Bridging the gap in aberrant root canal systems: Case series

Abstract

Endodontic success depends on accurate diagnosis, complete debridement of diseased pulp tissue, and adequate disinfection of the root canal system. It is essential to have a solid grasp of root canal variations. Inadequate knowledge of complex root canal configurations can lead to missed canals, failure to negotiate canal deviations, bifurcations, trifurcations, anastomoses, fins, and isthmuses, thereby complicating treatment. This case series focuses on the importance of diagnosis, radiographic interpretation, and treatment planning in managing maxillary first premolars and mandibular second premolars with aberrant canal anatomy.

INTRODUCTION

A comprehensive understanding of root canal anatomy and morphology is essential for successful endodontic treatment, particularly in cases involving teeth with complex anatomical variations, in maxillary first premolars and mandibular second premolars.[1] One of the important aspects pertaining to successful endodontic treatment is a thorough understanding of root canal anatomy and morphology, especially when dealing with teeth that exhibit complex anatomical variations, which is commonly encountered in mandibular second premolars and maxillary first premolars. During endodontic treatment, it might be especially difficult to locate and access root canals in premolars with unusual geometries. Preoperative two-dimensional (2D) radiographs sometimes fail to clearly reveal the presence of canal variations, and hence, the need for 3D imaging is pivotal.[1,2]

Conventionally, mandibular premolars have been considered to have a single root and single canal morphology; however, research has shown variations, such as multiple roots and canals in these teeth.[3] The presence of two or even three roots in mandibular second premolars, although rare, illustrates the intricate nature of their root canal system.[4] Extensive studies have documented anatomical variations in mandibular premolars, with foundational work by various researchers. These studies reveal that multiple canals are more prevalent in females with an incidence rate of 11% compared to males exhibiting 9%.[4,5,6]

The root canal morphology of maxillary premolars, particularly the first premolar, is predominantly characterized by the presence of two canals, with configurations ranging from Type II to Type VII according to Vertucci’s classification. However, the occurrence of three roots in a maxillary second premolar is rare, with only a few cases documented in the literature.[7] Pecora et al. discovered that there is a considerable variation in the root canal structure of maxillary first premolars, with 55.8% having a single root, 41.7% having two roots, and 2.5% having three roots.[4]

Usually, maxillary and mandibular premolars are treated based on the assumption that they exhibit only two and one canal. However, recent research has shown that up to 6% of maxillary first premolars may have three canals, emphasizing the necessity for thorough examination and precise diagnosis to ensure successful treatment outcomes. Three-rooted maxillary first premolar usually resembles a smaller, three-canaled maxillary molar.[5,6,7]

Historically, endodontic protocols relied on generalized anatomical models, potentially overlooking individual variations. However, advancements in imaging techniques, using cone-beam computed tomography (CBCT), have provided greater insight into the intricate nature of the root canal systems, facilitating more precise diagnosis and tailored treatment planning. Recent studies have revealed that anatomical variations in both mandibular and maxillary premolars are more prevalent than previously recognized, with a higher incidence observed in females.[5]

Successful management of complex cases requires precise diagnosis and tailored treatment strategies, as failure to address these complexities can lead to procedural errors and treatment failures. The current case series delves into the complex anatomy of the mandibular second premolars and maxillary first premolars, focusing on the challenges presented by their atypical root canal configurations. This detailed case series examines and manages mandibular second premolars with dual roots and maxillary first premolars with three separate roots and canals.

CASE REPORTS

Case 1

A 22-year-old female patient reported to the department of conservative dentistry and endodontics with a chief complaint of pain in the lower right back tooth region for the past 5 days. The patient had no contributory medical and surgical history. Pain was of intermittent type, aggravated on taking cold foods, and persisted even after the removal of stimulus. Intraoral examination revealed a deep carious lesion affecting the disto-occlusal surface of tooth no. 45. Pulp sensibility tests, cold (Miracold Plus, Hager Werken, Germany) and electric pulp test (Sybron Endo, Kerr, US), elicited an immediate response which was lingering in nature. Multiple digital periapical angled radiographs were taken (straight view and angled view (SLOB technique: 15°–20° mesially and distally) to discern extra roots or canals in tooth no. 45. Caries extended into the enamel, dentin, and pulp. Two distinct root outlines were seen, and the roots appeared narrower with individual periodontal ligament space surrounding each root, and these findings confirmed the presence of two roots, buccal and lingual. In the buccal root, the main canal trace disappeared at the coronal third, and it appeared off centered which was suggestive of a bifurcation. In the lingual root, no canal was observed [Figure 1a]. Evaluating the clinical signs, symptoms, pulp sensibility tests and radiographs a diagnosis of irreversible pulpitis, normal apical tissue was made.[8] The treatment plan involved root canal therapy, followed by partial coverage restoration.

Figure 1.

(a) Preoperative radiograph showing disto-occlusal caries in 45, (b) Working length radiograph depicting three canals, (c) Three separate exit of canals observed under magnification, (d) Master cone, (e) Postoperative obturation radiograph showing filled buccal root with a bifurcation at the middle third which is complete, (f) mesial angulation, (g) Distal angulation

Rubber dam isolation (Coltene, Switzerland) was done for tooth no. 45. With the aid of the dental operating microscope (DOM) (Labomed, US) at ×1.6 magnification, access preparation was done using an Endo Access Bur-Size 1, diameter 0.7 mm (Dentsply Maillefer, Switzerland). Access preparation was modified by extending it slightly buccolingually to ensure an unobstructed path to the orifices. On reaching the pulp chamber, DG16-1 (EXDG16) endodontic explorer (GDC Fine Crafted Dental Pvt. Ltd.) was used to explore hidden orifices. Once located, the orifices were enlarged using the controlled memory Nickel Titanium rotary file 25/.08, 19 mm (HyFlex™ CM) which was secured to the CanalPro CL2i Endomotor (Coltene, Switzerland). The speed and torque were set at 500 rpm and 2.5 N.cm. At ×2.5 magnification, the canals were observed to identify the bifurcation. A size 10 K file (Mani, Japan) was introduced into the buccal root, and resistance was felt at the middle third which confirmed a bifurcation from the main canal. Then, #6 and #8 K files (Mani, Japan) were used to negotiate the canals. Troughing of the buccal canal was done with ultrasonic tips (Dentsply Start-X #2). The bifurcation was debrided, using an ED18 ultrasonic tip (Woodpecker DTE D600). It was used in a back-and-forth motion without water for better visibility. The ED 18 tip was activated in dry mode for 5–10 seconds and paused for 2 seconds. This cycle was repeated and additionally the wet mode was turned on every 60 seconds for cooling and rinsing off the debri (as per manufacturer’s instructions). Then, a #10 K file was used and patency for both the main and bifurcating canal in the buccal root was achieved. A check X-ray with #10 files showed a separate exit of the main and the bifurcating canal in the buccal root and a single canal with a separate exit in the lingual root. Working length was confirmed using Ingle’s radiographic method in combination with an electronic apex locator (Morita Root ZX, Kyoto, Japan) [Figure 1b and c]. The canal configuration for tooth no. 45 – as per Vertucci’s root canal classification, the buccal root had a Type IV (1-2) one canal splitting into two and the lingual root had a Type I (1-1). As per Ahmed HMA’s root canal configuration classification system, it is described as (²45 B^1-2 L¹).[8,9] Glide path was achieved by precurving the HyFlex™ CM file 15/.04, 21 mm (Coltene, Switzerland). Shaping was performed at a speed and torque of 500 rpm and 2.5 N.cm using HyFlex™ CM 20/.04. A #10 K file was used in between the shaping phase, until the 20/.04 NiTi rotary instrument reached the full working length. The rotary NiTi files were activated only after placing them inside the canal, and care was taken not to force them into the bifurcating canal. To disinfect and prevent debris accumulation, copious irrigation was performed using 3% sodium hypochlorite (NaOCl) (Prime Dental Products, Thane, India). Irrigant activation using ultrasonic tips E60 (Woodpecker DTE D600) was done (2 min per canal). For smear layer removal, 17% ethylenediaminetetraacetic acid (EDTA) (Prime Dental Products, Thane, India) was used (1 min). Normal saline was used as the final rinse. Nonsetting calcium hydroxide (CaOH) dressing was placed for a week.

In the second appointment, the patient was asymptomatic. CaOH cement was removed using a #20/.02 H file (Mani, Japan), and canals were irrigated using 3% NaOCl. After confirming tug back with 20/.04 gutta-percha (GP) (Dentsply Maillefer, Switzerland), a check X-ray was taken [Figure 1d]. The canals were dried with sterile paper points, and obturation was completed using a hydrophilic single-cone technique with calcium silicate-based sealer (CeraSeal Bioceramic root canal sealer, Meta Biomed, Korea). Access cavity was restored with Smart Dentin Replacement (SDR) flowable bulk-filling composite (Dentsply Sirona, US), and a postobturation radiograph [Figure 1e-g] was taken, followed by CBCT to rule out missed canals and to confirm obturation of all roots and canals [Figures 2a-e]. Follow-up was done at 1, 3, 6, and 12 months, and the radiographs showed no evidence of periapical pathology.

Figure 2.

(a) Cone-beam computed tomography – Tooth #45 two distinct roots (buccal and lingual) separated buccolingually in sagittal and coronal view (d and e). Axial slices (a-c): Coronal third level canal appearing confluent, middle third level canal bifurcates which is visible on the axial slice as it moves apically (b) which denotes complete bifurcation in the buccal root, lingual root showing single canal from coronal to apical (c) apical third level showing two separate filled canal lumen in the buccal root terminus and one canal lumen in the lingual root terminus

Case 2

A 22-year-old female patient presented with pain in the lower left back tooth region. Clinical examination revealed a deep carious lesion affecting the disto-occlusal surface of tooth no. 35. Pulp sensibility tests, cold and electric pulp tests, elicited exaggerated response. Radiographic evaluation showed caries extending into the dentin and pulp, along with two distinct narrow roots in the mandibular second premolar [Figure 3a]. A diagnosis of irreversible pulpitis, normal apical tissue in tooth no. 35 was made.[8] The treatment plan involved root canal therapy, followed by a direct composite restoration. Under rubber dam isolation and at ×1.6 magnification, the access preparation was done, and the pulp chamber floor revealed two distinct canal orifices situated buccally and lingually. Orifice enlargement was done using the HyFlex™ CM NiTi rotary file 25/.08, 19 mm which was driven at 500 rpm and 2.5 N.cm. At × 2.5 magnification, the canals were observed, and the buccal root had one canal. However, the presence of a split and its exact origin from the main canal in the lingual root was inconclusive owing to limited higher magnification (>×6). Hence, the tactile method was carried out with a size 8 K file, and resistance was encountered at the middle third which confirmed the probability of a deep split. The working length was confirmed using a size 15 K file, 21 mm [Figure 3b]. The canal configuration for buccal root had a Vertucci’s Type I (1-1), and the lingual root had a Type III (1-2-1). As per Ahmed HMA’s root canal classification system, it will be described as (²35 B¹ L¹^–2–¹).[8,9] Glide path was achieved by precurving the HyFlex™ CM rotary file 15/.04, 21 mm. Shaping was performed at a speed and torque of 500 rpm and 2.5 N.cm using HyFlex™ CM 20/.04, 21 mm. A #10 K file was used in between the shaping phase, until the 20/.04 NiTi instrument reached the full working length (19 mm). The rotary files were activated only after placing them inside the canal. Copious irrigation was performed using 3% NaOCl. Irrigant activation using ultrasonic tips E60 was done (20 ml per canal for 2 min). For smear layer removal, 17% EDTA was used. Normal saline was used as the final rinse. 3D obturation was completed using a hydrophilic single-cone technique with calcium silicate-based sealer [Figure 3c]. The protocols armamentarium and techniques used for access preparation, orifice detection, shaping, cleaning and obturation in this case were the same, to those used in the previous case. The make and company of the equipment and materials used for performing this case were same as the previous case. Access cavity was restored with SDR flowable bulk-filling composite, and a postobturation radiograph was taken [Figure 3d-e]. CBCT was done to rule out missed canals and to confirm the obturation of all roots and canals [Figures 4a-e]. Follow-up was done at 1, 3, 6, and 12 months, and the radiographs showed no evidence of periapical pathology.

Figure 3.

(a) Preoperative radiograph showing disto-occlusal caries in 35, (b) Working length radiograph depicting two canals (c) Master cone, (d) Postoperative obturation radiograph showing the filled split originating from the middle third of the lingual canal, (e) distal angulation

Figure 4.

Cone beam computed tomography shows the Axial view (a-c) and Sagittal view (d and e) of two rooted mandibular premolar tooth no.35. Sagittal view (d and e) shows two distinct completely filled buccal and lingual roots. Axial view: Coronal third – the filled (radiopaque) canals appear confluent both buccally and lingually. Middle third – the filled canals appear to expand indicative of a split in the lingual canal. Apical third – two separate radiopacities are seen (buccally and lingually) suggestive of two canals as the lingual split merges at the apical third of the lingual canal

Case 3

A 40-year-old male presented with pain in the lower left back tooth region. Intraoral examination revealed a deep carious lesion affecting the occlusal surface of tooth no. 35. A slightly wider than the usual buccolingual dimension of the tooth crown was observed. The patient had no contributory medical and surgical history. Pulp sensibility tests, cold (Miracold Plus, Hager Werken, Germany) and electrical pulp tests (Sybron Endo, Kerr, US), elicited a delayed response. Radiographic analysis showed caries extending into the enamel, dentin, and pulp [Figure 5a]. Angled views (15°–20° mesial or distal shift) showed the presence of two roots superimposing each other but not completely. Curvature was observed in both buccal and lingual roots. The diagnosis was confirmed to be irreversible pulpitis, normal apical tissue in 35, after evaluating the clinical signs, symptoms, and radiographic evidence. The treatment plan involved root canal therapy, followed by composite restoration. Under rubber dam isolation (Coltene, Switzerland) and at × 1.6 magnification (Labomed, US) access opening was extended buccolingually, and it revealed two canal orifices, buccal and lingual. Troughing of the pulp chamber with ultrasonic tips #2 (Dentsply, Sirona Start-X) was employed to open up the orifices. The orifices were enlarged using NiTi rotary endodontic file SX 19/.04, 17 mm (Dentsply, Sirona ProTaper Gold, US) set at a speed and torque of 300 rpm 5.1 N.cm. Patency was achieved using a #10 K file (Mani, Japan). The patency file conformed to the direction of root curvature, and this direction was fixed by turning the teardrop of the silicone stopper toward it. This was reproduced to the #15 K file to negotiate the distal curvature for both the roots. A manual glide path was achieved using gentle negotiation with #10K–#15 K files. The working length was confirmed using the #15 K file (buccal: 17 mm and lingual: 18 mm) [Figure 5b]. The canal configuration comes under the Vertucci’s root canal configuration type I and Ahmed HMA’s root canal configuration classification (²35 B ¹ L ¹).[8,9] Shaping was done in the following sequence: S1 18/.02 300 rpm and 5.1 N.cm, S2 20/.04, F1 20/.07 300 rpm and 1.5 N.cm (length 21 mm). The protocol used for disinfection and 3D obturation was the same as the previous case [Figure 5c]. Access cavity was restored with SDR flowable bulk-filling composite, and a postobturation radiograph was taken [Figure 5d]. Follow-up was done at 1, 3, and 6 months, and the radiographs showed no evidence of periapical pathology.

Figure 5.

(a) Preoperative radiograph showing occlusal caries in 35 – showing two distinct roots (buccal and lingual), (b) Working length radiograph depicting two roots and one canal in each root, (c) Master cone, (d) Postoperative radiograph showing two separate filled canals

Case 4

A 22-year-old female patient presented with pain in the upper left back tooth region. Clinical examination revealed deep caries in tooth no. 24, involving the pulp. The tooth was tender to percussion test. Pulp sensibility tests (cold and electrical pulp tests) elicited an exaggerated response which was lingering in nature. Radiographic evaluation indicated an abrupt loss of continuity of radiolucency in the canals suggesting a possible root canal variation [Figure 6a]. The mesiodistal width of the roots was observed to be greater than that of the crown which was suggestive of extra roots or canals.[4,10] The diagnosis was confirmed to be irreversible pulpitis, symptomatic apical periodontitis in 24, after evaluating the clinical signs, symptoms, and radiographic evidence. Access cavity was prepared extending mesiodistally through the buccal aspect to expose all orifices – T-shaped access outline from the usual ovoid shape. The pulp chamber floor comprised one mesiobuccal (MB), one distobuccal (DB), and one palatal (P) canal orifices. The orifices were enlarged using NiTi rotary endodontic file SX 19/.04, 17 mm (Dentsply, Sirona ProTaper Gold, US) at a speed and torque of 300 rpm and 5.1 N.cm. The working length of the canals was confirmed with radiographs and electronic apex locator (MB, DB – 18 mm and P – 19.5 mm) [Figure 6b]. The canal configuration comes under the Vertucci’s root canal configuration type VIII and Ahmed HMA’s root canal configuration classification (³24 MB ¹ DB ¹ P ¹).[8,9] Shaping of the canals was in the following sequence: S1 18/.02 300 rpm and 5.1 N.cm, S2 20/.04, F1 20/.07 300 rpm and 1.5 N.cm (length: 21 mm). The disinfection and 3D obturation were the same as that of the previous case [Figure 6c]. The access cavity was restored with SDR flowable bulk-filling composite, and a postobturation radiograph was taken [Figures 6d-e and 7a-e]. CBCT was done to assess any missed canal, the filling and sealing quality of all roots and canals. Follow-up was done at 1, 3, 6, and 12 months, and the radiographs showed no evidence of periapical pathology.

Figure 6.

(a) Preoperative radiograph shows radiolucency disto-proximally (dental caries) involving enamel dentin and pulp in tooth no.24. Two distinct root outlines seen with no evident periapical radiolucency. (b) Working length (SLOB rule) - three distinct root outlines and files seen in all three canals, which confirms presence of Mesiobuccal, Distobuccal and Palatal roots. (c) Mastercone- Gutta percha well adapted to full working length for all three canals observed. (d and e) Post operative radiograph shows homogenous radiopacity in all three root canals with adequate coronal seal

Figure 7.

Cone beam computed tomography shows the Axial view (a-c), Coronal view (d) and Sagittal view (e) of three rooted maxillary premolar tooth no.24. Sagittal view (d) shows filled buccal and palatal roots. Axial view: Coronal third – the canals appear to merge due to the filling material, Middle third – the filled mesiobuccal and distobuccal canals appear closer to each other and a filled palatal canal seen, Apical third – clearly reveals three separate radiopacities (two buccally and one palatally) confirming the presence of three roots and canals

DISCUSSION

Effective endodontic treatment relies on understanding and managing complex root canal anatomy. Accurate sealing of all portals of entry is crucial for preventing reinfection, especially in teeth with unusual root canal configurations.[11] This discussion highlights key considerations for the management of mandibular second premolars and maxillary first premolars with atypical root canal system.

The mandibular second premolars occasionally present with two roots and three canals, a rare occurrence with an incidence of <0.5%. Studies by Zilich et al. and Sert[12,13] confirm these variations, with 0.4% of mandibular second premolars having three canals. Sert and Bayirli reported a minimal incidence of three root canals.[13] The occurrence of three canals in mandibular second premolars has been reported to be 0%–0.4%. The maxillary first premolar typically has two roots and two canals, but variations, including three roots and three canals,[14,15] have been documented. Kartal (1996) found that while these variations are rare, they do occur in a small percentage of cases. Identifying these configurations can be challenging with standard radiographs, which may not clearly reveal the complexity of the canal system. Changes in radiographic density or abrupt narrowing of the pulp space often indicate the presence of additional canals or bifurcations.[11]

The mandibular premolars with aberrant root canal configuration can pose diagnostic and procedural challenges to the clinician. Therefore, a thorough clinical, diagnostic, carefully tailored treatment design and armamentarium is critical. Failure to identify extra canals, bifurcations, and splits can render endodontic therapy a failure. Identifying the number of roots and canals and a thorough knowledge of the biology and the anatomy of such teeth, determined by careful radiographic assessment and 3D imaging, could contribute to successful and predictable endodontic outcome. Other diagnostic tests such as the Redline, White line, Champagne bubble, and dyes also guide the clinician to identify missing root canal orifices.[5,12,13,16]

Superimposition of the 2D periapical radiograph can be sometimes misleading. To counteract these challenges, multiple angled periapical radiographs (straight, mesial, and distal shifts) were exposed to identify extra canals and roots (SLOB technique) in this case series. The bifurcation and the deep split in tooth nos. 45 and 35 (cases 1 and 2) were inconclusive in the X-rays. However, a sudden fast break in the main canals of these teeth prepared the operator to expect a bifurcation or a split. Missing a bifurcation and split in the middle third could have been a possibility in cases 1 and 2 as it was very difficult to identify it in the preoperative periapical radiographs. Splits generally curve sharply or branch oblique and have steep angles which were encountered in case 2.

CBCT (3D digital imaging) is crucial as it offers multiplanar reconstruction in axial, coronal, and sagittal views. Axial slices can be scrolled from the coronal to the apical third and can significantly detect and localize canal lumens that appear as dark-, round-, or oval-shaped radiolucent areas.[17] Axial slices can also identify the course of canal lumen, the number of lumens present and if they are separate or united. The sagittal view helps identify the vertical canal course and at what level the split begins. The coronal view assesses the vertical entry point of canals and reveals the starting point of the split (coronal or middle or apical third).[18,19,20]

All procedures were performed under ×1.6–×2.5 magnification (DOM) for enhanced vision and unwarranted removal of the healthy tooth substrate. Access cavity margins were extended more buccolingually from the standard ovoid outline for lower mandibular premolars to avoid missing canals, especially the lingual in cases 1, 2, and 3. For case 4 (tooth no. 24), periapical radiographic evaluation indicated an abrupt loss of continuity of radiolucency in the canals suggesting a possible root canal variation [Figure 6a]. The mesiodistal width of the roots was observed to be greater than that of the crown which was suggestive of extra roots or canals.[4,10] The cavity design was modified from the usual buccolingual extension to a T-shaped access outline by extending it mesiodistally (buccal aspect) to allow access to the MB and DB canals.[21] Long shank burs or surgical length burs or ultrasonic tips can be used for better visibility and controlled refinement of the access; in our case, ultrasonics were adopted. Orifice enlargement was done using HyFlex™ CM rotary files to avoid stripping. At ×2.5 magnification tooth no. 45 (case 1) exhibited a clear division point where the main canal forked at the middle third within the buccal root. However, a ×2.5 magnification was not adequate to visualize a split as deep as a mid-root level in tooth no. 35 (Case 2). However, a hazy narrow isthmus was seen at the mid-root level confirming a split in the lingual canal. Hence, a tactile method was used to confirm the split using finer hand file #10 K file (resistance at the coronal third and middle third of the buccal and lingual roots of tooth nos. 45 and 35 was felt). K files #6, 8, and 10 were used to scout and negotiate the split using watch-winding motion to achieve the initial manual glide path. 17% EDTA was used minimally to ensure the files did not bind to the bifurcation and the split.

File deviation and ledge formation are most commonly encountered when there is a bifurcation or split.[22] Hence, the canals in cases 1 and 2 were carefully troughed using ultrasonic tips activated in dry mode 5–10 s for better visibility, then paused for 2 s and water activated every 60 s to cool and rinse. The rotary glide path file HyFlex CM was pre-bent to navigate the slender canals as these files exhibit high flexibility, controlled memory, high cyclic resistance, canal-centering ability, and least apical transportation in curvatures.[23] For case 1, the canals in the buccal root were shaped separately as the bifurcation was complete. Minimal taper rotary files were used to prevent over flaring these thin roots. The splitting canal was not instrumented using rotary files to prevent ledge or transportation in tooth no. 35 (case 2). Once the finer hand files became loose in the split canal, copious NaOCl activation using ultrasonics was done to facilitate irrigant penetration to clean the space efficiently. For tooth no. 35 (case 3), the buccal and lingual canal curvatures were negotiated with finer-sized hand files, and then, the subsequent-sized hand files were prebent to minimize canal straightening. When resistance was felt, the files were withdrawn prebent and instrumented using the watch-winding motion. The crown-down technique was used for all cases to minimize torsional stress.

The recommended disinfection protocol for managing complex anatomies includes the use of 3%–5.25% NaOCl and 17% EDTA. Techniques such as passive ultrasonic irrigation (PUI), sonic activation, and apical negative pressure irrigation have shown to enhance disinfection and disrupt biofilm in apical areas, bifurcations, and lateral ramifications. Using a small, side-vented irrigation, needle improves the flow of irrigants, while intracanal medicament, such as CaOH, is typically applied for 1 week to further aid in disinfection.[24] In this case series, a combination of EDTA and PUI using NaOCl was employed to maximize debridement of bifurcation and hidden splits.

The standardized filling protocols include the use of thermoplasticized injectable GP technique, squirt technique, and alternatively, the hydrophilic single-cone obturation technique. The thermoplasticized injectable GP technique involves injecting a heated, softened GP into the canal to fill and seal it. In the squirt technique, both ends of the root canals are obturated simultaneously with thermoplasticized GP, followed by backfilling, which has shown to be particularly effective. The hydrophilic single-cone obturation technique involves using a solid core GP and a calcium silicate-based sealer which was used in this case series.[24] Bioceramic sealers are particularly advantageous due to their bioactivity, dimensional stability and their ability to flow into bifurcations, canal splits, fins, lateral canals, and curved canals. Flow is an essential property that allows a sealer to fill difficult-to-access areas, such as the narrow irregularities of the dentin, isthmus, and accessory canals.[25] In this case series, a hydrophilic single-cone technique with calcium silicate-based sealer was done to ensure the sealer penetrates sufficiently into these intricate areas where the plasticized solid core obturation material (GP) cannot flow.

To ensure that all the roots, main or additional canals, bifurcations and splits were identified and filled, the patients were subjected to CBCT after treatment. CBCT axial (cervical, middle, and apical), sagittal, and coronal views confirmed dense obturation of all the main canals, additional canals, bifurcation, and split for mandibular premolars (tooth nos. 45 and 35). In tooth no. 24, all the three roots and canals appeared radio-opaque from coronal to apical third. Identifying anatomical variations by employing advanced diagnostic tools, can best prepare the operator, to minimise the risk of procedural errors and reinfection that are most commonly encountered while treating unusual root canal anatomy.

CONCLUSION

Expecting a routine root canal anatomy should not be a fixed mindset of the clinician. Instead, one should be prepared for an unexpected reroute from the main canal. The prognosis of endodontic therapy in teeth with aberrant root canal configuration depends on several factors such as, a thorough understanding of racial variations in root canal anatomy, careful interpretation of angled radiographs and 3D CBCT images, an accurate diagnosis, the use of magnification tools and the clinician’s level of expertise.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.