Management of External Inflammatory Root Resorption Using Non-Surgical Endodontic Treatment with Mineral Trioxide Aggregate: A Case Report

Informed consent was acquired from the patient, following which root canal treatment was initiated for tooth #16 under local anesthesia using 2% lidocaine with 1:80,000 epinephrine (La-Force, Vishal, India). Access was gained using an Endo access bur (Dentsply Maillefer, Ballaigues, Switzerland) mounted on a high-speed handpiece, and the cavity was refined with an Endo-Z bur (Dentsply Maillefer, Ballaigues, Switzerland). Four canal orifices-mesiobuccal 1, mesiobuccal 2, distobuccal, and palatal-were located (Figure 1B). The palatal root showed signs of a wide open apex, prompting referral for a CBCT scan. The CBCT revealed a chronic periapical abscess and external root resorption associated with the palatal root of tooth #16 (Figure 2). Consequently, an apexification procedure was planned for the palatal root, followed by obturation and placement of a full-coverage crown.

Root canal treatment was continued for tooth #16. Working length determination was done using K-files (Mani Inc., Tochigi-Ken, Japan) and an electronic apex locator (Eighteeth E-pex, Changzhou, China), and later confirmed radiographically (RVG). Radiographic working length verification was done using Ingle’s method, and Weine’s modification was applied for the palatal canal, wherein 2 mm was subtracted from the radiographic apex (Figure 1C).^2,3 Biomechanical preparation was performed using nickel-titanium rotary files. The mesiobuccal-1 and mesiobuccal-2 canals were instrumented up to ProTaper Gold F1, and the distobuccal canal was enlarged up to Protaper Gold F2 (Dentsply Maillefer, Ballaigues, Switzerland), with intermittent irrigation using 3% sodium hypochlorite (Prime Dental Products Pvt. Ltd., Thane, Maharashtra) and normal saline. The palatal canal was instrumented with a No. 70 K-file (Mani Inc., Tochigi-Ken, Japan) (Figure 1D) and irrigated with 2% chlorhexidine gluconate (Waldent, India) followed by normal saline. A calcium hydroxide intracanal medicament (RC Cal, Prime Dental Products Pvt. Ltd., Thane, Maharashtra) was placed and the access cavity was sealed with Cavit (3M ESPE, Seefeld, Germany). The dressing was maintained for two weeks, with replacement at one-week intervals.

After two weeks, the patient was asymptomatic, and radiographic evaluation revealed a reduction in the size of the periapical lesion. Apexification of the palatal root was performed using MTA (ProRoot MTA White, Dentsply Sirona, Ballaigues, Switzerland) (Figure 1E). The MTA was condensed using a hand plugger RCP60 (GDC, India) and micro-applicator tips moistened with normal saline. Radiographs were taken intermittently to verify proper apical positioning of MTA. A moist cotton pellet was placed over the MTA, and the access cavity was sealed temporarily with Cavit (3M ESPE, Seefeld, Germany). The patient was recalled after two days, at which time an apical stop (seal) was confirmed using a No. 70 K-file (Figure 1F). The MB-1, MB-2, and DB canals were re-instrumented to the last used files and irrigated with 3% sodium hypochlorite (Prime Dental Products Pvt. Ltd., Thane, Maharashtra) followed by normal saline. The palatal canal was re-instrumented using a No. 70 K-file and irrigated with 2% chlorhexidine gluconate (Waldent, India) and normal saline. All canals were then dried with sterile paper points (Meta Biomed, Cheongju, South Korea). Obturation of the MB-1, MB-2, and DB canals was performed using the single cone gutta-percha points (Meta Biomed, Cheongju, South Korea) and AH plus sealer (Dentsply Maillefer, Ballaigues, Switzerland) (Figure 1G). The palatal canal was obturated using the cold lateral condensation technique. Post-endodontic restoration was completed with Miracle Mix (GC Fuji, Japan) (Figure 1G).

At the one-month follow-up, the patient remained completely asymptomatic. Radiographic evaluation revealed satisfactory bone healing, evidenced by a marked reduction in the periapical radiolucency. A full-coverage porcelain-fused-to-metal (PFM) crown was planned and subsequently placed on tooth #16 during this period (Figure 1H).

Discussion

EIRR is the most prevalent form of external root resorption and typically remains asymptomatic.^4,5 The resorptive process is initiated by an inflammatory response caused by the bacteria and/or their endotoxins reaching the periradicular space. Although EIRR most commonly affects the apical region of the tooth, it can occur at any level along the length of the root due to the presence of accessory or lateral canals, which can serve as alternate pathways for bacterial dissemination.^1,6 MTA was introduced in 1993 by Torabinejad et al. as a root-end filling material, owing to its superior sealing ability as compared with the then widely used amalgam. It also overcame the inherent drawbacks of amalgam, such as initial leakage, secondary corrosion, mercury and tin contamination, need for mechanical retention in the root-end preparations, staining of hard and soft tissues.⁷ Unlike amalgam, MTA does not require maintenance of a dry field; in fact, the requirement of moisture for its hardening further contributes to its success as a root-end filling material. Since its introduction, MTA has been widely used with success in procedures like pulp capping, apexification, root-end filling (both orthograde and retrograde), and the repair of perforations.^7-9

In the present case, resorption of the palatal root and the presence of a wide open apex limited the use of nickel-titanium rotary files; therefore, No. 70 K-file was used for the biomechanical preparation. Also, due to the potential cytotoxic effects of sodium hypochlorite when extruded beyond the apex, it was not used for irrigation of the palatal canal. Instead, 2% chlorhexidine gluconate was employed as an irrigant due to its superior biocompatibility compared with sodium hypochlorite.^10,11

At the one-month follow-up, the patient remained asymptomatic, and radiographic evaluation demonstrated satisfactory bone healing. Consequently, a full-coverage PFM crown was placed on the treated tooth. The rapid periradicular healing observed can be attributed to the osteoinductive potential of MTA when used as an apical filling material.¹²

At the six-month and one-year follow-up appointments, the patient continued to be asymptomatic, and radiographic evaluation revealed almost complete reduction of the periradicular radiolucency (Figure 1).

External inflammatory root resorption, if left untreated, can lead to significant loss of tooth structure and compromise the long-term prognosis. Accurate diagnosis, followed by conventional non-surgical root canal therapy utilizing an appropriate irrigation protocol, intermediate calcium hydroxide dressings, and MTA as an apical barrier material, can effectively arrest the resorptive process and promote periradicular healing, thus providing an overall successful clinical outcome in the management of EIRR cases.

Conflict of interest

None

Source of funding

Nil