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A study of some factors associated with endodontic “flare-ups”
A study of somefactors associatedwith endodontic “flare-ups” Henry A. Burtels, D.D.S.,” Irving J. Na,idorf, D.D.S.,#* and Harry Blechman, D.D.S., M.A.,*** New York, N. Y. DEPARTMEXT
OF MICROBIOLOGY,
UNIVERSITY,
AND
DEPARTMENT
DENTAL
ORAL
SURGERY,
AND
COLLEGE
OF DENTlSTRY,
OF RESTORATIVE COLUMBIA
NFJV
DEXTISTRY,
YORK
SCHOOL
OF
UTIVERSITY
A
study was undertaken by the T&State Society of Endodontism to determine the causative factors of Wflare-ups” which occur during endodontic therapy. A “flare-up” was defined as a condition of pain or swelling resulting in an emergency (nonroutine or nonscheduled) visit. Smears and cultures from such cases, together with a questionnaire, were forwarded to the Department of Microbiology, College of Dentistry, New York University, for examination. From the data submitted, detailed information was obtained relative to the tooth involved, previous history of duration and degree of pain, apical penetration during instrumentation, periodontal lesions, and type of treatment and medication. An x-ray film was also submitted for examination. The study included 196 specimens, and the conclusions and tabulations presented here reflect the results of the bacteriologic examinations and the clinical dat,a submitted. Since the data were not always properly recorded by the participants in the study, a number of questionnaires were invalidated in one or more categories. For example, some cultures arrived with no histories or with incomplete data; others were broken during transit, as a result of improper packing; and in some instances x-ray films were not submitted. Thus, in the accompanying tables the total numbers of cases in various categories are not identical. *Associate Clinical Professor, Department of Microbiology, **Associate Clinical Professor, Department of Restorative tion, Columbia University. ***Acting Dean and Professor, Department of Microbiology,
New York University. Dentistry, Endodontie New
Pork
Pec-
IJniversity.
255
03, ox & 02. Fehruar~, 1968
MATERIALS AND METHODS
Each dentist was supplied with kits consisting of a qucstionnairc, a glass slide on which exudate or transudate from the canal was to be smeared, and a screw-capped tube containing trypticase soy broth with 0.1 per cent agar for cuburing. The smear and culture were securely wrapped, placed in a standard mailing carton, and forwarded by first class mail. The smear was stained by Gram’s method and examined for microorganisms and the presence of leukocytes. If no growth occurred, the cultures were incubated at least 10 days before being discarded. When growth occurred in the broth, subcultures were made to appropriate media for isolation and identification of the isolates. RESULTS
The data obtained from a study of the questionnaires submitted and the results of the microbiologic examinations are given in the accompanying tables. Only twenty-six of the 125 endodontists with membership in the Society submitted specimens, and of the 196 specimens submitted, four fifths (161) were forwarded by sixteen members. Thirty-one of the specimens were invalidated as a result of being broken in transit or because smears were submitted without cultures. Of the remaining 165 cultures, 141 (85 per cent) were received within 4 days, so that extended delay in transit was not a factor in the retardation of growth. In the remaining 15 per cent of the specimens, however, delays of 7 days to 3 weeks occurred, as most of the specimens were mailed during the holiday season. Among the 113 cultures which arrived at the laboratory without any apparent growth, a uniform turbidity or granular growth developed within an incubation period of 48 hours in sixty-two (55 per cent), after 4 days of incubation in two, and after 8 days of incubation in two. The remaining forty-seven cultures were maintained at 37O C. incubation for a minimum of 10 days before being discarded and reported as “NO growth of microorganisms occurred.” Table 1.Appearance of culture on arrival Clear (no observable Cloudy (growth)
113 specimens 52 specimens
growth) Total
5%
II. Microscopic examination of smears submitted with the “no growth” cultures
Table
Polymorphmuclear leukocytes None Few Moderate Many Totals
Nicroorganimns Specimens
None
4 6
2 4 ;
5 9 -iG
1
Few 1
i
present
in smears
) Moderate
1
&fany
1 0 :
0 0
0
7 a
-z-
0 -i-
0
Volume 25 Number 2
Factors associated with emiodontic “flare-ups”
257
The forty-seven cultures which gave no evidence of growth during a minimum 10 day period of incubation were found in thirty-four instances (72.3 per cent) to have been in transit 4 days or less. The “no growth” specimens were studied further to determine whether the smear preparations accompanying them would afford any significant data in relation to microorganisms and the inflammatory reaction. Unfortunately, smears were not forwarded in ten instances, whereas in another twelve cases t,he smears contained insufficient material, and one slide was broken in transit,. Apparently, in eight of the twenty-four specimens no microorganisms were seen. A few organisms were found in thirteen of the smears, and in only three were a moderate number present. The number of polymorphonuclear leukocytes varied from none to many. Many leukocytes were present in nine smears, but in seven of these only a few microorganisms were observed. In one of the remaining two smears no organisms were found, while in the other a moderate number were observed. Since no growth was obtained in cultures of these specimens, it is possible that the microorganisms found in the smears may have been killed by the antibacterial activity of the inflammatory reaction or they may have been below the minimum inoculum level required to initiate growth. The microbial isolates obtained from the 118 culture specimens were found either singly or in mixtures of two or more species. Fifty-two of 118 cultures arrived at the laboratory with cloudy or granular growth. The remaining sixtysix gave evidence of growth after 2 to 8 days’ incubation. The results are tabulated in Table III. The majority of the cultures (75.4 per cent) contained two or more microbial species. The various species isolated are listed in Table IV. Members of the streptococcus family were found most frequently, with the mitis and salivarius species predominating. The beta hemolytic streptococcus was isolated in only two (1.7 per cent) of the 135 streptococeal isolates. The relative frequency of the various streptococcal species isolated is also given in Table IV. In addition to the alpha streptococci, the more frequent isolates were Staphylococcus aureus, the lactobacilli, the coliform bacilli, and the diphtheroids. The comparative relationships of the isolates to each other are also given in Table IV. There are several possible reasons why microorganisms observed in smears were not isolated from cultures : 1. Numbers of the bacilli were very small in comparison to the number of cocci present in smears and were overgrown. 2’. Inoculum contained too few microorganisms to initiate growth. 3. Inflammatory reaction of pulp or periapical fluid may have killed microTable
III. Number of microbial species isolated
Number of isolates Number of specimens Per cent Total Total
cultures: 118 mixed cultures:
1 29 24.5 75.4 per cent
250
Barteb,
Naidorf,
and Blechman
O.S., OX & O.P. February, 1968
Table IV. Species isolated Streptococci str. ?nitis SW. salivarizls Gamma Enterococcus Beta hemolytic Anaerobic Total
58 (42.9%) 55 (40.8%) ‘5” i’q 2 ( 1:4& 1 ( 0.7%) 135 (99.9%)
streptococci
Other spe&es 32 4 4 15 31
Staphylococcus Large micrococcus Neisseria Coliforms Lactobacillus Diphtheroids Bacteroides nigrescens (melcdnogenicus) Baoteroides (species not determined) Pseudomonas aerzlginosa Can&da albicans Can&da tropiealis Actinomyces Nocardia Saw&a lutea Bacillus subtilis
Y 4 2 5 : 2 1 6 118 253
Total other species Grand total of isolates Streptooocd
in relation to
isolated
71.80/o 53.4% 87.1%
Total specimens Total isolates Other species isolates Staphylococcus
aurew
isolated
in relation
Laotobacilli
kolated
in relation
to 17.0% 12.2% 23.4% 27.0%
Total specimens Total isolates Total streptococci Other species isolates Col&forms
isolated
in relation
to
8.5%
Total specimens Total isolates Total streptococci Other species isolates Diphtheroids
isolated
in relation
Total specimens Total isolates Total streptococci Other species isolates
to 17.0% 12.6% 23.7% 27.1%
Total specimens Total isolates Total streptococci Other species isolates
5.9% 11.7% 13.5% to
4.6% 3.5% 6.6% 7.6%
Volume 25 Number 2
Factors
associated with
Table V. Comparison of microorganisms A. Total cultures with growth Smear and culture isolates
“flare-ups”
endodontic
in smear and culture 118 96 (81.35%)
agree
B. Microorganisms present in smears but not isolated from Some smears had more than one type of microorganism Gram-positive bacilli in smears only Gram-negative bacilli in smears only Gram-positive and gram-negative bacilli in smears
22 (18.65%)
cultures
6 ( 5.09%) 9 ( 7.63%) 7 ( 5.93%) 22 (18.65%')
only Total
C. Microorganisms isolated Neisseria species Coliform Lactobacillus B. mbtilis Candida albicans Candida tropicalis
from
Table VI. Apical penetration
cultures
and not observed
; ( 7.6 010)
and bacterial growth (
Number
Total I. Apex penetrated (0.5 to 4 mm.) Growth of microorganisms No growth of microorganisms Total No apical penetration Growth of microorganisms No growth of microorganisms
of case8
Apical penetration9 Not answered on questionnaire Growth of microorganisms No growth of microorganisms Total
1
Per oent
53 73 31
33.7 46.4 19.9
157
100.0
39 14
73.7 26.3
53
100.0
50 23 Total
III.
in smears
1 1 2 2 1
Apical penetration No apical penetration Not answered on questionnaire
II.
259
$3
68.3 31.7 100.0
21 10
67.7 32.3
31
100.0
organisms. (The presence of microorganisms in a smear is no indication of viability.) 4. Improper media for isolation. 5. Gram-negative bacilli associated with the gram-positive bacilli in ,smears may be dead organisms of the gram-positive species. Dead gram-positive microorganisms frequently show a gram-negative stain reaction. In 126 “flare-up” cases, the questionnaires contained data relative to penetration or nonpenetration of the apex. Although fifty-three apical penetrations were reported, it appears from the foregoing data that there was no significant relationship between apical penetration and microbiologic findings. It should be remembered that this was an uncontrolled st,udy in that no data were obtained as to how frequently apical penetrations are unassociated with “flare-ups.”
260
Bartels,
SUMMARY
Naidorf,
a8nd Blechman
O.S., O.M. & O.P. February, 1968
AND CONCLUSIONS
The results of this study may be construed as being somewhat biased, since the 196 “flare-ups” occurred in the practices of twenty-six endodontists and since four fifths (80 per cent) of the specimens were submitted by only sixteen dentists. The results obtained from the data given in the questionnaires and the microbiologic examinations have led to the following conclusions : 1. Cultures should be incubated more than the customary 48 hours, preferably 1 week, before they are discarded as showing no growth of microorganisms. 2. Microorganisms with similar morphologic and staining characteristics were found in both the smear and the culture in ninety-six of 118 specimens (81.3 per cent). These data included the specimens which contained one or more microbial species. 3. Mixed microbial species were found in eighty-nine (75.4 per cent) of the 118 cultures examined. Two isolates were obtained in fifty-two specimens (45 per cent) ; three in thirty-three specimens (27 per cent), and four in four specimens (3.4 per cent). 4. The predominant microorganism isolated was the Xtreptococcus mitti, with the Streptococcus salivarius a close second. 5. Microorganisms observed in smears were not isolated from cultures in twenty-two instances (18.7 per cent). These microorganisms were primarily bacilli-gram-positive, gram-negative, or both. Nonisolation possibly was due to (a) a root canal inoculum which contained too few microorganisms to initiate growth, (b) death of the microorganisms as a result of metabolic products of the predominant streptococci present in some of the specimens, or (c) the antibacterial activity of the inflammatory reaction. It is interesting to note that Burnett and Scherp’ state that if throat swabs contain fewer than 1,000 pathogenic streptococci, growbh does not always occur after plating on solid media. 6. Isolates obtained from nine cultures were not observed in smears of the root canal specimens. These may have been due to contamination or to their relative infrequency in smears. 7. No relationship w-as noted between symptoms (time of occurrence, swelling, or pain) and any specific isolates. 8. Specimens were submitted from fifty-three casesof apical penetration and from seventy-three cases of “no apical penetration,” Microorganisms were isolated from 5 per cent more of the apical penetration cases. This result, however, is not significant, since the study was uncontrolled as to number of specimens in each category and since precise determination of apical penetration was not always followed. 9. The examination of smears may give significant results with respect to the intensity of the inflammatory reaction as determined by the number of polymorphonuclear leukocytes present. Frequently such a response is accompanied by the presence of relatively few microorganisms. This, we believe, is an indication of the efficiency of the inflammatory reaction in destroying microorganisms.
Vdume 25 Number 2
Pactors associated with
endodontic
“flare-ups”
261
On the other hand, the presence of lactobacilli and, in a few instances, of quamous epithelial cells may be interpreted as evidence of salivary contamination. Likewise, the presence of numerous microorganisms and the absence of leukocytes may also be considered as suggestive of contamination by microorganisms from the saliva. We believe, therefore, that the smear is an important adjunct in evaluating the progress of endodontic therapy. REFERENCE
1. Burnett, G. W., and Scherp, H. W.: Oral Microbiology Baltimore, 1962, Williams C Wilkins Company, p. 583.
and Infectious
Disease,
ed. 2:
OF MICROBIOLOGY,
UNIVERSITY,
AND
DEPARTMENT
DENTAL
ORAL
SURGERY,
AND
COLLEGE
OF DENTlSTRY,
OF RESTORATIVE COLUMBIA
NFJV
DEXTISTRY,
YORK
SCHOOL
OF
UTIVERSITY
A
study was undertaken by the T&State Society of Endodontism to determine the causative factors of Wflare-ups” which occur during endodontic therapy. A “flare-up” was defined as a condition of pain or swelling resulting in an emergency (nonroutine or nonscheduled) visit. Smears and cultures from such cases, together with a questionnaire, were forwarded to the Department of Microbiology, College of Dentistry, New York University, for examination. From the data submitted, detailed information was obtained relative to the tooth involved, previous history of duration and degree of pain, apical penetration during instrumentation, periodontal lesions, and type of treatment and medication. An x-ray film was also submitted for examination. The study included 196 specimens, and the conclusions and tabulations presented here reflect the results of the bacteriologic examinations and the clinical dat,a submitted. Since the data were not always properly recorded by the participants in the study, a number of questionnaires were invalidated in one or more categories. For example, some cultures arrived with no histories or with incomplete data; others were broken during transit, as a result of improper packing; and in some instances x-ray films were not submitted. Thus, in the accompanying tables the total numbers of cases in various categories are not identical. *Associate Clinical Professor, Department of Microbiology, **Associate Clinical Professor, Department of Restorative tion, Columbia University. ***Acting Dean and Professor, Department of Microbiology,
New York University. Dentistry, Endodontie New
Pork
Pec-
IJniversity.
255
03, ox & 02. Fehruar~, 1968
MATERIALS AND METHODS
Each dentist was supplied with kits consisting of a qucstionnairc, a glass slide on which exudate or transudate from the canal was to be smeared, and a screw-capped tube containing trypticase soy broth with 0.1 per cent agar for cuburing. The smear and culture were securely wrapped, placed in a standard mailing carton, and forwarded by first class mail. The smear was stained by Gram’s method and examined for microorganisms and the presence of leukocytes. If no growth occurred, the cultures were incubated at least 10 days before being discarded. When growth occurred in the broth, subcultures were made to appropriate media for isolation and identification of the isolates. RESULTS
The data obtained from a study of the questionnaires submitted and the results of the microbiologic examinations are given in the accompanying tables. Only twenty-six of the 125 endodontists with membership in the Society submitted specimens, and of the 196 specimens submitted, four fifths (161) were forwarded by sixteen members. Thirty-one of the specimens were invalidated as a result of being broken in transit or because smears were submitted without cultures. Of the remaining 165 cultures, 141 (85 per cent) were received within 4 days, so that extended delay in transit was not a factor in the retardation of growth. In the remaining 15 per cent of the specimens, however, delays of 7 days to 3 weeks occurred, as most of the specimens were mailed during the holiday season. Among the 113 cultures which arrived at the laboratory without any apparent growth, a uniform turbidity or granular growth developed within an incubation period of 48 hours in sixty-two (55 per cent), after 4 days of incubation in two, and after 8 days of incubation in two. The remaining forty-seven cultures were maintained at 37O C. incubation for a minimum of 10 days before being discarded and reported as “NO growth of microorganisms occurred.” Table 1.Appearance of culture on arrival Clear (no observable Cloudy (growth)
113 specimens 52 specimens
growth) Total
5%
II. Microscopic examination of smears submitted with the “no growth” cultures
Table
Polymorphmuclear leukocytes None Few Moderate Many Totals
Nicroorganimns Specimens
None
4 6
2 4 ;
5 9 -iG
1
Few 1
i
present
in smears
) Moderate
1
&fany
1 0 :
0 0
0
7 a
-z-
0 -i-
0
Volume 25 Number 2
Factors associated with emiodontic “flare-ups”
257
The forty-seven cultures which gave no evidence of growth during a minimum 10 day period of incubation were found in thirty-four instances (72.3 per cent) to have been in transit 4 days or less. The “no growth” specimens were studied further to determine whether the smear preparations accompanying them would afford any significant data in relation to microorganisms and the inflammatory reaction. Unfortunately, smears were not forwarded in ten instances, whereas in another twelve cases t,he smears contained insufficient material, and one slide was broken in transit,. Apparently, in eight of the twenty-four specimens no microorganisms were seen. A few organisms were found in thirteen of the smears, and in only three were a moderate number present. The number of polymorphonuclear leukocytes varied from none to many. Many leukocytes were present in nine smears, but in seven of these only a few microorganisms were observed. In one of the remaining two smears no organisms were found, while in the other a moderate number were observed. Since no growth was obtained in cultures of these specimens, it is possible that the microorganisms found in the smears may have been killed by the antibacterial activity of the inflammatory reaction or they may have been below the minimum inoculum level required to initiate growth. The microbial isolates obtained from the 118 culture specimens were found either singly or in mixtures of two or more species. Fifty-two of 118 cultures arrived at the laboratory with cloudy or granular growth. The remaining sixtysix gave evidence of growth after 2 to 8 days’ incubation. The results are tabulated in Table III. The majority of the cultures (75.4 per cent) contained two or more microbial species. The various species isolated are listed in Table IV. Members of the streptococcus family were found most frequently, with the mitis and salivarius species predominating. The beta hemolytic streptococcus was isolated in only two (1.7 per cent) of the 135 streptococeal isolates. The relative frequency of the various streptococcal species isolated is also given in Table IV. In addition to the alpha streptococci, the more frequent isolates were Staphylococcus aureus, the lactobacilli, the coliform bacilli, and the diphtheroids. The comparative relationships of the isolates to each other are also given in Table IV. There are several possible reasons why microorganisms observed in smears were not isolated from cultures : 1. Numbers of the bacilli were very small in comparison to the number of cocci present in smears and were overgrown. 2’. Inoculum contained too few microorganisms to initiate growth. 3. Inflammatory reaction of pulp or periapical fluid may have killed microTable
III. Number of microbial species isolated
Number of isolates Number of specimens Per cent Total Total
cultures: 118 mixed cultures:
1 29 24.5 75.4 per cent
250
Barteb,
Naidorf,
and Blechman
O.S., OX & O.P. February, 1968
Table IV. Species isolated Streptococci str. ?nitis SW. salivarizls Gamma Enterococcus Beta hemolytic Anaerobic Total
58 (42.9%) 55 (40.8%) ‘5” i’q 2 ( 1:4& 1 ( 0.7%) 135 (99.9%)
streptococci
Other spe&es 32 4 4 15 31
Staphylococcus Large micrococcus Neisseria Coliforms Lactobacillus Diphtheroids Bacteroides nigrescens (melcdnogenicus) Baoteroides (species not determined) Pseudomonas aerzlginosa Can&da albicans Can&da tropiealis Actinomyces Nocardia Saw&a lutea Bacillus subtilis
Y 4 2 5 : 2 1 6 118 253
Total other species Grand total of isolates Streptooocd
in relation to
isolated
71.80/o 53.4% 87.1%
Total specimens Total isolates Other species isolates Staphylococcus
aurew
isolated
in relation
Laotobacilli
kolated
in relation
to 17.0% 12.2% 23.4% 27.0%
Total specimens Total isolates Total streptococci Other species isolates Col&forms
isolated
in relation
to
8.5%
Total specimens Total isolates Total streptococci Other species isolates Diphtheroids
isolated
in relation
Total specimens Total isolates Total streptococci Other species isolates
to 17.0% 12.6% 23.7% 27.1%
Total specimens Total isolates Total streptococci Other species isolates
5.9% 11.7% 13.5% to
4.6% 3.5% 6.6% 7.6%
Volume 25 Number 2
Factors
associated with
Table V. Comparison of microorganisms A. Total cultures with growth Smear and culture isolates
“flare-ups”
endodontic
in smear and culture 118 96 (81.35%)
agree
B. Microorganisms present in smears but not isolated from Some smears had more than one type of microorganism Gram-positive bacilli in smears only Gram-negative bacilli in smears only Gram-positive and gram-negative bacilli in smears
22 (18.65%)
cultures
6 ( 5.09%) 9 ( 7.63%) 7 ( 5.93%) 22 (18.65%')
only Total
C. Microorganisms isolated Neisseria species Coliform Lactobacillus B. mbtilis Candida albicans Candida tropicalis
from
Table VI. Apical penetration
cultures
and not observed
; ( 7.6 010)
and bacterial growth (
Number
Total I. Apex penetrated (0.5 to 4 mm.) Growth of microorganisms No growth of microorganisms Total No apical penetration Growth of microorganisms No growth of microorganisms
of case8
Apical penetration9 Not answered on questionnaire Growth of microorganisms No growth of microorganisms Total
1
Per oent
53 73 31
33.7 46.4 19.9
157
100.0
39 14
73.7 26.3
53
100.0
50 23 Total
III.
in smears
1 1 2 2 1
Apical penetration No apical penetration Not answered on questionnaire
II.
259
$3
68.3 31.7 100.0
21 10
67.7 32.3
31
100.0
organisms. (The presence of microorganisms in a smear is no indication of viability.) 4. Improper media for isolation. 5. Gram-negative bacilli associated with the gram-positive bacilli in ,smears may be dead organisms of the gram-positive species. Dead gram-positive microorganisms frequently show a gram-negative stain reaction. In 126 “flare-up” cases, the questionnaires contained data relative to penetration or nonpenetration of the apex. Although fifty-three apical penetrations were reported, it appears from the foregoing data that there was no significant relationship between apical penetration and microbiologic findings. It should be remembered that this was an uncontrolled st,udy in that no data were obtained as to how frequently apical penetrations are unassociated with “flare-ups.”
260
Bartels,
SUMMARY
Naidorf,
a8nd Blechman
O.S., O.M. & O.P. February, 1968
AND CONCLUSIONS
The results of this study may be construed as being somewhat biased, since the 196 “flare-ups” occurred in the practices of twenty-six endodontists and since four fifths (80 per cent) of the specimens were submitted by only sixteen dentists. The results obtained from the data given in the questionnaires and the microbiologic examinations have led to the following conclusions : 1. Cultures should be incubated more than the customary 48 hours, preferably 1 week, before they are discarded as showing no growth of microorganisms. 2. Microorganisms with similar morphologic and staining characteristics were found in both the smear and the culture in ninety-six of 118 specimens (81.3 per cent). These data included the specimens which contained one or more microbial species. 3. Mixed microbial species were found in eighty-nine (75.4 per cent) of the 118 cultures examined. Two isolates were obtained in fifty-two specimens (45 per cent) ; three in thirty-three specimens (27 per cent), and four in four specimens (3.4 per cent). 4. The predominant microorganism isolated was the Xtreptococcus mitti, with the Streptococcus salivarius a close second. 5. Microorganisms observed in smears were not isolated from cultures in twenty-two instances (18.7 per cent). These microorganisms were primarily bacilli-gram-positive, gram-negative, or both. Nonisolation possibly was due to (a) a root canal inoculum which contained too few microorganisms to initiate growth, (b) death of the microorganisms as a result of metabolic products of the predominant streptococci present in some of the specimens, or (c) the antibacterial activity of the inflammatory reaction. It is interesting to note that Burnett and Scherp’ state that if throat swabs contain fewer than 1,000 pathogenic streptococci, growbh does not always occur after plating on solid media. 6. Isolates obtained from nine cultures were not observed in smears of the root canal specimens. These may have been due to contamination or to their relative infrequency in smears. 7. No relationship w-as noted between symptoms (time of occurrence, swelling, or pain) and any specific isolates. 8. Specimens were submitted from fifty-three casesof apical penetration and from seventy-three cases of “no apical penetration,” Microorganisms were isolated from 5 per cent more of the apical penetration cases. This result, however, is not significant, since the study was uncontrolled as to number of specimens in each category and since precise determination of apical penetration was not always followed. 9. The examination of smears may give significant results with respect to the intensity of the inflammatory reaction as determined by the number of polymorphonuclear leukocytes present. Frequently such a response is accompanied by the presence of relatively few microorganisms. This, we believe, is an indication of the efficiency of the inflammatory reaction in destroying microorganisms.
Vdume 25 Number 2
Pactors associated with
endodontic
“flare-ups”
261
On the other hand, the presence of lactobacilli and, in a few instances, of quamous epithelial cells may be interpreted as evidence of salivary contamination. Likewise, the presence of numerous microorganisms and the absence of leukocytes may also be considered as suggestive of contamination by microorganisms from the saliva. We believe, therefore, that the smear is an important adjunct in evaluating the progress of endodontic therapy. REFERENCE
1. Burnett, G. W., and Scherp, H. W.: Oral Microbiology Baltimore, 1962, Williams C Wilkins Company, p. 583.
and Infectious
Disease,
ed. 2: