ENDODONTOLOGY Volume: 25 Issue 2 December 2013 Case Report Retrieval of a separated instrument from the root canal followed by non-surgical healing of a large periapical lesion in maxillary incisors - A case report Raju Chauhan # * Anil Chandra # ** Shweta Singh ## * ABSTRACT One of the most common mishaps that occur during routine endodontic treatment is the fracture of instrument inside the root canal. The separated instrument, particularly a broken file leads to metallic obstruction in the root canal and prevents thorough cleaning and shaping procedures. Continuous pain or discomfort occurs in the involved tooth if the broken instrument is not removed or bypassed. There are several methods and techniques available to retrieve the separated instruments from the root canal. This article describes the successful removal of a broken instrument from the root canal of a maxillary central incisor using Instrument Removal System (irs) followed by healing of a large radiolucency applying non surgical approach in relation to maxillary central and lateral incisors. Key words: Instrument Removal System, root canal treatment, separated instrument, non-surgical root canal treatment Introduction In routine endodontics a clinician may encounter with many procedural errors and obstacles which may alter the course of treatment at any stage (1). One of these procedural errors is the fracture of instrument inside the root canals. Many clinicians associate broken instruments with separated files, but the term could also apply to a sectioned silver point, a segment of a lentulo, a gates glidden drill, lateral or finger spreaders, and paste fillers and they can be made from nickel-titanium (NiTi), stainless steel or carbon steel (2). During root canal preparation procedures, the potential for instrument breakage is always present. There are three possible outcomes that may be encountered when treating these cases: (i) Retrieval, (ii) Bypass and sealing the fragment within the root canal space, (iii) True blockage. With the advent of rotary NiTi files, there has been an unfortunate increase in the occurrence of broken instrument (3). Today, separated instruments can usually be removed due to technological advancements, ultrasonic instrumentation, and microtube delivery methods (4-5). Specifically, the dental operating microscope allows clinicians to visualize most broken instruments (6). The ability to non-surgically access and remove a broken instrument will be influenced by the diameter, length and position of the obstruction within a canal and the type of the metallic object (2, 7). Instruments located in the straight portion of the canal can usually be removed (8). When a fractured instrument lies partially around the canal curvature, but the coronal aspect can still be visualized and accessed, then removal may or may not be possible. If the entire segment of the broken instrument is apical to the curvature and safe access with visualization is not possible, then nonsurgical removal usually cannot be # Dept. of Conservative Dentistry and Endodontics, ## Dept. of Oral and Maxillofacial Pathology, * Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh, ** King George Medical University, Lucknow, Uttar Pradesh 68
RETRIEVAL OF A SEPARATED INSTRUMENT FROM THE ROOT CANAL FOLLOWED BY NON-SURGICAL HEALING OF A LARGE PERIAPICAL LESION IN MAXILLARY INCISORS : A CASE REPORT accomplished (8). Traditionally, retrieving broken instruments posed formidable challenges. Over time, retrieval techniques evolved but were oftentimes ineffective because of limited vision and/ or restricted space. Leaving a fractured instrument inside the root canal coupled with incomplete obturation or ineffective coronal seal may lead micro-organisms to penetrate inside the canal and develops periapical lesion. Oztan and Soares et al. have confirmed that large periapical lesions can respond favorably to nonsurgical treatment using calcium hydroxide paste (9, 10). performed on tooth #7 and 8 revealed the nonvitality of both teeth. Periapical radiograph was taken in relation to tooth #7 and 8, which showed a broken instrument inside the root canal of tooth No. 8 and poorly obturated tooth #7. A large periapical lesion was seen in relation to both maxillary right central and lateral incisors (Fig.a) This paper describes a case report in which a separated file has been removed from the root canal of a maxillary central incisor using microtube system, Instrument Removal System (irs) followed by healing of a large periapical lesion using non surgical approach. Case Report A 25 year old female patient reported in the post graduate clinic of Department of Conservative Dentistry and Endodontics of our institute with chief complaint of pain in relation to upper front teeth. Patient gave history of root canal treatment in upper front teeth at a private clinic, 3 years back. Patient was experiencing pain in the same teeth since 3-4 months. Clinical examination revealed the presence of glass-ionomer restorations in tooth # 7 and 8. There was no associated swelling in relation to the involved teeth. Both teeth were tender on percussion. Surrounding gingival tissue appeared inflamed but the pocked depths were within the normal limits. Sensibility tests (EPT and cold test) Figure (a) A preoperative periapical radiograph showing a separated instrument in maxillary right central incisor, poorly obturated maxillary right lateral incisor and a large periapical lesion in relation to both teeth. Non-surgical root canal retreatment was planned and the patient was informed about the treatment plan. Root canal retreatment was initiated in tooth #7 under the rubber-dam isolation. The previous restoration was removed and the access opening was enlarged. Gutta-percha and the sealer were removed from tooth #7 using Hedstroem files (Dentsply International) and Gates-Glidden drills (Dentsply International) frequently irrigating with 2% sodium hypoclorite. The central incisor was then isolated with rubber-dam and the older restoration was removed to gain access to the pulp chamber. Modified Gates-Glidden drills (Dentsply International) were used to create circumferential 69
RAJU CHAUHAN, ANIL CHANDRA, SHWETA SINGH staging platform to expose 2-3 mm of the coronal most part of the broken instrument (Fig. b). was unwound and removed by rotating the microtube and screw wedge assembly counter clockwise. A piece of broken H-file was attached to the Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma) when it was removed from the root canal (Fig. d). A radiograph was then taken to confirm the retrieval of obturation material and the separated instrument from tooth #7 and 8 respectively (Fig. e). (b) The coronal most part of the obstruction was exposed by removing the surrounding dentin (arrow). (d) The separated instrument successfully retrieved from the root canal. (c) The instrument was wedged inside the Instrument Removal System (arrow). The Instrument Removal System (irs) microtube (Dentsply, Tulsa Dental, Tulsa, Oklahoma) was then selected and inserted inside the canal of tooth No. 8 to engage the coronal-most part of the broken instrument (Fig. c). After positioning the microtube, the same color coded screw wedge was inserted and slid internally through the microtube s length until it contacts the obstruction. The instrument was engaged by gently turning the screw wedge handle counter clockwise by a few degrees. When engaged, the obstruction (e) radiograph showing the teeth after retrieval of instrument and the previous obturation material. 70
RETRIEVAL OF A SEPARATED INSTRUMENT FROM THE ROOT CANAL FOLLOWED BY NON-SURGICAL HEALING OF A LARGE PERIAPICAL LESION IN MAXILLARY INCISORS : A CASE REPORT iodoform (Metapex, Meta Biomed, Korea) were given in both teeth three-four times over a period of 2-3 months. Obturation was done with cold lateral condensation using AH Plus sealer (Dentsply Caulk) and gutta-percha when the patient became asymptomatic (Fig. g). Access openings were sealed with restorative resin. Patient was then recalled after six months to evaluate the periapical healing. Radiograph taken at six months recall revealed the dramatic reduction in periapical radiolucency and the formation of trabecular pattern of bone at the apex of involved teeth (Fig. h). (f) Radiographic confirmation of working lengths. (g) Radiograph showing obturation of both teeth. Working lengths were estimated in tooth #7 and 8 using apex locator (Root ZX, J. Morita USA, Inc.) and confirmed with periapical radiograph (Fig. f). Biomechanical preparation was completed by step-back technique using 2% sodium hypoclorite and 17% ethylenediamenetetraacetic acid (EDTA) (Glyde, Dentsply International). Interappointment dressings of calcium hydroxide and (h) Six months post operative radiograph showing dramatic reduction of periapical lesion and formation of trabecular pattern of bone at the apex of affected teeth (arrows). Discussion One of the most troublesome incidents is the fracture of endodontic instruments within root canal. Many objects have been reported to break and subsequently become lodged in root canals. Nails, pencil leads, toothpicks, tomato seeds, hat pins, needles, pins and other metallic objects, were listed in 1987 by Chenail and Teplitsky (11). 71
RAJU CHAUHAN, ANIL CHANDRA, SHWETA SINGH The removal of foreign objects sometimes is difficult and the success rate has been reported as 55% to 79% (12). Several methods are described to remove broken instruments or objects within root canals. The evaluation of fractured instrument removal systems and techniques such as the Masserann Kit, (13) Endo Extractor (Brasseler USA Inc., Savannah, GA), (14) wire loop technique, (15) the Canal Finder System (16) (Fa.Societé Endo Technique, Marseille, France), and ultrasonic devices (17) have all shown limitations. The limitations of these devices include excessive removal of root canal dentin, ledging, perforation, limited application in narrow and curved roots, and extrusion of the fractured portion through the apex (12, 17). The operative microscope and Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma) have successfully overcome the drawbacks of earlier techniques to some extent (5). The use of Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma) considerably causes less damage to radicular dentin and it is comfortable for the operator (6). Nevertheless, successful removal of such obstructions relies on factors such as the position of the instrument in relation to the canal curvature, depth within the canal, and the type of fractured instrument (18). The more apical the location of the fractured instrument the greater the potential for root perforation and the lower the fracture resistance of the root after removal of the instrument. Straightline access is mandatory for successful removal of instruments, but conservation of tooth structure is paramount to the tooth s resistance to fracture The Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma) is indicated when ultrasonic efforts prove to be unsuccessful and may be used to remove broken instruments that are lodged in the straightaway portions of the root or partially around the canal curvature (5, 8). The black instrument has an outside diameter of 1.00 mm and is designed to work in the coronal one third of larger canals, whereas the red and yellow instruments have outside diameters of 0.80 and 0.60 mm, respectively, and can be placed deeper into more narrow canals. Each complete instrument is comprised of a color coordinated microtube and screw wedge. The separated instrument was recovered conveniently using the black instrument of Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma). In the present case report healing of a large periapical lesion was achieved non-surgically by placing calcium hydroxide and iodoform paste inside the root canal. Healing of a large periapical lesions have been successfully carried out by packing calcium hydroxide inside the root canal (9,10,19). The exact mechanism of action of calcium hydroxide is still speculative. Ghose et al. has advocated that direct contact between the calcium hydroxide and the periapical tissue was necessarily beneficial for osseoinductive reasons (20). The success of the conservative treatment of periapical lesions could be explained by following aspects: a) the effect of biomechanical preparation on intracanal microbiota; b) complementary antiseptic action of calcium hydroxide due to alkanility; and c) effect of calcium hydroxide on bony repair (10). The benefits of calcium hydroxide include antiinflammatory action through its hygroscopic properties, such as forming calcium-proteinate 72
RETRIEVAL OF A SEPARATED INSTRUMENT FROM THE ROOT CANAL FOLLOWED BY NON-SURGICAL HEALING OF A LARGE PERIAPICAL LESION IN MAXILLARY INCISORS : A CASE REPORT bridges and inhibiting the phospholipase; the neutralization of acidic products; activation of alkaline phosphatase; and antibacterial action (21). We are able to remove the separated instrument from the root canal using Instrument Removal System (irs) (Dentsply, Tulsa Dental, Tulsa, Oklahoma) along with non-surgical healing of a large periapical lesion associated with the involved teeth. Conclusion The Instrument Removal System (irs) in combination with Gates-Glidden drills is an effective method to remove separated instrument from the root canal if it lies in the straighter portion of the canal or when a straight line access can be obtained to locate the coronal-most end of the instrument. Large periapical lesions can be treated non-surgically by placing calcium hydroxide and iodoform paste inside the canal over a period of time. References : 1. Torabinejad M, Lemon RR. Procedural accidents. In: Walton R, Torabinejad M, eds. Principles and practice of endodontics. Philadelphia: W.B. Saunders Company, 2002:310-330. 2. Parashos P, Messer HH. Rotary NiTi instrument fracture and its consequences. J Endod 2006;32:1031 1043. 3. Ankrum MT, Hartwell GR, Truitt JE. K3 Endo, ProTaper, and ProFile systems: breakage and distortion in severely curved roots of molars. J Endod 2004;30:234 7. 4. Plotino G, Pameijer CH, Grande NM, Somma F. Ultrasonics in endodontics: A review of the literature. J Endod 2007;33:81-95. 5. Ruddle CJ. Broken instrument removal. The endodontic challenge. Dent Today 2002;21:70 72, 74, 76 passim. 6. Suter B, Lussi A, Sequeira P. Probability of removing fractured instruments from root canals. J Endod 2005;38:112 123. 7. Terauchi Y et al. Evaluation of the efficiency of a new fileremoval system in comparison with two conventional systems. J Endod 2007;33:585 588. 8. Roda RS, Gettleman BH. Non surgical retreatment. In: Hargreaves KM, Cohen S, eds. Pathways of the pulp, ed. 10 St. Louis: Mosby; 2011:890-952. 9. Öztan MD. Endodontic treatment of teeth associated with a large periapical lesion. Int Endod J 2002;35:73-78. 10. Soares JA, Brito-Junior M, Silveira FF, Nunes E, Santos SM. Favourable response of an extensive periapical lesion to root canal treatment. J Oral Sci 2008;50:107-111. 11. Chenail BL, Teplitsky PE. Orthograde ultrasonic retrieval of root canal obstructions, J Endod 1987;13:186-190. 12. Hülsmann M. Methods for removing metal obstructions from the root canal. Endod Dent Traumatol 1993;9:223-237. 13. Masserann J. New method for extracting metallic fragments from canals. Inf Dent 1972;54:3987 4005. 14. Gettleman BH, Spriggs KA, ElDeeb ME, Messer HH. Removal of canal obstructions with the Endo Extractor. J Endod 1991;17:608 611. 15. Roig-Greene JL. The retrieval of foreign objects from root canals: a simple aid. J Endod 1983;9:394-397. 16. Hülsmann M. The removal of silver cones and fractured instruments using the canal finder system. J Endod. 1990;16:596-600. 17. Gaffney JL, Lehman JW, Miles MJ. Expanded use of the ultrasonic scaler. J Endod 1981;7:228 229. 18. Gencoglu N, Helvacioglu D. Comparison of the different techniques to remove fractured endodontic instruments from root canal systems. Eur J Dent 2009;3:90-95. 19. Caliskan MK. Prognosis of large cyst-like periapical lesions following non-surgical root canal treatment: a clinical review. Int Endod J 2004;37:408-416. 20. Ghose LJ, Baghdady VS, Hikmat YM. Apexification of immature apices of pulpless permanent anterior teeth with calcium hydroxide. J Endod 1987;13:285 290. 21. Siqueira JF Jr, Lopes HP. Mechanisms of antimicrobial activity of calcium hydroxide: a critical review. Int Endod J 1999;32:361-369. 73