|Year : 2020 | Volume
| Issue : 1 | Page : 39-44
Radiographic evaluation of root canal treatments performed by undergraduate students at the Dakar Dental School
Khaly Bane1, Seydina Ousmane Niang1, Mamadou Lamine Ndiaye2, Ghassen Zaafouri1, Babacar Touré1
1 Department of Conservative Dentistry and Endodontics, Faculty of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University of Dakar, Senegal
2 Department of Maxillofacial Radiography, Faculty of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University of Dakar, Senegal
|Date of Submission||09-Apr-2019|
|Date of Decision||23-Apr-2019|
|Date of Acceptance||07-Jun-2019|
|Date of Web Publication||27-Dec-2019|
Prof. Khaly Bane
Department of Conservative Dentistry and Endodontics, Faculty of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University of Dakar, BP 5005
Source of Support: None, Conflict of Interest: None
Aim: The aim of this study is to assess radiographically the technical quality of root canal treatments (RCTs) performed by students at the Dakar Dental School.
Materials and Methods: Out of 420 patients who had undergone RCTs, 501 teeth were randomly selected. Forty-eight teeth were excluded and the final sample involved 453 endodontically treated teeth. The length and the density of the root filling were evaluated for each filled root of each tooth. The presence of procedural errors was also evaluated. Descriptive statistics were used for expressing the frequencies of criteria and Chi-square test was used for comparing qualities of RCTs in terms of tooth locations, tooth types and academic level of students. The level of students, the significance level was set at 0.05.
Results: From the 453 RCTs, 63.6% were acceptable. The rate of adequate RCTs was higher in the maxilla than in the mandible (P = 0.022) and in the premolars (75.5%) followed by the anterior teeth (69.7%) and the molars (49.2%) (P = 0.026). The difference was not significant in terms of level of students (P = 0.429). Inadequate density was found in 27.8%, whilst underfilling and overfilling were found in 26.5% and 7.3%, respectively. The frequency of procedural errors was 2%.
Conclusion: The technical quality of RCTs performed by undergraduate students at the Dakar Dental School using step-back preparation and cold lateral condensation was classified as acceptable in 63.6% of the cases.
Keywords: Procedural errors, radiographic evaluation, root canal treatment, undergraduate dental student
|How to cite this article:|
Bane K, Niang SO, Ndiaye ML, Zaafouri G, Touré B. Radiographic evaluation of root canal treatments performed by undergraduate students at the Dakar Dental School. Saudi Endod J 2020;10:39-44
|How to cite this URL:|
Bane K, Niang SO, Ndiaye ML, Zaafouri G, Touré B. Radiographic evaluation of root canal treatments performed by undergraduate students at the Dakar Dental School. Saudi Endod J [serial online] 2020 [cited 2020 Oct 27];10:39-44. Available from: https://www.saudiendodj.com/text.asp?2020/10/1/39/274190
| Introduction|| |
The fundamental objective of root canal treatment (RCT) is to preserve the natural teeth. This objective is achieved by eliminating or significantly reducing bacterial populations and avoiding recontamination.,, The isolation of the surgical field with rubber dam and asepsis provides a hygienic environment. The elimination or significant reduction of pathogenic bacteria populations is only possible with careful cleaning and shaping, which will be supplemented by an acceptable root canal obturation. The objective of the latter is to create a fluid-tight seal along the walls of the pulp cavity from the opening of the crown to the apical ends. The root canal obturation is a tridimensional filling of the canal, historically achieved with gutta-percha and sealer to prevent a reinfection of the canal space. The presence of voids inside an inadequate root canal filling can contain bacteria. These bacteria could feed from the nutrients present in the periapical region or lateral canal, which can negatively influence the treatment outcome.
The technical quality of RCTs performed by students in dental schools has been evaluated around the world.,,,,,, This evaluation identifies the most frequent difficulties and errors encountered by students in order to improve the educational program and the quality of care provided in university hospitals in particular and in their future practice in general.
In Senegal, endodontic treatments performed by students have never been evaluated. Thus, the aim of this study was to assess radiographically the technical quality of RCTs (length and density) performed by undergraduate students at the Dakar Dental School and to determine whether the technical quality of RCTs was related to the teeth location and type and the academic level of the students.
| Materials and Methods|| |
This was a retrospective cross-sectional study carried out at the Dakar Dental School during the period 2016–2018. During this period, 420 patients received RCTs and 501 teeth were randomly selected. Forty-eight teeth were excluded and the final sample involved was 453 endodontically treated teeth. The study was approved by the Ethics Committee of the Cheikh Anta Diop University of Dakar, Senegal (No. 0027/FMPOS/DOS).
Criteria for endodontic records to be included in the study consisted of being performed by 4th- and 5th-year students from October 2016 to October 2018. Cases with age outside the range from 18 to 68 years and those with radiographs with unsatisfactory quality were excluded from the study.
The RCTs were accomplished accordin to a standard method. After administering local anesthesia if necessary, isolation with rubber dam was performed and an endodontic access cavity was made. Afterward, the working length was determined using radiograph with K-file instrument. The shaping technique used was step-back hand instrumentation with K-files (VDW GmbH, Munich, Germany). All canals were irrigated with sodium hypochlorite (0.5%). All teeth were obturated with gutta-percha points of 0.02 taper (VDW GmbH, Munich, Germany) and AH Plus sealer (Dentsply DeTrey GmbH, Konstanz, Germany), using cold lateral condensation technique.
For each RCT, preoperative, working length determination, and postoperative radiographs were taken by the bisecting angle technique, using a dental radiography machine (DeGotzen, Roma, Italy) and E-speed #2 intraoralfilms (Primax, Berlin, Germany). All RCTs were performed under the supervision of endodontic staff. The teacher/student ratio at the time of the study was 1/7. For each treated tooth, the quality of RCT was assessed by examining all three radiographs. The root filling in each canal was categorized as acceptable or unacceptable according to the criteria used by Khabbaz et al. [Table 1]. Procedural errors were also assessed according to the criteria used by the same authors [Table 2]. For monoradiculated teeth, RCT was considered acceptable if the root canal filling was of acceptable length, adequate density, and free of procedural errors. For a multirooted tooth, all canals were evaluated simultaneously and the technical quality was considered acceptable only when the technical quality is acceptable for all the root canals.
All radiographs were assessed by two independent researchers in a dark room using a high-quality magnifier. The radiographs were mounted in a cardboard slot to exclude outside light and measurements were made with a transparent ruler graduated to an accuracy of 0.5 mm. Afterward, the results were compared, and the researchers came to a consensus. In case of disagreement, a third investigator (experienced maxillofacial radiologist) was asked to evaluate the radiographs and a final agreement was reached. Strength of interobserver agreement was measured using Kappa value.
The statistical analysis was carried out using the SPSS software (version 18.0, Chicago, IL, USA). Descriptive analyses were used to express the frequencies of the radiographic criteria for RCT quality. The Chi-square test was used to compare results among tooth location, tooth type, and student academic year. P < 0.05 was considered statistically significant.
| Results|| |
The distribution of the treated teeth according to their location showed a predominance of maxillary teeth (57.6%) compared to mandibular teeth (42.4%). Depending on the tooth type, molars were the most treated teeth (39.1%) followed by premolars (32.4%), and finally, the anterior teeth (28.5%) [Table 3]. The 4th- and 5th-year students treated 42.4% and 57.6% of the teeth, respectively. Fourth-year students treated more anterior teeth and premolars, while 5th-year students treated more molars and premolars.
|Table 3: Quality of root canal treatments according to tooth type and location|
Click here to view
According to the length and density of root canal filling and the presence of procedural errors, acceptable RCTs were found in 63.6% of the treated teeth. Concerning teeth location, 71.3% of treatments were acceptable in the maxilla compared to 53.1% in the mandible, the difference is statistically significant (P = 0.022). Acceptable treatments were more frequent in the premolars with a rate of 75.5%, followed by the anterior teeth (69.7%) and the lowest rate was found in the molars (49.2%). The difference is statistically significant (P = 0.026). According to the academic level of the students, 67.2% of the RCTs performed by 4th-year students and 60.9% by the 5th year were adequate (P = 0.429) [Table 4].
|Table 4: Quality of root canal treatments according to academic year of students|
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The results showed that inadequate density was found in 27.8% of the treated teeth, underfilling in 26.5%, and overfilling in 7.3% of the treated teeth. Inadequate density was the most frequent cause of inadequate root canal filling, followed by underfilling and overfilling, both in the maxilla and mandible [Table 3]. Procedural errors occurred in 2% of treated teeth, and it was limited to separated instruments in molars and only concerns 4th-year students.
| Discussion|| |
This study was carried out in order to assess radiographically the technical quality of RCTs performed by students at the Dakar Dental School. The density and length of the root canal filling and the procedural errors used in this study as evaluation criteria are also used in many other similar studies.,,,,
To limit interinvestigator and intrainvestigator discrepancies, radiographic criteria were strictly defined and two investigators were calibrated before the study. A good agreement between the investigators was noted because the k-values were 0.86 (adequate root canal fillings) and 0.81 (treatments without procedural errors).
According to defined criteria, the acceptable RCTs were found in 63.6% of treated teeth. It is comparable to the finding of one study, higher than some studies ,,, and less than other studies., This could be due to differences in the sample selection and criteria used by these studies.
Concerning the teeth location, a significant difference was found between the quality of maxillary and mandibular RCTs. The best results obtained in the maxilla were certainly related to the fact that students often have difficulty in successfully performing anesthesia in the mandible. Failures of anesthesia in the mandibular teeth are often mentioned in the endodontic literature and considered as additional difficulties for the realization of RCTs, especially for inexperienced students.
The highest rates of acceptable RCTs were found in premolars, and anterior teeth. Other authors who have worked on the subject have corroborated the results of our study., The lowest rates of adequate RCTs observed in the molars were due to the tooth position and complexity of the root canal morphology.
In relation to academic level, it was noted that the rate of inadequate RCTs was higher if they were performed by 5th-year students compared to those performed by 4th-year students. This difference was statistically insignificant and could be explained by the fact that 4th-year students performed more treatments on monoradiculated teeth, while 5th-year students performed more treatments on molars, the latter teeth are often the most difficult to treat. These results are comparable to those reported by other authors.,,
Density is a factor that can influence the technical quality of root canal filling. Nondense root canal filling can lead to treatment failure. The most common cause for unacceptable root fillings in our study was inadequate density. This result was certainly related to the root canal filling technique used by the students. Indeed, the cold lateral condensation of gutta-percha has a less adequate density compared to other compaction techniques.
The rate of root canal fillings of adequate length (0–2 mm to the radiological apex) was 63.6%. This result is consistent with those reported by several other authors ,,, ranging from 62-69.6% and less than those reported by Kelbauskas (84.1%), Saatchi et al.(80.7%), and Unal et al.(84.3%). The length measured on periapical radiographs is often inaccurate, so there is a certain threshold of what is considered to be a correct filling. Some authors stated a 0.5–2 mm distance from the end of the filling to the root apex as adequate, while others set this limit at 0–3 mm.
Underfillings represent 26.5% of cases, the highest rate being the molars. This result is inconsistent with those reported by other authors., These default errors, which are more important in molars, were due to the complex anatomy of these pluriradiculated teeth as well as the presence of root curvatures that make it difficult for manual instruments to the corrected working length.
Overfillings were found in 7.3% of cases, which is comparable to the results reported by Barrieshi-Nusair et al.(4.2%). Higher percentages have been recorded in other studies., This could be explained by the presence of a higher number of teeth with a periapical radiographic image in these studies.,, Indeed, these lesions can lead to apical resorption and the destruction of apical constriction, which can influence the determination of working length by students. Most dental schools continue to use radiographs to determine the working length, which is the case at the Dakar Dental School. However, this method has many limitations due to the existence of external parameters (possible radiological deformations/distortions, variability of the apical root canal system, and operator-specific judgment) that can be avoided by the electronic method (use of apex locators). Indeed, many comparative studies between the two methods reported that radiography leads to frequent overestimation or underestimation of the working length, while apex locators make it possible to strongly limit these errors., Therefore, several countries have integrated the use of apex locators into preclinical and clinical endodontic education. Several models have been proposed to integrate the use of apex locator in preclinical education ,
Procedural errors were detected in 2% of the treated teeth, and it was limited to separated instruments. These errors were detected only in molars. Similar findings were also reported., These results were certainly related to the complex anatomy of the molars, which often have curved and narrow root canals. It should be noted that only 4th-year students were responsible for these procedural errors, which could be explained by their lack of experience and stress. In this study, ledge, foramen perforation, root perforation were not detected.
Stainless steel hand instruments are still used in many dental schools. The root canal shaping and filling techniques taught at the Dakar Dental School were step-back and cold lateral condensation technique. The use of rotary nickel–titanium instruments followed by compact warm gutta-percha would improve the technical quality of RCTs.,, Indeed, many studies have shown that the use of rotary nickel–titanium instruments has many advantages both in terms of ergonomics, the quality of root canal shaping, and the reduction of working time. With these instruments and in compliance with the recommendations, the objectives of root canal shaping and reduction of procedural errors are achieved.,,, At the same time, studies have shown that root canal filling techniques that compacted the hot gutta-percha give the best results in terms of limit and density compared to the cold lateral condensation technique ,, This is why some dental schools have introduced these techniques into the preclinical and clinical teaching of students.,, The nonuse of these techniques at the dental school of Dakar would certainly be linked to their costs.
Finally, it is important to stress that with the reform of the University system introduced at the Dakar Dental School 8 years ago; preclinical endodontics is taught in the 3rd year at a rate of 4 h/week. Demonstrations and training are done on phantoms with natural teeth. Clinical teaching is done in the 4th and 5th years at a rate of 2 h/week. As several studies have pointed out, the insufficient time devoted to preclinical and clinical training of students has a negative impact on the quality of RCTs regardless of the teacher: student ratio (1:7) at the Dakar Dental School at the time of the study.,,,,
| Conclusion|| |
The technical quality of RCTs performed by undergraduate students at the Dakar Dental School was classified as acceptable. Newer instruments and techniques must be incorporated into the preclinical and clinical training of students to improve the quality of RCTs.
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]