|Year : 2020 | Volume
| Issue : 1 | Page : 40-45
Causes of root canal treatment failure: A prospective study in Makkah City, Saudi Arabia
Mohsen K Aljabri1, Jamal A Kensara2, Ayman O Mandorah3, Monammed A Sunbul4
1 General Dentist, Al-Mandaq Primary Health Care Center, Al-Baha, Saudi Arabia
2 General Dentist, King Faisal Hospital, Makkah, Saudi Arabia
3 Endodontics Assistant Professor, Faculty of Dentistry, Taif University, Taif, Saudi Arabia
4 Consultant Endodontist, King Faisal Hospital, Makkah, Saudi Arabia
|Date of Submission||21-Apr-2019|
|Date of Decision||17-Jun-2019|
|Date of Acceptance||16-Sep-2019|
|Date of Web Publication||05-Feb-2020|
Dr. Mohsen K Aljabri
General Dentist, Al-Mandaq Primary Health Care Center, Al-Baha
Source of Support: None, Conflict of Interest: None
Aim: The aim of the study is to identify the causes of root canal treatment (RCT) failures in Makkah City.
Materials and Methods: The study used a prospective cohort study design, using a clinical examination, treatment, and follow-up. The study summarized the data of 131 patients presented to the Endodontic Department in King Faisal Hospital, Makkah, in the Western region of Saudi Arabia and included patients with failed RCT aged 16 years or older without any systemic disorder.
Results: Of the 131 patients, the most common factor for root canal failure was underfilling (71.0%), followed by coronal leakage (42.7%), overfilling (16.8%), missed canal (16.0%), iatrogenic (6.1%), leaked canal and anatomic (1.5%), and 3.1% for unknown causes. Fifty-two (39.7%) were female and 79 (60.3%) were male. One hundred and three (78.6%) were 18–40 years old, whereas 28 (21.4%) were 40 years old and older. For tooth type, 34 (26.0%) had an anterior root canal, 39 (29.8%) had a molar root canal, and 58 (44.3%) had a premolar root canal.
Conclusion: Considering the limitations of the present study, it was determined that endodontic treatment failures mostly occurred in underfilled root canals, followed in number by coronal leakage. Premolars had a higher failure rate than did anterior and molar teeth.
Keywords: Endodontic failures, root canal retreatment, root canal treatment
|How to cite this article:|
Aljabri MK, Kensara JA, Mandorah AO, Sunbul MA. Causes of root canal treatment failure: A prospective study in Makkah City, Saudi Arabia. Saudi J Oral Sci 2020;7:40-5
|How to cite this URL:|
Aljabri MK, Kensara JA, Mandorah AO, Sunbul MA. Causes of root canal treatment failure: A prospective study in Makkah City, Saudi Arabia. Saudi J Oral Sci [serial online] 2020 [cited 2022 Jul 2];7:40-5. Available from: https://www.saudijos.org/text.asp?2020/7/1/40/272413
| Introduction|| |
The target of endodontic management is to clean the root canal structure of the bacterially infected pulp tissue and perform detailed debridement to form and prepare the canal space to be packed with inert material, thus averting or reducing any probabilities of developing another infection. Nevertheless, when the treatment did not meet the standard clinical principles, failure ensued.
It is important and vital for a restoration to be well-sealed coronal to prevent access of any microorganisms. If taken for granted, an improper coronal seal will result in a potential factor for endodontic failure. The study by Ray and Trope emphasized how important proper coronal sealing was. Their study showed how teeth with improper coronal sealing fell short of success in proper coronal sealing. To have a successful projection of an endodontically treated tooth, it is important to have an invulnerable seal at the coronal area. The meta-analysis by Ng et al. reported a higher attainment rate for teeth with adequate restorations than for those teeth with poor-quality restorations.
Root canal treatment (RCT) results were gauged by signs and symptoms of periapical curing; most of the available methodical assessments examined detailed prognostic aspects of the resolution of clinical and radiographic marks of periapical disease.
Findings from some clinical studies stated that histological, clinical, or radiographic evaluation of healing (or a combination of these) could assess the success of retreatment after a particular follow-up period. Thus, it is the goal of this study to identify the causes of root canal failures to help the dentist avoid these mishaps as well as provide better retreatment.
The aim of the study is to identify the causes of root canal failures in Makkah City.
| Materials and Methods|| |
Ethical approval was received from the Institutional Review Board at King Fahad Medical City, number 17-464E.
This is a cohort prospective study; all the data were collected through clinical examination and demographic data.
This 12-month study was conducted between December 2017 and December 2018 at the Endodontic Department in King Faisal Hospital, Makkah, in the Western region of Saudi Arabia.
At first, the patient attended the screening clinic, where a general dentist, with consultation from an endodontist, diagnosed the case, and then the patient was scheduled for an appointment at the endodontic clinic.
The study included patients aged 16 years or over with failed RCT, without any systemic disorder, who could sign a consent form.
The study excluded patients younger than 16 years and those who had a systemic disorder.
During the patient's endodontic clinic appointment, vital questions were asked and a clinical examination was performed, including the uses of:
- Periapical X-rays showing the whole tooth, from the crown to beyond the root, where the tooth attaches to the jaw. Each periapical X-ray showed all teeth in one portion of either the upper or lower jaw. Periapical X-rays detect any unusual changes in the root and surrounding bone structures
- A percussion test was carried out by gently tapping adjacent and suspect teeth with the end of a mirror handle. A positive response indicated that a tooth was extruded due to exudate in apical or lateral periodontal tissue
- A cold test defined the responsiveness of pulpal sensory nerves to cold stimulus, which was practically carried out using ethyl chloride on a pledget of cotton wool.
These tests were used to probe the causes of RCT failures, determine retreatment with different rotary systems, and conduct follow-up afterward.
Study size and statistics
This study was analyzed using version 23 of IBM SPSS(IBM Corp, Armonk, NY, USA). An unbiased descriptive statistic was used to define the characteristics of the study variables by forming counts and categorical percentages. The Chi-square test was used to test the correlation between categorical variables. These tests were carried out with the normal distribution assumption. Finally, the criterion for rejecting the null hypothesis was the conventional P < 0.05.
| Results|| |
During the study, the total number of patients who came with root canal failure was 340. Sixty-four declined to participate in the study, 122 patients were referred for extraction, and 23 were referred for surgical retreatment, leaving 131 enrolled in the study for nonsurgical retreatment. This study discusses only nonsurgical retreatment.
Characteristics of the 131 study participants
The demographic data of the 131 study samples are presented in [Table 1]. Of 131 patients, 52 (39.7%) were female and 79 (60.3%) were male. One hundred and three (78.6%) were between 18 and 40 years old, whereas 28 (21.4%) were 40 years old and older. Thirty-four (26.0%) had an anterior RCT, 39 (29.8%) a molar RCT, and 58 (44.3%) a premolar RCT.
Causes of root canal treatment failures
[Figure 1] shows the causes of RCT failure. In 56 (42.7%) patients, failure was caused by coronal leakage; in 22 (16.8%), it was caused by overfilling; in 93 (71.0%), it was caused by underfilling; in 8 (6.1%), it was caused by an iatrogenic issue; in 21 (16.0%), it was caused by a missed canal; in 2 (1.5%), it was caused by a leaked canal; and in another 2 (1.5%), it was caused by an anatomic complication; and four (3.1%) revealed reported unknown causes.
Causes of root canal treatment failure in relation to gender
[Table 2] presents the origins of failure of endodontics by gender. It was noted in the first cause of failure, which was coronal leakage, that out of 56 patients who reported failure caused by coronal leakage, 32 (57.1%) were female and 24 (42.9%) were male. Eight (26.4%) females and 14 (63.6%) males out of 22 respondents reported failure caused by overfilling; 59 (63.4%) females and 34 (36.6%) males out of 93 reported failure caused by underfilling; 6 (75.0%) females and 2 (25.0%) males out of 8 reported failure caused by iatrogenic causes; 11 (52.4%) females and 10 (47.6%) males out of 21 reported failure caused by a missed canal; 8 (100.0%) males reported failure caused by a leaked canal; 2 (100.0%) females reported failure caused by anatomic issues; and 2 (50.0%) females and another 2 (50.0%) females reported failure from unknown causes. A statistically significant (P< 0.05) higher failure rate per gender was found for the overfilling and unknown groups.
Causes of root canal treatment in relation to age
[Table 3] shows the causes of failure by age. Of 56 respondents whose failure was caused by coronal leakage, 50 (89.3%) of them were between 18 and 40, whereas 6 (10.7%) were 40 or older. For respondents who reported failure caused by overfilling, 18 (81.7%) of them were between 18 and 40 and 4 (18.2%) were 40 or older. For failure caused by underfilling, 71 (76.3%) patients were between 18 and 40, whereas 22 (23.7%) were 40 or older. For failure caused by iatrogenic reasons, 8 (100.0%) were in patients between 18 and 40 and none were 40 or older. Failure caused by missed canal occurred in 17 (81.0%) patients between 18 and 40; 4 (19.0%) were 40 or older. Failure caused by leaked canal occurred in two (100.0%) patients, 40 or older, but none occurred in patients between 18 and 40. Failure caused by anatomic complications two (100.0%) in patients between 18 and 40 and none did among those 40 or older. Failure for unknown causes occurred in two (50.0%) patients between 18 and 24, whereas two (50.0%) occurred in patients with 40 or older. A statistically significant (P< 0.05) higher failure rate per age was found among the coronal leakage and leaked canal groups.
Cause of failure in relation to tooth type
[Table 4] shows the causes of failure per type of tooth. Of 56 respondents who reported failure caused by coronal leakage, 20 (25.7%) of them were found in anterior teeth, 16 (28.6%) were found in molars, and 58 (44.3%) were found in premolars. Out of 22 respondents who reported failure caused by overfilling, 2 (9.1%) responded that infection was found in anterior teeth, six (27.3%) in molars, and 14 (63.6%) in premolars. Of the 93 respondents who reported underfilling, 24 (25.8%) responded that infection was found in anterior teeth, 27 (29.0%) in molars, and 42 (25.2%) in premolars. Of the eight respondents who reported failure caused by iatrogenic origin, 2 (25.0%) responded that infection was found in a molar, whereas 6 (75.0%) were in a premolar. Of the 21 respondents who reported failure caused by a missed canal, 9 (42.9%) responded that infection was found in a molar, whereas infection was found in 12 (57.1%) patients' premolars. The two (100.0%) respondents who reported failure caused by a leaked canal both responded that infection was found in a premolar. Of the two respondents who reported failure caused by anatomic issues, both (100.0%) responded that infection was found in a molar, and finally, the four (100.0%) respondents who reported failure from unknown causes found infection in a molar. A statistically significant (P< 0.05) higher failure rate per type of tooth was found in the missed canal and unknown groups.
| Discussion|| |
Failures occurred in a small to great number of cases regardless of the high success rate in endodontic treatment. This study reported that the most corporate factor of letdown was underfilling, (71.0% of 131), followed by coronal leakage (42.7%), 16.8% for overfilling, 16.0% for missed canal, 6.1% for iatrogenic reasons, 1.5% for a leaked canal and anatomic reasons, and 3.1% for unknown causes.
The findings of this study were compatible with the studies done by Rasheed et al., in which they disclosed that the most usual factor of failure in RCT, usually present in both maxillary and mandibular molars and premolars, was underfilling (42%), unfilled (20%), and poor lateral condensation (22%). The same result was shown in the study by Iqbal, wherein he revealed that the constituent most liable for failures in RCT were underfilled canals (33.3%), unfilled canals, and missed canals (17.7%). There were comparable findings from other studies, supporting the findings of this study, stating that the eminence of the root canal filling can affect the presaging of endodontic management., However, a few factors also showed a gap in the results of the present study. In Iqbal's study, the fewest endodontic failures were seen in the 21–30 (24.44%) age group, and the generality of the endodontic failures was remarked on in the 41–50 age group (41.11%). Unlike these findings, Swartz et al. and Dammaschke et al. commented that, regarding the success rate of RCT s, no effect was seen regarding age. In the current study, endodontic failures were noted in the 18–40 age range. Moreover, according to tooth type, as presented in the past studies, most of the endodontic failures were noted in maxillary molars (44.4%), followed by mandibular molars (20%) and last, maxillary premolars (15.5%), whereas in the present study, a majority of the endodontic failures were marked in premolars. An important factor in the long-term success of endodontic treatment was also acknowledged, with studies mentioning the importance of good-quality density of root canal filling. Studies reported that substandard fillings could result in endodontic treatment failure due to microleakage from the root canal walls. Inadequate root fillings occurred in 71% of overfilled canals and in 6.1% of underfilled ones in the present study. The results were consistent with the prior study by Barrieshi-Nusair et al., which recorded meager fillings in 27.4%, and the study by Dadresanfar et al., which noted 29.3% for poor fillings. These results, however, differ from other studies., In addition to the adequacy of density in root canal stuffing, according to Burke et al., the length and/or measurement of the root canal filling is the most substantial factor for success of an endodontically managed tooth.
Similar to the present study, Barrieshi-Nusair et al. and Peak et al. conveyed that underfillings comprised 34% in their studies, in contrast to the discoveries by Dadresanfar et al. and Er et al., who recorded only 18% of underfillings. In addition, compared to other studies, the present study revealed a high occurrence of failure on premolar teeth. This was differently reported from various past studies, wherein they were the least common teeth to experience root canal failure. A major determinant of failures in endodontic treatment and persistence of disease was the inability to distinguish and access areas that were infected.
Nonsurgical endodontics is a therapy with a high success rate. There are cases that present with restorative or intracanal impediments, rendering retreatment a poor choice. Removal of large restorations or posts may preclude restoration of the tooth. Some separated instruments, especially those located in the apical third, may not be retrievable or might be bypassed. Often canals are ledged or transported in a manner that makes them inaccessible. Although this approach does not treat the entire canal system, current surgical techniques and materials can address 6 mm or more of the canal system and offer a high success rate.
There are moments when posttreatment disease can necessitate further interference in spite of nonsurgical root canal therapy's high success rates. Four possible causes of posttreatment endodontic disease were mentioned in some studies. First are withheld or reestablished microorganisms in the canal system. Second are the microorganisms that survived in the apical tissues outside of the canal system. Third are the foreign-body responses in apical tissue, and last is the existence of true periapical cysts.,
Likewise, there are four options for treatment of a tooth in the event of issues after RCT, which are extraction, nonsurgical retreatment, surgical treatment, and doing nothing. A feasible option is extraction and replacement; however, it was reported that it is better to replace a missing tooth than a restorable natural tooth. Endodontic retreatment is when an endodontist reopens the tooth and takes off the filling placed in the root canals in the course of the first procedure. A thorough examination of the tooth is performed in cases of new infections. Ways to avoid complications were also mentioned in the past studies, such as by removal of the dentin overhanging the canal orifice. One should also pay attention to the essence of the filling material and physical assets of endodontic equipment during reinstrumentation of the filled canal.
In the study by Ng et al., the accumulated chances of tooth persistence for 2–10 years succeeding RCT ranges from 86% to 93%. The accuracy of the prognostic aspects for tooth survival was quite feeble. Moreover, they determined through studies and analysis four conditions that significantly improve tooth survival. These conditions are teeth with mesial and distal proximal contacts, teeth renovated with a crown after management, nonmolar teeth, and teeth not operating as abutment for a removable or fixed prosthesis. Thus, the need was emphasized for long-term prospective research and studies with thorough and in-depth data to delve more into factors for RCT development.
| Conclusion|| |
Considering the limits of this study, it was determined that the aforementioned causes of failure occurred in underfilled root canals most, followed by coronal leakage. Premolars had greater degrees of failure vis-à-vis anterior and molar teeth. Symptoms of infection and causes of RCT must be considered while accomplishing endodontic management and nonsurgical retreatment. Providing keen attention to specifics would not merely improve the quality of endodontic superiority but also increase the probability of success.
Data availability statement
The raw data was generated at King Faisal Hospital in Makkah. Resultant data supporting the findings of this study are available from the corresponding author, MA, on request.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]