Endodontic management of a mandibular second premolar with perforating internal resorption by using MTA and cone beam computed tomography as a diagnostic aid
A 54-year-old woman reported to the dental office with pain and swelling in the right mandibular posterior region. The medical history was non-contributory. She had no history of traumatic injury or orthodontic treatment. Clinical examination showed small intraoral swelling with relation to 45. The tooth was slightly tender to percussion and served as an abutment to a long span bridge extending upto 48. The probing depths were within normal limits.\nIntraoral periapical radiographic examination revealed a well-circumscribed, fairly round radiolucency in the cervical third of the root with diffuse periapical rarefaction []. Clinical symptoms and radiographic examination suggested a diagnosis of internal resorption and pulp necrosis. The Bridge was cut and removed to preserve the integrity of tooth with resorption and endodontic treatment was scheduled. It was decided not to include 44 as the patient was reluctant to sacrifice a healthy tooth and was ready to wear a partial denture in case of future loss of tooth. Implant was not considered due to financial constraint of the patient. As the conventional intraoral radiographs do not indicate the true size and spread of the lesion, the patient was sent for CBCT to evaluate the true size and nature of the lesion. Informed consent was obtained from the patient and a CBCT imaging of the mandible was performed by using the CBCT scanner (CS 9300 3D Digital Imaging System, Hatfield, PA). The involved tooth was focused, and the morphology was obtained in axial sections of 90 μm thickness with 300 μm spacing. The CBCT images revealed well-circumscribed radiolucent area with relation to 45 below the level of cemento-enamel junction, involving the distal wall of the root and extend apically upto the middle of the root length suggestive of perforating internal resorption [].\nBased on above finding, root canal therapy was initiated. The tooth was isolated under rubber dam (Hygienic Dental Dam, Coltene Whaledent, Germany) and accessed without anesthesia. The necrosed pulp tissue was removed. Presence of hemorrhagic fluid in the canal suggested of a small communication between the resorptive defect and the lateral periodontium. Working length determination was established using apex locator (Root ZX II; Morita, Tokyo, Japan) and radiography []. The canal was prepared using crown down technique with ProTaper files (Dentsply, Tulsa dental specialities, Ballaigues, Swizterland) accompanied by copious irrigation with 2.5% sodium hypochlorite (Dentpro, Chandigarh, India). A calcium hydroxide paste dressing (Metapex; Meta Biomed Ltd, Choenju city, Chungbuk, Korea) was placed to alkalinize the environment and control bleeding at the perforation. The calcium hydroxide dressing was changed twice every 15 days. Master cone radiograph was taken [] and the canal below the resorptive defect was obturated with gutta percha (Dentsply, Maillefer) and AH Plus sealer (Dentsply, Maillefer, Konstanz, Germany) using a combination of cold lateral condensation and vertical compaction with heated pluggers and condensers. The resorptive defect and the remaining canal were then condensed with MTA (Proroot MTA, Maillefer, Dentsply, Swizterland), using MTA carrier and root canal pluggers [] (Dentsply, Maillefer). Since the perforation was very small it was decided not to place a matrix. A wet cotton pellet was placed on this and the access was temporarily sealed with MD Temp (Meta Biomed Ltd, Choenju city, Chungbuk, Korea). An immediate postoperative radiograph was taken to confirm a satisfactory filling of the resorptive defect []. Fourty-eight hrs later after checking the set of MTA the access cavity was finally sealed with light cure composite resin (Tetric Ceram, Ivoclare, and Vivadent). Finally, porcelain fused to metal fixed partial denture was placed after 4 weeks.\nThe patient was recalled after 3 months and 6 months and the tooth was found to be symptom-free with healthy gingiva. The periapical radiographs also showed satisfactory healing of the apical rarefaction and also formation of a calcific barrier between the perforation and lateral periodontium []. This was further confirmed with 6 month follow up CBCT scan [].