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Retrieval of from the root canal space Iris Slutzky-Goldberg, DMD1/Joshua Moshonov, DMD2

Removal of foreign objects from the root canal can be very frustrating. The use of a variety of instruments and techniques has been suggested for the retrieval of obstacles from root canals during endodontic treatment. This article describes a method for retrieving a large mass of amalgam restoration that was wedged into the root canal. The amalgam, which had served as the provisional restorative material during apexification of an immature ante- rior tooth, was inadvertently pushed into the root canal. After the mass was bypassed, the amalgam was loosened with the aid of copious irrigation, chelation, and flotation. Hedstrom files twisted around the object allowed sufficient grip for its retrieval, enabling completion of the . (Quintessence Int 2006;37:318–321)

Key words: amalgam, bypass, chelation, foreign object, retrieval, root canal

Removal of foreign objects from the root obstructing object cannot be grasped, since canal is a complicated procedure. Fractured by so doing there is a possibility to loosen posts, points, and separated instru- and retrieve the object.3 ments are the main obstructions found, and Reamers and files should be used to these must either be removed from the root bypass the object, and solvents can be canal without changing the canal’s morphol- applied to loosen its cementation.4 Alterna- ogy or be bypassed.1 Careful instrumenta- tively, after the object is bypassed, two or tion, irrigation, and flotation are used to three Hedstrom files can be used alongside remove these obstructions.2 the bypassed instrument and twisted around According to the literature, a variety of it, so as to provide a sufficient grip for its instruments and techniques facilitate the retrieval.3,5 removal or bypass of an obstructing object in Use of ultrasonic devices may be helpful the root canal. Friedman suggested that in dislodging and loosening the foreign bypassing should always be attempted if the object from the canal walls, allowing flotation of the object.6–9 An additional technique for retrieving foreign objects from the root canal is the use of the Endo-Extractor System (Micromega) to grasp them. However, this 1Clinical Instructor, Department of , Hebrew technique is more suitable for anterior teeth University, Hadassah School of Dental Medicine, Jerusalem, Israel. and may involve the sacrifice of a consider- 1 2Clinical Senior Lecturer, Department of Endodontics, Hebrew able amount of radicular dentin, rendering it University, Hadassah School of Dental Medicine, Jerusalem, unsuitable for the apical portion of the roots.4 Israel. The purpose of this case report is to Reprint requests: Dr Joshua Moshonov, Department of describe an endodontic treatment that was Endodontics, Hebrew University, Hadassah School of Dental Medicine, POB 12272, Ein-Kerem, Jerusalem 91120, Israel. Fax: complicated by iatrogenic displacement of 972-2-6446956. E-mail: [email protected] amalgam into the root canal.

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Fig 1 Preoperative radiograph during apexification. Note the extensive occlusal amalgam restoration. A mesiodens is located between the central incisors. Fig 2 Diagnostic radiograph of the amalgam mass obliterating the root canal. Fig 3 Bypassing the amalgam mass with a K-file.

CASE REPORT in normal limits. The radiograph showed radiopacity of the root canal space with a A 9.5-year-old girl was referred to the denser radiopacity apical to the middle of the Department of Endodontics at the Hebrew canal, and a mesiodens between the two University Hadassah School of Dental central incisors (Fig 2). Medicine because of an amalgam mass After administration of local anesthesia lodged in the root canal of her maxillary right and isolation of the tooth with a rubber dam, central incisor. The child was healthy, and the amalgam mass was bypassed with a no. her medical history did not reveal any dis- 20 K-file (Fig 3). Enhanced vision, using a ease or allergies. The dental history revealed loupe lens with 3.5 magnification and illu- that the patient had suffered a traumatic mination, was invaluable for the treatment. injury to her permanent maxillary central inci- Biomechanical preparation of the root canal sors 4 months previously, resulting in intru- was carried out by the no. 50 H-file, alter- sion and an uncomplicated fracture of the nately using copious amounts of 0.5% sodi- right central incisor, as well as lateral luxation um hypochlorite solution and RCPrep of the left central incisor. Orthodontic extru- (Premier Dental Products). A Master Apical sion was then initiated. File radiograph revealed that the amalgam One month later, a radiolucency was iden- mass had loosened and broken into two tified in the periapical area of the maxillary pieces (Fig 4). Three H-files were then insert- right central incisor, and the results of the ed into the canal and wrapped around the vitality test were negative. Since the tooth mass, and the amalgam was withdrawn from was immature, an apexification procedure the root canal. A calcium hydroxide dressing was initiated, using Calxyl (Caulk). The coro- was applied to the root canal. Two weeks nal access cavity was sealed with amalgam later, the tooth appeared asymptomatic, and (Fig 1). Three months later, in an attempt to the canal was obturated with gutta-percha remove the amalgam, it was accidentally dis- and AH-26 (Dentsply) (Fig 5). placed into the root canal. At that stage, the Several months after completion of treat- patient was referred to our clinic. ment, the mesiodens was surgically removed Clinical examination of the patient and the root canal of the maxillary left central revealed discoloration of the tooth, which incisor was obturated. At the 1-year follow- responded to percussion and palpation with- up, the tooth remained asymptomatic.

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Fig 4 The amalgam mass has broken into 2 pieces. Fig 5 Postoperative radiograph.The amalgam was removed entirely from the root canal.The root canal was obturated using lateral condensation. Fig 6 One-year follow-up radiograph. Note the condition of the periodontal ligament. The mesiodens was surgically removed.

Subsequent radiographs showed a continu- been attributed to the large crown fracture, ous periodontal ligament surrounding the appeared at the apex, and the performing cli- tooth (Fig 6). nician decided to start root canal treatment. Amalgam was used as the provisional restorative material, and calcium hydroxide was introduced into the canal space for apex- DISCUSSION ification. Although the application of calcium hydroxide paste as the intracanal medication Rapid and appropriate treatment of dental is advocated in cases of immature intruded trauma can lessen its impact. The Interna- teeth,12,13 the use of amalgam as the coronal tional Association of Dental Traumatology has seal is questionable. In spite of the fact that published guidelines for the treatment of den- provisional restorative materials like IRM tal injuries. The treatment modality suggested (Dentsply Caulk) may jeopardize the sealed for an immature intruded tooth is to slightly tooth owing to microleakage,14 Cavit (3M luxate the tooth with forceps. Spontaneous Espe) or TERM (Dentsply Maillefer) could reeruption is then expected for teeth with have provided a better seal15,16 without com- incomplete root formation. When root forma- plicating the endodontic treatment, as in our tion has been completed, orthodontic reposi- case. tioning or surgical repositioning is performed. The retrieval of an amalgam mass from In case of completed root formation, prophy- the canal space differs from the retrieval of lactic extirpation is necessary and should be other foreign objects because of the large carried out within 1 to 3 weeks of injury.10 The volume involved and the inability to grasp it uncomplicated crown fracture should be with the Masserann or the endo-extractor. treated with a temporary glass-ionomer Therefore, as Friedman suggested, the pri- cement or a permanent restoration, using a mary objective was to bypass this large bonding agent. If the injury is very close to the mass.3 pulp, a calcium hydroxide dressing should be A no. 20 K-file bent at the end served as considered.11 an explorer for the detection of a gap In this case, orthodontic treatment was ini- between the foreign object and the canal tiated without waiting for spontaneous walls. Once such a gap is found it can serve reeruption. A radiolucency, which may have as a pathway for guiding larger instruments

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into the apical portion of the canal and 5. Plack WF, Vire DE. Retrieval of endodontic silver beyond the obstructing object. At this stage, points. Gen Dent 1984;32:124–129. the use of loupes or an operating micro- 6. Nagai O, Tani N, Kabaya Y, Komada S, Osada T. Ultrasonic removal of broken instruments in root scope is strongly advised. After this initial canals. Int Endod J 1986;16:298–304. step in the present case, the amalgam broke 7. Suter B. A new method for retrieving silver points into two pieces, and ultrasonic devices were and separated instruments from root canals. J then used to dislodge and loosen the amal- Endod 1998;24:446–448. gam from the canal walls.6–9 Retrieval was 8. Hulsmann M. Methods for removing metal obstruc- achieved with the aid of three Hedstrom files, tions from the root canal. Endod Dent Traumtol which were inserted between the amalgam 1993;9:223–227. mass and the canal walls and twisted around 9. Hulsmann M. Removal of fractured instruments using a combined automated/ultrasonic technique. the object. It was then possible to pull out the J Endod 1994;20:144–147. amalgam in the same manner as described 10. Flores MT, Andreasen JO, Bakland LK, et al; for the retrieval of separated instruments or International Association of Dental Traumatology. silver cones from the canal.9 This enabled Guidelines for the evaluation and management of completion of the endodontic treatment, and traumatic dental injuries. Dent Traumatol 2001; after the canal had been dressed with calci- 17:145–148. um hydroxide for an additional 2 weeks, it 11. Flores MT, Andreasen JO, Bakland LK, et al. International Association of Dental Traumatology. was endodontically obturated. A year later, Guidelines for the evaluation and management of the follow-up examination revealed complete traumatic dental injuries. Dent Traumatol 2001;17: recovery of the periodontal ligament without 97–102. any clinical symptoms. 12. Jacobs SG. The treatment of traumatized perma- The method described in this article can nent anterior teeth: Case report and literature also be applied to remove other foreign review. Part I—Management of intruded incisors. Aust Orthod J 1995;13:213–218. objects obstructing the root canal. 13. Andreasen JO, Andreasen FM, Bakland LK, Flores MT. Endodontic implications of dental trauma. In: Traumatic Dental Injuries: A Manual. Blackwell, 2003:58–61.[Au: Please list the editor(s) of the book REFERENCES and the location of the publisher.] 14. Carman JE, Wallace JA. An in vitro comparison of 1. Friedman S, Stabholz A, Tamse A. Endodontic microleakage of restorative materials in the pulp retreatment—Case selection and technique. 3. chambers of human molar teeth. J Endod 1994;20: Retreatment techniques. J Endod 1990;16:543–549. 571–575. 2. Stewart GG. Chelation and flotation in endodontic 15. Lee YC, Yang SF, Hwang YF, Chueh LH, Chung KH. practice: An update. J Am Dent Assoc 1986;113: Microleakage of endodontic temporary restorative 618–622. materials. J Endod 1993;19:516–520. 3. Friedman S. Endodontic retreatment. Alpha 16. Deveaux E, Hildelbert P,Neut C, Boniface B, Romond Omegan 1990;83:32–37. C. Bacterial microleakage of Cavit, IRM, and TERM. 4. Stabholz A, Friedman S, Tamse A. Endodontic fail- Oral Surg Oral Med Oral Pathol 1992;74:634–643. ures and retreatment. In: Cohen S, Burns RC (eds). Pathways of the Pulp. St Louis: Mosby, 1994: 690–729.

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