Radicectomy of radix entomolaris: An alternative treatment approach for persistent periapical lesion assisted by cone-beam computed tomography and operating microscope.

Every clinician as well as patient would prefer to sustain their natural teeth in all situations. For a badly mutilated terminal abutment, molar treatment options are limited, but loss of posterior tooth can lead to several unwanted sequelae. A guiding principle should be to preserve what is present. If complete preservation is not possible, the most conservative treatment should follow in every clinical situation. Radisectomy is one such conservative surgical treatment approach that allows resection of one or more affected roots of tooth at the level of furcation and preserves the remaining roots and the complete crown structure, thereby maintaining the occlusal harmony. Hereby, we are presenting a case report on radicectomy of distobuccal root of a mandibular third molar with persistent periradicular pathosis, with the assistance of microscope and cone-beam computed tomography. Copyright:

INTRODUCTION

Maintaining a functional dentition for lifetime has been a dream for patient as well as dentist since ages. Recent advances in dentistry provide an opportunity for patients to maintain their functional dentition.[12] Loss of a terminal abutment tooth can lead to unwanted sequelae such as displacement of teeth, collapsed bite, supra-eruption of antagonist, loss of supportive alveolar bone, and decrease in the chewing ability.[3] An endodontically treated tooth with persistent periradicular pathology is routinely managed by nonsurgical retreatment.[4] However, in some situations, wherein if successful nonsurgical retreatment is not attainable or its prognosis is considered to be questionable, then surgical treatment might be unavoidable. Various surgical treatment options available are 1. Traditional periapical surgery including curettage and apicectomy of the diseased root followed by retrograde filling; 2. Radisectomy of diseased root; 3. Hemisection of the crown along with the diseased root; 4. Extraction followed by implant, in the increasing order of surgical destruction of a tooth.[456] If complete preservation of tooth is not possible, then the most conservative treatment approach should follow in every clinical situation. Radicectomy is the process of resecting one or more roots of a tooth at the level of furcation while preserving the crown and the remaining roots in function.[7] Hence, radicectomy procedure is a valuable treatment approach in conserving the remaining natural tooth structure and its occlusal harmony.

Hereby, we are presenting a case report of radicectomy of distobuccal root of mandibular third molar with radix entomolaris which is characterized by the presence of an extra root on distolingual side. The entire procedure was done under dental operating microscope for adequate illumination and magnification[8] and with the guidance of cone-beam computed tomography (CBCT) as it provides high-quality and accurate images three dimensionally for osseous elements.[9]

CASE REPORT

A 24-year-old male patient reported to the department of endodontics with a complaint of pus drainage in his right lower back tooth region for 10 days. The patient gave a history of extraction of mandibular right second molar 10 years back as it was grossly decayed in a private dental practice. One year back, root canal treatment was initiated in mandibular right third molar in a private dental practice, which was not completed. On clinical examination, mandibular third molar (#48) was drifted mesially into the position of mandibular second molar (#47) and temporary cement was evident though it was not intact. The gingiva on buccal side of the tooth showed sinus tract. The overlying mucosa of the sinus tract was red and shiny with a discharging fistula [Figure 1a]. Intraoral periapical radiograph (size 2 and E speed film, Kodak, Carestream, India) of #48 suggested that this was a case of radix entomolaris having 3 roots (1 mesial, 1 distobuccal, and 1 distolingual roots). Radiograph showed well-defined radiopacity in the coronal area suggestive of temporary material and loss of lamina dura with periapical radiolucency of size more than 1 cm in diameter at the distal roots of #48 and external resorption was evident in distobuccal root and sinus tract was tracked to periapical radiolucency [Figure 1b]. Provisional diagnosis was made as nonspecific inflammatory periapical cyst as there is a sinus tract with purulent discharge and treatment plan was continuation of nonsurgical endodontic treatment.

Figure 1

Step-wise procedure of nonsurgical root canal treatment: (a) Preoperative clinical photograph along with sinus tracing; (b) Preoperative periapical radiograph along with sinus tracing; (c) Access cavity showing four canals; (d) Irrigating solution from distobuccal canal coming through fistula; (e) Radiographic working length determination; (f) Healing of the sinus tract; (g and h) Obturation; (i) Sinus recurrence after postendodontic restoration; (j) Preoperative panoramic view showing proximity of vital elements; (k and l) Panoramic, axial, and cross-sectional view showing size of the lesion before radicectomy respectively; (i) 6-month postoperative clinical picture

Access cavity was refined under dental operating microscope (Carl Zeiss Surgical GmbH, Germany). Four canals were evident – mesiobuccal, mesiolingual, distobuccal, and distolingual canals [Figure 1c]. While performing the treatment, direct connection of the sinus to the distobuccal canal was clearly evident as the irrigating solution from the distobuccal canal was draining from the discharging fistula [Figure 1d]. Working length, approximately 0.5 mm from the apical foramen, was determined with apex locator (Root ZX, Morita, Tokyo, Japan) for each canal and finalized with the help of radiograph [Figure 1e]. Initial apical file sizes were corresponding to 15 no. K-file in all the canals except distobuccal canal for which it was 25 no. K-file. Cleaning and shaping was done with crown down technique using ProTaper files (Dentsply, Maillefer, Switzerland) till F3 as master apical file in mesiobuccal, mesiolingual, and distolingual canals whereas F5 in distobuccal canal. Irrigation was done with 3% sodium hypochlorite (Prime Dental Products, Thane) during biomechanical preparation. Calcium hydroxide paste (Prime Dental Products, Thane) was condensed with paper points till the full working length as it creates favorable environment for healing and osseous repair in the presence of large periapical lesion along with its antimicrobial activity.[10] Access was sealed with glass-ionomer cement (GC, Tokyo, Japan), and the patient was recalled after 15 days. As the distobuccal canal presented the exudate at recalls, calcium hydroxide medicament paste was replaced every 15 days over a period of 3 months. After 3 months, the canals were completely dried and sinus tract was healed [Figure 1f]. Final irrigation was done with 1 ml of 17% ethylenediaminetetraacetic acid (Desmear, Anabond, India) in each canal, and the canals were dried with paper points and obturated with corresponding ProTaper gutta-percha (Dentsply, Maillefer, Switzerland) using Endoseal MTA sealer (Maruchi, South Korea) [Figure 1g and h]. Ten days after obturation, postendodontic restoration was done with composite (Tetric N Ceram, Ivoclar, Vivadent). One month after postendodontic restoration, re-occurrence of the sinus tract was observed. Sinus tract was again traced to the previously traced point [Figure 1i]. Hence, surgical intervention was planned. CBCT (SOREDEX, CRANEX 3D, Finland) with small field of view (5 cm × 5 cm) was made for better understanding of the anatomy of the lesion and its adjacent vital elements. CBCT image evidenced that size of periapical lesion was 16.21 mm × 11.21 mm × 9.59 mm, proximity to the mandibular canal is 2.04 mm from the distobuccal root, and the periapical lesion was in very close proximity to the mandibular canal [Figure 1j-l]. Various treatment options such as curettage, apicectomy followed by retrograde filling, radicectomy of diseased root, hemisection and extraction, along with their benefits and complications were explained to the patient radicectomy was planned. The decision on which root needed resection was arrived based on the root that was affected, i.e., distobuccal root. The patient's consent was obtained. The medical and blood investigations (complete blood count, computed tomography, BT, hepatitis B surface antigen, and HIV tests) of the patient were found to be satisfactory for surgery.

Surgical site was cleaned with antimicrobial lotion (Povidone-Iodine, Win-Medicare Pvt. Ltd, India). Magnification was provided by dental operating microscope (Carl Zeiss Surgical GmbH, Germany). A triangular flap design which one horizontal sulcular incision and one vertical incision distal to tooth 46 were given with 15c scalpel and full-thickness mucoperiosteal flap was elevated and radicectomy of the distobuccal root was done 2 mm apical to the cementoenamel junction using a surgical length fissure bur (#702, SS White, India) with slow speed handpiece under copious saline irrigation [Figure 2a-c] under magnification. Curettage of the periapical tissue was done with microsurgical curette and it was sent for histological evaluation. After achieving a good hemostasis, GIC was placed in the prepared retrograde cavity after root resection using retro-plugger and with the help of micromirror for proper sealing. Platelet-rich fibrin (PRF) was prepared by centrifugation of 10 ml of the patient's venous blood at 1300 rpm for 14 min in centrifugation machine (A-PRF™ 12) and sheared the PRF plug from red blood cell and placed the PRF in the resected socket [Figure 2d]. Flap was approximated and sutured with black 3-0 silk sutures using micro-needle holder. Histological evaluation confirmed the diagnosis, i.e., nonspecific inflammatory periapical cyst [Figure 2e]. On 1-month follow-up, tooth was asymptomatic and sinus tract was healed completely. After 6-month follow-up, periapical healing was observed radiographically as there was a decrease in the lesion size and appearance of trabecular pattern [Figure 2f]. Clinically, tooth showed normal response to percussion and palpation. One-year follow-up showed improved radiographic findings with improved trabeculation [Figure 2g] and CBCT showed regression in the size of periapical lesion size from 16.21 mm × 11.21 mm × 9.59 mm to 14.92 mm × 9.22 mm × 7.90 mm [Figure 2h-j] Definitive restoration was done with Porcelain fused metal (PFM) crown [Figure 2k and l].

Figure 2

Stepwise procedure of radicectomy and follow-up images: (a) Radicectomy of distobuccal root; (b) Resected root and curetted tissue; (c) Immediate postoperative radiograph after radicectomy of distobuccal root; (d) Platelet-rich fibrin; (e) Histological picture; (f) 6-month follow-up radiograph; (g) 1-year follow-up radiograph; (h-j) Panoramic, axial, cross-sectional view showing decrease in the size of lesion at 1-year follow-up after radicectomy (k and l) Porcelain fused metal crown showing labial view and occlusal view respectively

DISCUSSION

The main aim of root resection in this case report was to remove diseased root which causes persistent periapical infection which cannot be subsided by endodontic treatment alone. Although the tooth was third molar, clinically and functionally it was serving the purpose of a mandibular second molar, thereby having a higher strategic value of tooth. Radicectomy procedure was first developed by Farrar for treating the furcation cases and most often used in maxillary molars having three roots.[11] In this case, we performed radicectomy for mandibular molar as it was a radix entomolaris having two distal roots. Other treatment options available are periapical curettage, apicectomy followed by retrograde filling, radicectomy of diseased root, and hemisection.[45] Curettage and apicectomy were not preferred in this case as these treatment options could not remove the contents of the periapical tissue in inter-radicular area of multirooted tooth. Hemisection involves removal of the crown structure along with the corresponding root and interferes with the occlusal harmony. Radicectomy of the distobuccal root was planned in this case as other roots were normal with acceptable periodontal support[12] and the tooth is having two roots on distal side and resection of one root at the level of furcation does not interfere with the occlusal harmony. PRF was placed in the resected socket as it was proved as an enhancer for soft- and hard-tissue healing.[13] Presurgical evaluation of the case was done using CBCT (SOREDEX-CRANEX 3D, Finland). It is a very good tool for better understanding of the lesion and it provides high-quality and accurate three-dimensional representation of the lesion and its proximity to the vital elements.[9] Dental operating microscope was used throughout the procedure as it provides adequate illumination and magnification.[8] Survival rate of this procedure has been varied with number of factors including case selection, periodontal support, and root selection. The overall survival rate of root-resected molars is 91.7%.[14] Success has been found to be good in this case at 1-year follow-up period as the patient was asymptomatic with no sinus tract, no mobility, and decreased lesion size (16.21 mm × 11.21 mm × 9.59 mm–14.92 mm × 9.22 mm × 7.90 mm). Long-term evaluation will give a better idea regarding the overall success of the procedure, and the case is under follow-up.

CONCLUSION

Radicectomy of diseased root followed by placement of PRF, in radix entomolaris with persistent periradicular pathosis, assisted by modern gadgets such as CBCT and operating microscope is a promising way for optimal healing of the periradicular tissues and to maintain its functions where other possible ways of treatment would not be feasible.

Declaration of patient consent

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

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.