Evaluation of Endodontic Treatment Failure of Teeth With Periapical Radiolucent
Areas and Factors Affecting It
S. Khedmat
Assistant Professor, Department of Endodontic, Faculty of Dentistry, Tehran University of Medical Science, Tehran, Iran
Statement of Problem: Failure of endodontic treatment is determined on the basis of radiographic findings and clinical signs and/ or symptoms of the treated teeth.
Purpose: The purpose of this study was to determine endodontic treatment failure in relation to various factors influencing it in teeth with periapical lesions (clinically and radiographically).
Materials and Methods: Teeth which had periapical lesions before treatment were selected from a series of teeth treated by endodontics’ postgraduate students over 5-year period (1997-2001) in Faculty of Dentistry Tehran university of Medical Science.
post operative follow up in 50 patients was possible .The patient’s ages ranged between 16 to 62 years old. 40 of patients were female and 10 were male. At the recall appointment, first the clinical information (pain, swelling, tenderness to palpation, percussion, …) were recorded in a questionnaire form, then two radiographies were obtained from each tooth.
The radiographies were assessed separately by three to five endodontists. Strindberg's criteria were used to Judge the failure of endodontic treatment. The observation period ranged from 1 to 5 years. The Data were analyzed statistically by using chi-square, Fisher’s exact test and MC Nemar test.
Results: Among different factors considered in this study, Fistula and sensation to percussion were reduced significantly (MC Nemar test, P=0.004). There were no significant difference between the extention of root canal filling, age and type of coronal restoration and endodontic failure which may be due to the small sample size of this study.
Conclusion: The rate of endodontic failure was 16%, which means 84% success rate, which is similar to results obtained from previous studies. The high success rate of endodontic treatment in teeth with periapical lesion may be explained by the fact that obturation has a definitive effect on reducing inflammation in periradicular area.
Key words: Periapical lesion; Failure; Endodontic treatment
Journal of Dentistry, Tehran University of Medical Sciences, Tehran, Iran (2004; Vol. 1, No. 2)
uccess or failure of endodotic treatment is determined on the basis of radiographic findings and clinical signs and/or symptoms of the treated teeth.
Normally the recall radiography is the main tool in evaluating success or failure of treatment.(1) Numerous studies have been published evaluating success and failure of endodontic
S
therapy various. Success rates from 40 to 96%
have been reported. The wide range of success rate might be because of differences in experimental design, clinical procedures, criteria for evaluating periapical healing, and the duration of the postoperative follow up.
One of the most important factors influencing the prognosis of endodontic treatment is the preoperative status of the teeth. Some investigators have suggested that the teeth with apical radiolucencies may have lower the success rate up to 20% than teeth without such lesions.(2) While other studies have demonstrated that prognosis of endodontic treatment in the teeth with periapical lesions are the same as teeth without any lesions if the instrumentation and filling of the root canal could be carried out to an optimal level.(3)
The purpose of this study was to determine failure rates in endodontically treated teeth with periapical lesions and the factors influencing it.
Strindberg’s criteria were used to evaluate the root canal therapy failure in endodontic postgraduate ward in Tehran University of Medical Science.(4)
Materials and Methods
This cross-sectional study accomplished on 153 teeth with preoperative periapical lesions. All teeth have been completed their endodontic treatment at least one year before they were selected for this study.
From 1600 teeth which have been endonontically treated by postgraduate students in endodontic department, only 153 teeth had inclusion criteria for present study.
All teeth have been prepared with hand instrumentation after rubber dam has been placed and were filled with gutta-percha and Zinc oxide eugenol as sealer using lateral condensation technique.
From 153 treated teeth with periapical radiolucency, only 50 patients came at the recall appointment.
Table I shows the various reasons for patients’
lack of cooperation.
The age of patients ranged from 16 to 62 years old. 40 of patients were female and 10 were male. At the recall examination, first the clinical information including pain, swelling, tenderness to palpation and percussion, periodontal disease, and type of coronal restoration were recorded in a questionnaire form. Then two radiographies with orthogonal and eccentric projection were obtained from each tooth.
In order to evaluate radiographic failure, the follow up radiographies were compared with previous radiographies of each tooth by three endodontists. In the case that of disagreement, the opinion of the fourth and the fifth endodontist were taken. Therefore, in each case, at least three endodontists had the same opinion.
Strindberg’s criteria were used to judge the treatment failure. These criteria are as follows:
- Persistence of Clinical signs and/or symptoms (pain, swelling, draining sinus tract, …)
- Development of draining sinus tract
- Increased, unchanged, or an appearance of new periradicular reinfection.
The follow up period ranged from 1 to 5 years.
The Data were analyzed statistically using chi-square, Fisher’s exact and Mc Nemar test.
The P-value less than 0.05 was assumed significant.
Table I- The outcome of attempt to recall patients suitable for this study
Number Percent Out come of recall 50 32.6 Came on time 47 30.7 Not come on time 22 14.3 In correct address
11 7.2 Changed address (moved) 5 3.3 Incorrect number
5 3.3 Far distance (difficult come back) 5 3.3 No response to frequent messages 4 2.6 Absent number in the network 4 2.6 Interrupted service
153 100 Total
Results
The failure rate of RCT in this study was 16%.
Forty of patients were female and 10 of them were male. None of men’s teeth were failed.
Out of 40 females 8 teeth were failed. There were no statistically significant differences in failure rates between two genders (P=0.14).
There were no statistically significant relation between age and failure rate (P=0.19) (Table II).
The failure rate in anterior, premolar and molar teeth were 12.5%, 20% and 25% respectively.
The statistically significant differences in these groups were not shown (P=0.3) (Table III).
The root canal therapy in 7 of (14.5%) appropriate and 1 of (50%) inappropriate coronal restoration were failed. There were no statistically significant differences between two groups (P=0.3).
None of under filled, 2 of (22.2%) over filled and 6 of (15%) appropriate filled root were failed. These differences were not statistically significant (P=0.79).
There was a statistically significant difference between pre and post treatment fistula (P=0.004) (Table IV) and Pre and post treatment sensation to percussion (P=0.004) (Table V).
Table II- Absolute and relative frequency of RCT failures according to age Total III (50-69)
II (30-49) I (10-29)
Number (%) Number (%)
Number (%) Number (%)
Age Failure of RCT
8 (16) 3 (33.3)
3 (14.3) 2 (10)
Yes
42 (84) 6 (66.7)
18 (85.7) 18 (90)
No
50 (100) 9 (100)
21 (100) 20 (100)
Total
Table III- Absolute and relative frequency of RCT failures according to the type of tooth Total Molar
Premolar Anterior
Number (%) Number (%)
Number (%) Number (%)
Type of tooth Failure of RCT
8 (16) 2 (25)
2 (20) 4 (12.5)
Yes
42 (84) 6 (75)
8 (80) 28 (87.5)
No
50 (100) 8 (100)
10 (100) 32 (100)
Total
Table IV- Absolute and relative frequency of studied patients according to failure of RCT and fistula before and after therapy
Post treatment Pre treatment
No Yes
No Yes Fistula Failure of RCT
7 1
5 3
Yes
14.3 100
12.5 30
Percent
42 0
35 7
No
85.7 0
87.5 70
Percent
49 1
40 10
Total
100 100
100 100
Percent
Table V- Absolute and relative frequency of studied patients according to failure of RCT and sensation to percussion before and after therapy
Post treatment Pre treatment
No Yes
No Yes
Sensation to percussion Failure of RCT
7 1
6 2
Yes
15.5 20
16.6 14.3
Percent
38 4
30 12
No
84.5 80
83.4 85.7
Percent
45 5
36 14
Total
100 100
100 100
Percent
Discussion
Among different evaluating factors considered in this study, Gingival fistula and sensation to percussion were proven to be significantly responsible for root canal therapy failure (Mc Nemar test, P = 0.004). The endodontic failure rate was 16%, which means 84% success rate.
This agrees with Sjogren and Hagglund study that reported 86% success rate in teeth with periapical lesions.(6) Barbakow et al also reported 89% success rate in their study.(3) The fact that obturation has an effect on reduction of inflammation can explain the fairly high success rate of endodontic treatment in teeth with apical periodontitis.(5) Although general sense is that overfilling or under-filling of teeth during treatment results in a higher percentage of endodontic failure, it should be considered that not all overfilled or under filled teeth leads to treatment failure.(7)
In this study, from nine over filled cases and one under filled endodontically treated teeth only 2 over filled cases was failed (the lesions were unchanged), while in the other patients periapical repair occurred. This is similar to Halse and Molven findings which periapical repair in overextended gutta-percha and cloropercha cases has been shown.(8)
Szajkis and Tagger Also reported periapical lesion healing in some retreated cases despite incomplete root canal debridement and filling.(9)
They stated that retreatment of these teeth reduced the amount of irritants from root canal system to a level below that is necessary for
maintaining a measurable periapical reaction, on the other hand, seepage of irritants from the oral cavity through lacy coronal restoration and root canal fillings was stopped as soon as these were replaced which resulted in resolution of periapical lesion.(9) It is worth mentioning that in one case the size of periapical lesion was reduced radiographically, despite the persistence of fistula. Although three endodontists considered it as a successful case, since the fistula was present, it was recorded as a failure.
Root perforation in one case resulted in extraction. Periodontal disease in three cases led to failure. Coronal restorations were inappropriate in two cases, in one of them endodontic treatment was failed. There fore, Root canal treatments in 8 patients were failed.
Five of these patients were below 50 and three were over 50 years old.
From 8 endodontic treatment failure cases, 4 cases were anterior and the other 4 were posterior teeth.
Chi-square and Fisher’s exact test, showed no significant difference between the extension of root canal filling, type of coronal restoration, type of teeth, periodontal disease, root perforation, age and endodontic failure, which maybe due to the small sample size.
Conclusion
The low failure rate in endodontically treated teeth with periapical lesion can be on explanation that obturation has a definitive effect on reducing Inflammation in periradicular area.
References:
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