Scand..J. Dent. Res. 1978: 86: 366-373 (Kcv words: pulp diseases: pulpedomy: root canal therapy)
Clinical and radiographic study of pulpectomy and root canal therapy M. A. JOKINEN, RISTO KOTILAINEN, PEKKA POIKKEUS, RAIJA POIKKEUS AND LEENA SARKKI Institute of Dentistry, University of Helsinki, Helsinki, Finland
ABSTRACT - A clinical and radiogi-aphic reexamination of 2,459 roots 2—7 years after initial pulpectomy or root canal therapy is presented. The overall success rate, which was 53%, was not affected by the sex or age of the patient, or by the jaw in which the tooth was situated. Tlie tooth group, however, had a significant influence on the success rate, the worst results being obtained for incisors and especially the mandibular central and maxillary lateral incisors. The prognosis was clearly better for the pulpectomies than for the root canal therapy. Mortal pulpectomy was found to succeed more often than vital. The presence of a primary periapical rarefaction worsened the success rate. The success rate was lower for the teeth in which a posttreatment prosthetic crown had been fitted. Fillings which went beyond the apex had a significantly lower success rate than those which nearly or exactly readied the apex. (Accepted for publication 21 May 1978)
The criteria for recognition of successful pulpectomy and root canal therapy are illdefined. The evaluation is usually based on a periapical radiograph and the clinical signs and symptoms, though histologic or bacteriologic studies have been reported, albeit rarely. The combined reports of histologic and radiographic findings, however, have shown a good correlation between these two methods of evaluating periapical disease (ENGEL 1950, WENGRAF 1965, BRYNOLF 1967). The interpretation of the radiographs has varied between studies. Thus a normal periapical region at a defined time after therapy has been the criterion of success in some studies while partial healing of a prior rarefaction was sufficient in others.
Further, the "complete healing" in some reports tolerates a radiolucent area around excess filling (STRINDBERG 1956, GRAHNEN & HANSSON 1961). If the criterion of success is complete osseous regeneration, success rates fall to 39-6296 (BENDER, SELTZER & SOLTANOFF 1966). The postoperative observation time has also varied in different investigations from 6 months to 18 years. NICHOLLS (1961), in a review of the literature, concluded that, as a general rule, a 2-year period may be considered adequate. SELTZER, BENDER, SMITH, FREEDMAN & NAZIMOV(1967) also pointed out that though failure might be observed even 10 years after operation, the vast majority of unsuccessful cases were noticed within 2 years of treatment.
PULPECTOMY AND ROOT CANAL THERAPY
(1956), on the other hand, claimed that a 4-year observation period was needed. The age and sex of the patient are not usually considered to affect the success rate, while the initial periapical rarefaction and overfilling are generally thought to reduce the percentage of successes STRINDBERG
(HOLST
1941,
CASTAGNOLA
STRINDBERG 1956,
1950,
GRAHNEN & HANSSON
1961, SELTZER et al. 1967). Several investigations have shown that the tooth group affects the success rate, with the worst results for incisors (GoOD 1943, FECHTER
1955,
STRINDBERG
GRAHNEN ^ HANSSON 1961, LUNDBERG
1965,
MALMCRONA 8C MILTHON
1956,
ENGSTROM & BERGENHOLTZ,
1973).
Material and methods This study includes all patients subjected to pulpectomy and root canal therapy at the Department of Endodontics, Institute of Dentistry, University of Helsinki, in the years 1964-69. Eor each patient the following data were recorded: age and sex, diagnosis of the treated tooth, medication, type of treatment, periapical condition and the subsequent restorative treatment. The treatments were carried out by students under the supervision oi teachers. When the pulp was vital, it was extirpated under local anesthesia or after devitalization with a paraformaldehyde paste. The root canals were cleansed mechanically with reamers and files, and Decal*, an organic acid, was used to irrigate the root canal. Teeth with necrotic or gangrenous pulp were root filled after mechanical and chemical irrigation (hydrogen peroxide 5% and Decal). The canals were medicated with a chemotherapeutic corticosteroid preparation Triodent* (dexamethasone sodium phosphate, dequalone acetate, 5+10 mg/ml), except in 317 cases which were treated with the same preparation without the corticosteroid. When acute
367
periapical osteitis was diagnosed, systemic antibiotic therapy, usually penicillin, was used. The canals were filled with chloropercha condensed with guttapercha points. Rubber dam protection was used when there was enough crown present. In about half of the cases, however, the treated tooth was isolated from saliva with cotton rolls. No bacteriologic tests were carried out on the root canal content. A preoperative radiograph was always taken and, if necessary, a second radiograph was taken with a reamer inserted into the root canal in order to calculate its length. A postoperative radiograph was taken in order to assess the quality of the filling. Only dense fillings were accepted. Patients were recalled for examination in the period 1968—76. The clinical evaluation included the following: subjective symptoms, sensitivity to percussion, evidence ^of fistula, presence of swelling. A stereoradiograph was taken in all cases and reported separately by two investigators (M.A.J. and R.K.). When opinions differed, the cases were reexamined together. The whole material treated during the period 1964-69 and the reexamined material finally used in the analysis are shown in Table 1. Throughout, rates are given per root. The reasons for exclusion are shown in Table 2. These cases have not been interpreted as unconditionally unsuccessful because in none of them could it be proved that the reason for extraction had been the failure of the endodontic treatment. In this investigation overfilling and underfilling means fillings that go more than 0.5 mm beyond or end more than 0.5 mm before the radiographic apex of the root. The criteria for success were: (1) a radiographically healthy periapical bone structure, periodontal membrane and continuous lamina dura and (2) absence of symptoms. Cases in which the area of an initial rarefaction had definitely become smaller, but in which bone repair was incomplete, were classified as "doubtful". An unsuccessful case was one in which an area of rarefaction had developed where none was present initially, or in which an initial area of rarefaction had persisted or become larger, or in which the tooth showed symptoms. In statistical analyses the chi-square method was used.
368
JOKINEN ET AL. Table 1 Material ofthe investigation
Excluded for various reasons (Table 2)
Did not respond to several recalls
Entire material
Patients 2,592 Teeth Roots
Final material
n
%
n
%
n
1,272
49
121 261
4.7
1,199 1,782 2,459
96 45.8
Table 2 Reasons for the exclusion of 261 teeth
Unsatisfactory radiographs Extraction of teeth for prosthetic reasons Extraction of teeth because of detached filling, new carious lesions or acute symptoms in the area Extraction of tooth for unknown reasons
93 55
Total
261
Results The results obtained in the clinical and radiographic reexamination of the pulpectomies and root canal therapy are presented in Tables 3-6. Where a certain group contained a significantly high proportion of incisors, overfilled roots or cases with initial rarefaction, all of which have been found to afFect the results adversely, a supplementary analysis was made by excluding such cases from that group. O^ the total material 1,304 procedures (53 96) were successful, 314 (13%) doubtful and 841 (34%) failures. Jaw — The success ratios for the mandible and the maxilla were very similar (F>0.03, Table 3). Tooth group — There were marked differences between the success rates for the different tooth groups and for
40 73
different teeth. The success rate was much lower for the incisors than for the other groups of teeth, and was especially low for the mandibular first and maxillary second incisors (Table 3). Sex and age - The sex and age of the patient had only a small effect upon the success rate (Table 4) (P> 0.05). Observation time - In root canal therapy the success rate was low during the first 3 years after treatment. Subsequently the rate was steady except for the 7-year observation period, when the results were better than average. In the pulpectomy series the success rate was consistently above 60% except for the period 4 years after therapy (Table 6). Diagnosis and type of treatment -
The
prognosis was better if the pulp had been vital before treatment and mortal pulpectomy was found to succeed more often than vital (Table 4).
PULPECTOMY AND ROOT CANAL THERAPY
369
Table 3 Results ofpulpectomies and root canal therapy in different jaws and tooth groups
Successful
Doubtful
Mandible First incisors Second incisors Canines First premolars Second premolars First molars Second molars Third molars
595 11 18 45 47 91 198 162 23
55 22 35 48 57 62 53 66 79
127 7 7 13 9 16 43 28 4
12 14 14 14 11 11 11 11 14
355 32 26 35 27 40 136 57 2
33 64 51 38 32 27 36 23 7
1,077 50 51 93 83 147 377 247 29
44 2 2 4 3 6 15 10 1
Maxilla First incisors Second incisors Canines First premolars Second premolars First molars Second molars
709 81 49 74 78 93 233 101
51 40 26 49 44 64 64 66
187 37 38 22 35 8 35 12
14 18 20 15 20 6 10 8
486 84 104 54 64 44 95 41
35 42 54 36 36 30 26 26
1,382 202 191 150 177 145 363 154
56 8 8 6 7 6 15 6
Failures
Total
Table 4 Results of pulpectomies and root canal therapy grouped according to sex, age, diagnosis or treatment method and the presence of an initial rarefaction
Successful
Doubtful
Total n
n
%
n
%
n
%
Female
825
53
215
14
523
33
1,563
64
Male
479
54
99
11
318
35
896
36
16-29 years 30-49 years 50—75 years
605 480 219
52 54 53
147 107 60
13 12 14
407 298 136
35 34 33
1,159 885 415
47 36 17
Vital extirpation Mortal extirpation Necrosis pulpae Chronic osteitis Acute osteitis
441 270 227 135 231
54 66 67 36 44
76 31 36 73 98
CTl
Failures
8 11 20 18
296 107 74 165 199
37 26 22 44 38
813 408 337 373 528
33 17 14 15 21
Without initial rarefaction With rarefaction
984 320
61 38
146 168
9 20
488 353
30 42
1,618
66 34
%
370
JOKINEN ET AL. Table 5
Results of pulpectomies and root canal therapy grouped according to medication, preparation of a prosthetic crown after the treatment and the type of filling Successful
Doubtful
Failures
Total
n Corticosteroid medication Witiioui corticosteroid
1,159
54
276
13
707
33
2,142
87
145
46
38
12
134
42
317
13
Prosthetic crown Without prosthetic crown
345
46
106
14
297
40
748
30
959
56
208
12
544
32
1,711
70
Uiulcrfilled Filled to the apex Ovcrlillcd
461 338 505
70 57 42
40 63 211
6 11 17
159 187 495
24 32 41
660 588 1,21!
27 24 49
Table 6 Resulls of pulpectorniei and root canal therapy according to the length of the period of observation Duration of ol)seryation period
Successful
Doubtful
Failures
Total
n
96
n
96
n
%
n
Pulpeclomies 2-3 vcars 4 yea IS 5 vcars 6 N'cars 7 vcars
10 126 172 291 112
66 46 60 62 65
1 21 23 49 13
7 8 8 10 7
4 128 91 132 48
27 46 32 28 28
15 275 286 472 173
Total
711
58
107
9
403
33
1,221
Root canal therapy 2—3 years 4 years 5 years 5 years 7 vears
6 90 124 279 94
25 48 45 47 61
8 26 42 111 20
S3 14 15 18 13
10 71 108 208 41
42 38 40 35 26
24 187 274 598 155
Total
593
48
207
17
438
35
1,238
PULPECTOMY AND ROOT CANAL THERAPY When all incisors and overfilled roots were excluded from the material, the success rate for vital extirpation was 6496 and for mortal extirpation 7596. Both chronic and acute osteitis cases had a success rate of 5896. When grouped by diagnosis and type of treatment there were statistically significant differences {PKO.OOD. Initial periapical
rarefaction
—
The
presence of a primary periapical rarefaction lowered the success rate significantly (/'< 0.001, Table 4). When all incisors were excluded, the success rate for cases without initial rarefaction was 6596 and with rarefaction 4396. When all overfilled roots were excluded, the success rates were 7196 and 5596 respectively. These differences were statistically significant
371
the success rates were: filled short of the apex, 7296; filled to the apex, 6296; overfilled, 47 96. When the cases with initial rarefaction were also excluded, the respective success rates were 7596, 6596 and 5596. These differences were statistically significant (P
Clinical and radiographic study of pulpectomy and root canal therapy M. A. JOKINEN, RISTO KOTILAINEN, PEKKA POIKKEUS, RAIJA POIKKEUS AND LEENA SARKKI Institute of Dentistry, University of Helsinki, Helsinki, Finland
ABSTRACT - A clinical and radiogi-aphic reexamination of 2,459 roots 2—7 years after initial pulpectomy or root canal therapy is presented. The overall success rate, which was 53%, was not affected by the sex or age of the patient, or by the jaw in which the tooth was situated. Tlie tooth group, however, had a significant influence on the success rate, the worst results being obtained for incisors and especially the mandibular central and maxillary lateral incisors. The prognosis was clearly better for the pulpectomies than for the root canal therapy. Mortal pulpectomy was found to succeed more often than vital. The presence of a primary periapical rarefaction worsened the success rate. The success rate was lower for the teeth in which a posttreatment prosthetic crown had been fitted. Fillings which went beyond the apex had a significantly lower success rate than those which nearly or exactly readied the apex. (Accepted for publication 21 May 1978)
The criteria for recognition of successful pulpectomy and root canal therapy are illdefined. The evaluation is usually based on a periapical radiograph and the clinical signs and symptoms, though histologic or bacteriologic studies have been reported, albeit rarely. The combined reports of histologic and radiographic findings, however, have shown a good correlation between these two methods of evaluating periapical disease (ENGEL 1950, WENGRAF 1965, BRYNOLF 1967). The interpretation of the radiographs has varied between studies. Thus a normal periapical region at a defined time after therapy has been the criterion of success in some studies while partial healing of a prior rarefaction was sufficient in others.
Further, the "complete healing" in some reports tolerates a radiolucent area around excess filling (STRINDBERG 1956, GRAHNEN & HANSSON 1961). If the criterion of success is complete osseous regeneration, success rates fall to 39-6296 (BENDER, SELTZER & SOLTANOFF 1966). The postoperative observation time has also varied in different investigations from 6 months to 18 years. NICHOLLS (1961), in a review of the literature, concluded that, as a general rule, a 2-year period may be considered adequate. SELTZER, BENDER, SMITH, FREEDMAN & NAZIMOV(1967) also pointed out that though failure might be observed even 10 years after operation, the vast majority of unsuccessful cases were noticed within 2 years of treatment.
PULPECTOMY AND ROOT CANAL THERAPY
(1956), on the other hand, claimed that a 4-year observation period was needed. The age and sex of the patient are not usually considered to affect the success rate, while the initial periapical rarefaction and overfilling are generally thought to reduce the percentage of successes STRINDBERG
(HOLST
1941,
CASTAGNOLA
STRINDBERG 1956,
1950,
GRAHNEN & HANSSON
1961, SELTZER et al. 1967). Several investigations have shown that the tooth group affects the success rate, with the worst results for incisors (GoOD 1943, FECHTER
1955,
STRINDBERG
GRAHNEN ^ HANSSON 1961, LUNDBERG
1965,
MALMCRONA 8C MILTHON
1956,
ENGSTROM & BERGENHOLTZ,
1973).
Material and methods This study includes all patients subjected to pulpectomy and root canal therapy at the Department of Endodontics, Institute of Dentistry, University of Helsinki, in the years 1964-69. Eor each patient the following data were recorded: age and sex, diagnosis of the treated tooth, medication, type of treatment, periapical condition and the subsequent restorative treatment. The treatments were carried out by students under the supervision oi teachers. When the pulp was vital, it was extirpated under local anesthesia or after devitalization with a paraformaldehyde paste. The root canals were cleansed mechanically with reamers and files, and Decal*, an organic acid, was used to irrigate the root canal. Teeth with necrotic or gangrenous pulp were root filled after mechanical and chemical irrigation (hydrogen peroxide 5% and Decal). The canals were medicated with a chemotherapeutic corticosteroid preparation Triodent* (dexamethasone sodium phosphate, dequalone acetate, 5+10 mg/ml), except in 317 cases which were treated with the same preparation without the corticosteroid. When acute
367
periapical osteitis was diagnosed, systemic antibiotic therapy, usually penicillin, was used. The canals were filled with chloropercha condensed with guttapercha points. Rubber dam protection was used when there was enough crown present. In about half of the cases, however, the treated tooth was isolated from saliva with cotton rolls. No bacteriologic tests were carried out on the root canal content. A preoperative radiograph was always taken and, if necessary, a second radiograph was taken with a reamer inserted into the root canal in order to calculate its length. A postoperative radiograph was taken in order to assess the quality of the filling. Only dense fillings were accepted. Patients were recalled for examination in the period 1968—76. The clinical evaluation included the following: subjective symptoms, sensitivity to percussion, evidence ^of fistula, presence of swelling. A stereoradiograph was taken in all cases and reported separately by two investigators (M.A.J. and R.K.). When opinions differed, the cases were reexamined together. The whole material treated during the period 1964-69 and the reexamined material finally used in the analysis are shown in Table 1. Throughout, rates are given per root. The reasons for exclusion are shown in Table 2. These cases have not been interpreted as unconditionally unsuccessful because in none of them could it be proved that the reason for extraction had been the failure of the endodontic treatment. In this investigation overfilling and underfilling means fillings that go more than 0.5 mm beyond or end more than 0.5 mm before the radiographic apex of the root. The criteria for success were: (1) a radiographically healthy periapical bone structure, periodontal membrane and continuous lamina dura and (2) absence of symptoms. Cases in which the area of an initial rarefaction had definitely become smaller, but in which bone repair was incomplete, were classified as "doubtful". An unsuccessful case was one in which an area of rarefaction had developed where none was present initially, or in which an initial area of rarefaction had persisted or become larger, or in which the tooth showed symptoms. In statistical analyses the chi-square method was used.
368
JOKINEN ET AL. Table 1 Material ofthe investigation
Excluded for various reasons (Table 2)
Did not respond to several recalls
Entire material
Patients 2,592 Teeth Roots
Final material
n
%
n
%
n
1,272
49
121 261
4.7
1,199 1,782 2,459
96 45.8
Table 2 Reasons for the exclusion of 261 teeth
Unsatisfactory radiographs Extraction of teeth for prosthetic reasons Extraction of teeth because of detached filling, new carious lesions or acute symptoms in the area Extraction of tooth for unknown reasons
93 55
Total
261
Results The results obtained in the clinical and radiographic reexamination of the pulpectomies and root canal therapy are presented in Tables 3-6. Where a certain group contained a significantly high proportion of incisors, overfilled roots or cases with initial rarefaction, all of which have been found to afFect the results adversely, a supplementary analysis was made by excluding such cases from that group. O^ the total material 1,304 procedures (53 96) were successful, 314 (13%) doubtful and 841 (34%) failures. Jaw — The success ratios for the mandible and the maxilla were very similar (F>0.03, Table 3). Tooth group — There were marked differences between the success rates for the different tooth groups and for
40 73
different teeth. The success rate was much lower for the incisors than for the other groups of teeth, and was especially low for the mandibular first and maxillary second incisors (Table 3). Sex and age - The sex and age of the patient had only a small effect upon the success rate (Table 4) (P> 0.05). Observation time - In root canal therapy the success rate was low during the first 3 years after treatment. Subsequently the rate was steady except for the 7-year observation period, when the results were better than average. In the pulpectomy series the success rate was consistently above 60% except for the period 4 years after therapy (Table 6). Diagnosis and type of treatment -
The
prognosis was better if the pulp had been vital before treatment and mortal pulpectomy was found to succeed more often than vital (Table 4).
PULPECTOMY AND ROOT CANAL THERAPY
369
Table 3 Results ofpulpectomies and root canal therapy in different jaws and tooth groups
Successful
Doubtful
Mandible First incisors Second incisors Canines First premolars Second premolars First molars Second molars Third molars
595 11 18 45 47 91 198 162 23
55 22 35 48 57 62 53 66 79
127 7 7 13 9 16 43 28 4
12 14 14 14 11 11 11 11 14
355 32 26 35 27 40 136 57 2
33 64 51 38 32 27 36 23 7
1,077 50 51 93 83 147 377 247 29
44 2 2 4 3 6 15 10 1
Maxilla First incisors Second incisors Canines First premolars Second premolars First molars Second molars
709 81 49 74 78 93 233 101
51 40 26 49 44 64 64 66
187 37 38 22 35 8 35 12
14 18 20 15 20 6 10 8
486 84 104 54 64 44 95 41
35 42 54 36 36 30 26 26
1,382 202 191 150 177 145 363 154
56 8 8 6 7 6 15 6
Failures
Total
Table 4 Results of pulpectomies and root canal therapy grouped according to sex, age, diagnosis or treatment method and the presence of an initial rarefaction
Successful
Doubtful
Total n
n
%
n
%
n
%
Female
825
53
215
14
523
33
1,563
64
Male
479
54
99
11
318
35
896
36
16-29 years 30-49 years 50—75 years
605 480 219
52 54 53
147 107 60
13 12 14
407 298 136
35 34 33
1,159 885 415
47 36 17
Vital extirpation Mortal extirpation Necrosis pulpae Chronic osteitis Acute osteitis
441 270 227 135 231
54 66 67 36 44
76 31 36 73 98
CTl
Failures
8 11 20 18
296 107 74 165 199
37 26 22 44 38
813 408 337 373 528
33 17 14 15 21
Without initial rarefaction With rarefaction
984 320
61 38
146 168
9 20
488 353
30 42
1,618
66 34
%
370
JOKINEN ET AL. Table 5
Results of pulpectomies and root canal therapy grouped according to medication, preparation of a prosthetic crown after the treatment and the type of filling Successful
Doubtful
Failures
Total
n Corticosteroid medication Witiioui corticosteroid
1,159
54
276
13
707
33
2,142
87
145
46
38
12
134
42
317
13
Prosthetic crown Without prosthetic crown
345
46
106
14
297
40
748
30
959
56
208
12
544
32
1,711
70
Uiulcrfilled Filled to the apex Ovcrlillcd
461 338 505
70 57 42
40 63 211
6 11 17
159 187 495
24 32 41
660 588 1,21!
27 24 49
Table 6 Resulls of pulpectorniei and root canal therapy according to the length of the period of observation Duration of ol)seryation period
Successful
Doubtful
Failures
Total
n
96
n
96
n
%
n
Pulpeclomies 2-3 vcars 4 yea IS 5 vcars 6 N'cars 7 vcars
10 126 172 291 112
66 46 60 62 65
1 21 23 49 13
7 8 8 10 7
4 128 91 132 48
27 46 32 28 28
15 275 286 472 173
Total
711
58
107
9
403
33
1,221
Root canal therapy 2—3 years 4 years 5 years 5 years 7 vears
6 90 124 279 94
25 48 45 47 61
8 26 42 111 20
S3 14 15 18 13
10 71 108 208 41
42 38 40 35 26
24 187 274 598 155
Total
593
48
207
17
438
35
1,238
PULPECTOMY AND ROOT CANAL THERAPY When all incisors and overfilled roots were excluded from the material, the success rate for vital extirpation was 6496 and for mortal extirpation 7596. Both chronic and acute osteitis cases had a success rate of 5896. When grouped by diagnosis and type of treatment there were statistically significant differences {PKO.OOD. Initial periapical
rarefaction
—
The
presence of a primary periapical rarefaction lowered the success rate significantly (/'< 0.001, Table 4). When all incisors were excluded, the success rate for cases without initial rarefaction was 6596 and with rarefaction 4396. When all overfilled roots were excluded, the success rates were 7196 and 5596 respectively. These differences were statistically significant
371
the success rates were: filled short of the apex, 7296; filled to the apex, 6296; overfilled, 47 96. When the cases with initial rarefaction were also excluded, the respective success rates were 7596, 6596 and 5596. These differences were statistically significant (P
