|Year : 2021 | Volume
| Issue : 3 | Page : 153-157
Evaluation of root canal morphology of mandibular premolars using cone-beam computed tomography in Rajasthan subpopulation - A retrospective study
Neha Mittal, Prachi Mital, Ashwini B Prasad, Deepak Raisingani, Lalita Poonia, Garima Udawat
Department of Conservative Dentistry and Endodontics, Mahatma Gandhi Dental College and Hospital, Jaipur, Rajasthan, India
|Date of Submission||06-Jun-2021|
|Date of Decision||13-Jul-2021|
|Date of Acceptance||01-Sep-2021|
|Date of Web Publication||30-Sep-2021|
Dr. Neha Mittal
Department of Conservative Dentistry and Endodontics, Mahatma Gandhi Dental College and Hospital, Jaipur, Rajasthan
Source of Support: None, Conflict of Interest: None
Aim: The purpose of this study was to evaluate root canal morphology in mandibular first and second premolars among Rajasthan subpopulation in Jaipur city using cone-beam computed tomography (CBCT).
Materials and Methods: CBCT scans of 740 fully erupted mandibular first and second premolars were taken and assessed by two endodontists. Inter-examiner reliability was determined.
Results: The root canal morphology of 380 permanent mandibular first premolars was assessed which showed canal configurations of Type I in 73.5%, Type V in 11.57%, Type IV in 8.42%, Type III in 2.63%, Type II in 2.1%, Type VII in 2.1% and Type VI and VIII 0% of the scans. The root canal morphology of 360 permanent mandibular second premolars was assessed which showed canal configurations of Type I in 88.88%, Type II in 7.77%, Type IV in 2.2%, Type III and Type V in 0.55%, Type VI, VII, VIII in 0% respectively of the scans.
Conclusion: The majority of the population in Rajasthan have Vertucci's Type I configuration in both mandibular first and second premolars. However, other canal configurations can also be found in these teeth.
Keywords: Cone-beam computed tomography, premolars, root canal, Vertucci
|How to cite this article:|
Mittal N, Mital P, Prasad AB, Raisingani D, Poonia L, Udawat G. Evaluation of root canal morphology of mandibular premolars using cone-beam computed tomography in Rajasthan subpopulation - A retrospective study. Endodontology 2021;33:153-7
|How to cite this URL:|
Mittal N, Mital P, Prasad AB, Raisingani D, Poonia L, Udawat G. Evaluation of root canal morphology of mandibular premolars using cone-beam computed tomography in Rajasthan subpopulation - A retrospective study. Endodontology [serial online] 2021 [cited 2022 May 22];33:153-7. Available from: https://www.endodontologyonweb.org/text.asp?2021/33/3/153/327265
| Introduction|| |
The knowledge of root canal anatomy and morphology is required for successful diagnosis and treatment planning for endodontic therapy. Evaluation of complex anatomical variations is necessary for proper modification of treatment protocol, helping the clinician to perform a good root canal therapy.
Mandibular premolars are one of the most challenging teeth to treat endodontically due to comparatively wide variations in root canal morphology than other teeth.
These variations are the most common reason for frequency of endodontic flare-ups and failures during root canal therapy.
Several investigators have classified root canal and their variations. The most widely used system is the Vertucci classification, where he classified root canal into eight categories: Type I (1), Type II (2-1), Type III (1-2-1), Type IV (2), Type V (1-2), Type VI (2-1-2), Type VII (1-2-1-2), and Type VIII (3).
Clinical examination and conventional periapical radiographs are traditional ways to identify the morphological variations of root and root canals, but they are time-consuming and can lead to sample destruction too. On the other hand, cone-beam computed tomography (CBCT) and micro-computed tomography are three-dimensional (3D) imaging modalities which provide more accurate and high-resolution images with low sample destruction rate.,
Thus, CBCT is preferred to study anatomical variations of root canal as it provides noninvasive 3D images and complete morphological details., Therefore, the purpose of this study was to evaluate the root canal morphology of mandibular premolars in Rajasthan subpopulation using CBCT scans.
| Materials and Methods|| |
This retrospective study was conducted at 3D Solutions, a diagnostic center in Jaipur, Rajasthan. Written consent was taken at the diagnostic center, and ethical clearance was obtained by the institution review board. The CBCT scans of patients who visited the center from January 2018 to January 2019 were viewed, and CBCT images, inclusive of mandibular premolars, were selected.
The inclusion criteria were as follows:
- Teeth without restorations
- Teeth without periapical lesions
- Nonendodontically treated teeth
- Fully mature teeth.
The exclusion criteria were as follows:
- Extensively carious teeth
- Root resorption
- Teeth with prosthesis
- Teeth in close proximity to implants (excluded to avoid the artifacts and related errors).
All images were taken using a Carestream 9300, 3D CBCT machine operating with exposure parameter of 60 kV and 2.0 mA along with an exposure time of 12 seconds. CBCT images of mandibular premolars were observed with inbuilt CS 3D imaging software using a Dell workstation at the diagnostic center by two endodontists within one week. All the samples were evaluated simultaneously and separately, and a consensus was reached.
Inter-examiner reliability was determined by assessing and using the intraclass correlation coefficient (ICC).
The kappa coefficient for the first premolar was 0.852, which depicted that there was an overall near-complete agreement between the two observers (k > 0.8).
The kappa coefficient for the second premolar was 1.000, which depicted that there was an overall complete agreement between the two observers (k = 1.000).
ICC values >0.75 indicate good reliability between the examiners. Kappa score of 0.81–1.00 depicts near-complete agreement between the examiners.
All three spatial planes (especially axial and sagittal) in the CBCT sections were examined from the cementoenamel junction to the apex, and the number of roots and canal configuration were illustrated and recorded according to Vertucci's classification.
| Results|| |
The canal morphology of 380 permanent mandibular first premolars assessed according to Vertucci's classification showed the highest percentage of Type I canal configuration which was 73.5%. Type V (11.57%), Type IV (8.42%), Type III (2.63%), and Type II and VII (2.1%) configurations were also seen in significant numbers [Table 1].
The canal morphology of 360 permanent mandibular second premolars assessed according to Vertucci's classification showed the highest percentage of Type I canal configuration which was 88.88%. Canal morphology of Type II was seen in 7.77%, Type IV in 2.2%, Type III and Type V in 0.55%. Type VI, VII, VIII were not seen (0%) [Table 2].
The male population in the study showed higher percentages of different canal configurations [Table 3] and [Table 4] than the female population in both permanent mandibular premolars. Female population depicted less diversity, with Type I canal morphology being the highest in number in both mandibular premolars [Table 3] and [Table 4].
|Table 3: Canal Morphology in Males and Females in Mandibular First Premolars|
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|Table 4: Canal Morphology in Males and Females in Mandibular Second Premolars|
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In comparison between the first and second premolars, it was observed that the mandibular first premolars showed a greater variation in canal morphologies [Chart 1].
In both mandibular first and second premolars, a single canal was most prevalent. First premolars had one root canal in 89.4% of cases, followed by two root canals in 10.5% of cases. Second premolars had one root canal in 90.5% of cases, followed by two root canals in 9.4% of cases [Chart 2]. Three root canals were not observed in any of the teeth.
| Discussion|| |
The success rate of root canal treatment is likely to be reduced if a root canal system is not adequately cleaned and obturated. The root canal system of the mandibular premolars poses a greater challenge at every operatory step. Thus, it is necessary to assess the canal morphology in accordance with the number of canals present and the course of the canals before beginning the root canal treatment.
Various studies have been conducted among Indian population so as to increase the knowledge on anatomy of premolars. The results of the present study are in accordance with the study conducted by Velmurugan and Sandhya on mandibular first premolar teeth using decalcification and clearing technique. They concluded that the canal patterns of the mandibular first premolars were classified as Type I (72%), Type II (6%), Type III (3%), Type IV (10%), and Type V (8%), which matches to the Vertucci's classification.
The mandibular premolars from endodontic perspective exhibit higher failure rates (11.7%) when compared to other teeth, which to a large extent can be attributed to the variable root canal morphology, and inability to access extra canals. This observation was supported by Iyer et al. who studied 500 patients using radiovisiography, among whom 123 patients (24.6%) showed anatomical variance in the canal configuration. There was a higher incidence of Vertucci's Type IV canal configuration when compared to Type V, Type II, and Type VIII.
The South Indian population were exposed to an experimental study wherein they presented Vertucci's Type I (83.81% and 93.48%, respectively) canal morphology as the most common in mandibular first and second premolars followed by Type V (11.97% and 3.5%, respectively), similar to the present study results for mandibular first premolars, i.e. Type I (73.5%) being the most common followed by Type V (11.75%) canal configuration [Table 1].
Parekh et al. in 2011 compared the internal anatomy of first and second mandibular premolars by clearing technique to study different percentage variations of root canal morphology in Gujarat population. Root canal morphology of mandibular first premolar showed a higher variation (75%) when compared to the mandibular second premolar (37.5%). The results in this study concur with this finding [Chart 1]. This has a clinical significance as the knowledge of variations in the root canal morphology can enhance the level of endodontic treatment of mandibular premolars.
Another in vitro study carried out in 2015 in Gujarat by Patel et al. using clearing technique concluded that, among the 100 mandibular first premolar teeth, 78% had Type I canal morphology with Type II, Type IV, Type V, Type VI, and Type VII canals being seen in 1%, 2%, 13%, 2%, and 1% of the teeth, respectively. Similarly, the CBCT scans observed in the current study had 73.5% as Type I canal pattern, with Type II, Type III, Type IV, Type V, and Type VII [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d, [Figure 1]e, [Figure 1]f identified as 2.1%, 2.63%, 8.42%, 11.57%, and 2.1%, respectively.
|Figure 1: Cone-beam computed tomography images of canal morphologies in mandibular premolars; a) Type I canal morphology, b) Type II canal morphology, c) Type III canal morphology, d) Type IV canal morphology, e) Type V canal morphology, f) Type VII canal morphology|
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In the present study, first premolars had more variations in roots and canal systems as compared to the second premolar [Chart 1]. Another study conducted by Hajihassani et al. using CBCT in a defined group of dental patients in Iran presented with a single root in 95.97% in mandibular first premolars and 100% of cases in mandibular second premolars. The results of our study showed similarity with mandibular first and second premolars having a single root canal in 73.5% and 88.88% of cases, respectively [Table 1] and [Table 2]. Yu et al. and Mirzaei et al. also reported the presence of more than one root more in the first premolars than in the second premolars.
Matherne et al. reported the superiority of computed tomography over other diagnostic methods in locating the additional canals. In this study, axial images of CBCT were used to confirm the additional roots or canals. Thus, CBCT imaging is not only noninvasive but also highly sensitive method for morphological studies. In clinical practice, two or more root canals may be overlapped in periapical radiographs, and thus, CBCT scan is reliable to confirm the presence of multiple roots or canals.
Shetty et al., in 2012, acknowledged applications of CBCT and stated that endodontics is the second most common reason for taking a CBCT (25.6%) after oral and maxillofacial surgery (26.3%) of all the different dental specialties. CBCT scans accompany a great advantage to assess the complexity of root canal morphology and plan an appropriate endodontic treatment accordingly.
The reliability and the accuracy of CBCT in determining extra roots and canals was a major reason to use this method for the purpose of carrying out this study in Rajasthan population.
The mandibular first premolar tooth had a higher incidence of more than one canal system (24.2%) and more than one apical foramen (21.1%) in weighted studies.
Little literature is available on incidence of multiple canals in mandibular second premolar using CT scan and in Indian subpopulation. This study provides supplemental information about mandibular first and second premolars in Rajasthan population.
The limitation of this study was that the clinical impression is not available for the studied CBCT scans.
| Conclusion|| |
The clinician should have accurate knowledge of tooth anatomy as well as canal variations. Root canal variations among mandibular premolar vary greatly. Within the limitations of this study, it can be concluded that mandibular first premolars exhibited Vertucci's Type I configuration most commonly which was followed by Type V. Mandibular second premolars exhibited Vertucci's Type followed by Type II pattern commonly. Majority of the mandibular first and second premolars in this study had a single canal followed by two canals. Three canals were not observed in this study.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]