absent.

esses, the streptococci are lim ited in their distribution, except m om entarily, to foci of necrotic protoplasm and th a t they can­ not exist for long am ong norm al living cells. This m ay be restated by saying th a t the streptococci are never persistent inhab­

The Journal of the American Dental Association and The Dental Cosmos itants of living tissues, b u t always re­ quire necrotic and inert débris in w hich to grow an d to persist. According to them , the round-cell infiltration frequently en­ countered in these reactions is a response to toxic products em anating from strep­ tococci sheltered in these masses of dead protoplasm . Resorption of bone or bone sclerosis is produced by such toxic sub­ stances and not by the actual presence of the streptococci in the bone. T h e ab­ sence of such inflam m atory infiltrations and of bone changes is to be interpreted as significant of the absence of organisms

Fig. 5 .— O ld periapical infection, fibrous type, with beginning epithelial proliferation; the first stage o f formation o f a cyst. There is a strong probability o f the presence o f bacteria at B. Elsewhere, as at O , etc., bacteria are absent.

or toxic substances, or indeed the absence of both bacteria and irritatin g organic compounds, a t least those from diseasecausing germs. In other words, if a pulpless tooth is w ithout any changes to be noted by the x-rays either in the tooth or in the bone, provided the pictures cover enough ground, there is little probability of an infectious process being present.

T h ey have also studied the behavior of teeth in the tooth socket during forceps extraction with reference to the possi­ bility of aspiration of organisms from the gingival crevice into the socket. You are referred to this very excellent article for a detailed account of their experim ents in this p a rt of their investigation. These experiments seem to have been adequately controlled and carefully perform ed. Ac­ cording to the authors, organisms reach the apical region, the pulps and even the

Fig. 6 .— Fully developed dental root cyst, with cavity completely cut off from the root canal, at least at this level. B, bacteria present. O , bacteria absent. C , cyst cavity.

blood vessels during the course of a for­ ceps extraction. T hey believe th a t the bacteria are pum ped into these different places by m anipulation of the teeth d u r­ ing the act of extracting by the forceps m ethod. PERIAPICAL INFLAMMATIONS

These observations and conclusions are in harm ony w ith the d a ta already m en­

Hatton— Structural Changes in Oral Infectious Processes tioned, w hich some of us have presented to this society at form er sessions. W e have shown th a t cultures from the scrapings from the roots of teeth extracted by for­ ceps are alm ost uniform ly positive. This is also true of cultures m ade from the blood aspirated from the socket im m edi­ ately after the tooth is extracted. T he num ber of the bacteria recovered in this way is dependent largely on the degree of infestation of the gingival crevice and the am ount of m anipulation of the tooth required to dislodge it from the socket. We and others have shown th a t the only simulation of a correlation between bac-

Fig. 7 .— Longitudinal labiolingual surface of section through incisor and attached gingiva o f young dog. There is no subgingival space. G , gingiva. E, enamel. D , dentin.

teriologic findings an d those im plied by the study of roentgenogram s is found in the cases studied by m ethods which in ­ clude some adequate control of the m ate­ rial used for culture, as by sterilizing the outside of th e root before scrapings are removed for cultural purposes. In other words, all suspicion of contam ination m ust be elim inated before the d ata can be studied a t all. M aterial of an o th er source which tends

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to verify this position has to do w ith sec­ tions m ade from extracted teeth used for various purposes. This is especially true in those instances w herein it is known th a t careful preparation of the field from the aseptic point of view has n o t been m ade, and also in those instances in which it was know n th a t the gingival crevice was teem ing w ith bacteria a t the tim e of ex­ traction. I f these sections are stained for bacteria, an d often w hen routine staining m ethods are used, organisms are found in the m argins of peridental tissue torn off w ith the tooth. T h e position, of course, is

Fig. 8 .— Section shown in Figure 7 , illustrat­ ing separation of gingiva from enamel without force by a pointed probe. As soon as the probe is withdrawn, the position shown in Figure 7 is resumed. G , gingiva. P, probe. E , enamel. D , dentin.

adjacent to the outside surface, just in the same position for w hich such great significance has been claim ed by those w ho emphasize the im portance of the m ere presence of bacteria in tissues as conclusive proof of infection. These ob­ servations are not lim ited to our experi­ ence, b u t have been noted by others. T h e point of view based on these ob­

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served facts tends to elim inate the con­ tradictions and incongruities (and here I use th e w ord “incongruity,” also chosen by Fish an d M aclean) betw een the con­ clusions arrived a t on the basis of the ex­ am ination of these oral structures by bacteriologic, roentgenographic, histologic and clinical methods. T h e only conclu­ sion th a t would seem at all tenable is th at unless some w ay can be found to com­ pletely elim inate all suspicion of contam ­ ination in the culture of extracted teeth, bacteriologic exam ination of extracted

Fig. 9 .— Mesiodistal longitudinal surface of region between and including parts o f two incisors o f young dog. (Block fixed in 4 per cent formaldehyde solution.) T h e epithelium is not attached to the enamel or in approxima­ tion, except at the gingival crest, because of the shrinkage from fixation or postmortem con­ traction. S, space containing white flaky, soft debris. O , dentin. E, enamel. G , gingiva.

teeth should be com pletely abandoned. This includes cultures for diagnostic p u r­ poses, cultures to obtain m aterial for the prep aratio n of autogenous vaccines and cultures m ade in th e course of research. I t does seem th a t th e approach to the apical region through an incision into and

through the gingiva an d the alveolar proc­ ess has n o t been sufficiently explored. I regret th a t I am n o t able to subm it some figures w ith respect to this m ethod of ob­ taining m aterial fo r bacteriologic exam ­ ination, as was m y intention a t the time this pap er was first planned. C ultures m ay be m ade w ithout extraction, and al­ ways before extraction. Indeed, extraction m ay be indefinitely postponed. T he oper­ ation involves the surgical exposure of the apex through the buccal or labial sur­ faces, except in lingual roots. O n ex­ posure of the bone, the w ound should be re-treated w ith suitable germ icidal drugs, or in some other way to insure sterility, an d a new set of instrum ents should be used to replace those employed in the stages up to this point in the proce­ dure. F u rth er studies of the tissue changes in chronic oral streptococcic infections m ust be m ade w ith reference to the distribution and effect of the bacteria and their pro d ­ ucts in lesions of the type of those of • Fish and M aclean. C ertainly, sweeping deductions based on the dem onstration of bacteria in extracted teeth, and in the face of a conspicuous absence of inflam ­ m atory tissue changes, are not, in all cases, w arranted or are alm ost n o t w arranted, since the deduction th a t such teeth are wholly harmless m ight have a m easure of justification. GINGIVAL INFLAMMATIONS

In the study of specimens m ade by grinding whole frozen blocks of tissue, it has been found th a t the m echanical a t­ tachm ent of the epithelium to the enamel is very slight, indeed so slight as to be of little significance from the standpoint of w ithstanding m echanical traum a. I t is only the elasticity of the gingival fibers th a t holds the gingiva in close approx­ im ation to the enam el. O n the other h and, fluids do n o t pass into the region betw een the gingiva and the enam el with any greater ease th an by diffusion. In other words, dyes, suspensions, etc., seem

Hatton— Structural Changes in Oral Infectious Processes to reach the enamel surface quite as readily through the gingival tissues as along the enamel surface. This, of course, opens up a very interesting problem for investigation. Long before the idea of an epithelial attachment was conceived, it was known that the enamel surface in contact with the gingiva behaved quite differently from the enamel surface fully exposed in the mouth, and yet adjacent to the first mentioned surface. For exam­ ple, gingival third caries is sharply limited to surfaces not covered by intact gin­ giva. In connection with the combination of circumstances described in the preceding paragraph, one is reminded of the very interesting situation found in many in­ stances of hyperplastic pulps. In these, if the crowns are completely lost by caries, the robust, vascular granulation tissue, mushroom-like, spreads out over the root of the tooth. Usually, the outer surface of this polypoid mass acquires an epithe­ lial covering by extension or transplant from adjacent mucous membranes. The important matter is that the shelf of dentin covered by this mass is no longer susceptible to caries, the process of decay is arrested and the dentin becomes firm and eburnated. In sections made at such junctions, there is found not only an ab­ sence of caries of the dentin, but also some degree of attachment of the surface covered with epithelium to the dentin. This attachment or relationship is of no mechanical significance, but, what is more important, dental caries becomes inac­ tive beneath it. Neither does caries extend beneath the epithelial attachment of the gingivae. Another analogy is to be found in the transition of a periapical infection to a radicular cyst, by the replacement of the granulation tissue in this region by a cav­ ity surrounded by a sac made up of con­ nective tissue lined with epithelium. In the transition of the periapical infectious process to a cyst, the contents of the cyst cavity become sterile. In many instances,

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it has been demonstrated that in the de­ velopment of the condition out of the granulation tissue, the epithelium prolif­ erates close to denuded tissues at the apex of the tooth. Again, an epithelial rela­ tionship is formed, call it attachment or what you will, to the border of the de­ nuded surface of the tooth apex and ad­ jacent to the firm attachment of the peri­ dental membrane to cementum. As this relationship progresses and becomes per­ fected, the process is converted into one that is sterile both clinically and by bacteriologic test. Certainly, the environ­ ment within this epithelium-lined cavity is highly unfavorable for bacterial multi­ plication, or even persistence. These two phenomena just described have one factor in common with the con­ dition found underneath the epithelial attachment covering the enamel surfaces in the gingival region, the interrelation­ ship of tissue changes and the tendency to bacterial invasion. This is merely an extension of a principle that is well known; namely, that one of the most important barriers interposed between the hordes of bacteria outside the body and the more or less defenseless structures within the body has to do with epithelium. In these generalizations and in the plea that I am making for a more thorough study of the conditions that exist, per­ haps I am quite as guilty as those who would, it seems to me, condemn all pulpless teeth on what is, I believe, imma­ terial and irrelevant evidence; guilty of arriving at somewhat equally sweeping deductions based on equally inadequate data. But what we need most of all is more research like that done by Fish and Maclean in the field of chronic oral infec­ tions, by workers in the field of tubercu­ losis, etc. In spite of this, I am very much dis­ posed to accept the data and pictures supplied by Fish and Maclean, supple­ mented by our own bacteriologic and his­ tologic studies, as a very satisfactory foundation for the interpretation of clin­

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ical and roentgenographic symptomatol­ ogy in the management of sick people. The functional adjustments of the junction of epithelium and tooth sub­ stance is of much greater importance than the degree of mechanical attachment of

epithelium to enamel, cementum or den­ tin. Especially is this true with reference to bacteria and their disease-producing activities whether at the neck or at the apex of the tooth. 3 1 1 East Chicago Avenue.

WHAT DO YOUR PATIENTS KNOW ABOUT DENTISTRY? By E d w a r d J. R y a n , B.S., D .D .S., Evanston, III.

Q U E S T IO N N A IR E study was con­ ducted among patients in thirtyseven typical dental practices. Twelve hundred persons responded to twelve simple dental questions. Their re­ plies form the basis of the interpretation given in this article. In this study, an at­ tempt was made to discover what the average patient knew about dentistry. We wished to examine a cross-section of the attitudes of the American public with respect to their dental experience. We hoped from this study to be able to answer, in part at least, the question that you and I frequently ask, “What do my patients know about dentistry?” Twelve hundred adults answered this inquiry. They were among the patients of thirty-seven dentists practicing in hamlets, small cities and metropolitan communi­ ties. Every type of practice was repre­ sented, from those comprised of public relief clients to those of exclusive clientèle. The study was not confined to any single geographic area, but covered practices as widely separated as Holyoke, Mass., and San Francisco, Calif. ; from Fargo, N . D., to Wisner, La. The cooperating dentists did not select

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(R ead before the Section on Dental Eco­ nomics at the Seventy-Third Annual M idw in­ ter Clinic o f the Chicago Dental Society, Feb­ ruary 1 7 , 1 9 3 7 .)

Jour. A .D .A . & D. Cos., V ol. 24, November 19 3 7

the persons to receive the questionnaire, but presented it to the first fifty adult patients to come to each of their offices after the study was begun. The patient, without prompting by the dentist or his assistant, answered the twelve questions, and placed the questionnaire in an ad­ dressed, stamped envelope and mailed it to me. The cooperating dentists did not see the answers made by their patients. W e believe that a detailed study of the attitudes toward dentistry as expressed by 1,200 dental patients represents a fair sample and an adequate cross-section of opinion. It should be emphasized that the replies were made by dental patients whose knowledge of dentistry may be as­ sumed to be better than that of the non­ consumer of dental service. The facts are presented as revealed in the question­ naires, and the interpretations are based on these facts. In undertaking this study, we did not set out to prove or disprove anything. W e had no preconception to be bolstered and no prejudice to be dispelled. The report represents an exploration among the den­ tal beliefs of the American dental public at the present levels of culture. It is not scientific in the sense that it might prove or disprove a hypothesis, although the study and the tabulations were made with exacting care. It is not a presentation of