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Retrieving broken endodontic instruments
Retrieving broken endodontic instruments
George Feldman, Charles Solomon, DDS Peter Notaro, DDS Eli Moskowitz, DDS, Brooklyn, NY
The use of trepan burs and fiber optics permits a practitioner to remove fragments of broken endo dontic instruments from any location in the root canal. After the canal has been enlarged, the trepan burs are used to free the tip of the instrument frag ment. Fiber optics illuminate the fragment in the canal while the burs are being used. The fragment is extracted with use of a hollow tube inserted over the free tip of the broken instrument.
The removal of a broken endodontic instrument from a root canal has been a serious problem of dentists for decades. Solvents and chelating agents can penetrate foot canals obstructed by old root canal fillings or calcifications. Even sil ver points can be easily removed with conven tional instruments. However, because of its hard steel composition, the broken portion of an endo dontic instrument cannot be removed easily with any of the usual techniques. In a recent article, Fox and co-workers1 re ported that root canals filled with files either accidentally or intentionally were no more in clined toward treatment failure than were canals filled with conventional filling materials. The filling of the canal is only one part of endodontic treatment. We are not as concerned with the fil ling technique used in the obturation of a root canal as with the cleansing of the canal. If an in strument breaks before completion of the bio mechanical preparation of the canal, the successfailure ratio for the treatment is adversely affect ed.2 Following are four procedures that can be used to retrieve pieces of broken instruments. In one method, the fragment is bypassed and the apex is reached with the use of a new fine file and then files of increasing sizes. In this manner ade quate biomechanical preparation and subsequent 588 ■ JADA, Vol. 88, March 1974
filling can be achieved. The broken portion of the instrument is sealed within the canal. This technique is best used in straight canals. In another method a broach wrapped in cotton is worked into the canal in the hope that the brok en piece will become enmeshed in the cotton. As the broach is withdrawn, the instrument frag ment may be pulled out with it. This technique is limited to situations in which the fragment is barbed and is not tightly wedged in the root canal. Splinter forceps are used in a third method. Small half-round burs in a slow-speed contraangle are used to form a groove around the piece of the broken instrument. With the use of splinter forceps, the piece is grasped and removed. This is the best procedure if the instrument is broken near the coronal portion of the canal and the co ronal portion is wide. New rasps with sharp cutting edges are worked alongside the broken instrument in the fourth method. The grooves of the fragment are en gaged and it is extracted as the rasp is withdrawn. The use of this technique is most successful for the retrieval of large fragments because the large sized rasps can be used. Recently, instruments making use of trepan burs have been developed by Masserann.3 In almost every situation, pieces of broken instru ments can be removed with the use of trepan burs and a modification of his technique. We found that fiber optics are invaluable in the proper use of the burs. The thin cylindrical fibers of glass channel light that can be intense, yet cool, at the terminals. A standard-sized tip is no larger than 2 mm in diameter (Viconex*). Because of its small size and the coolness of the light, the fiber optic can contact tissues of the oral cavity without causing damage.
Objectives
The canal coronal to the instrument fragment is prepared so that a metal tube (an Extractor!)
Fig 1 ■ Peeso engine reamer reaches broken instrument.
Fig 2 ■ Trepan bur cuts tooth structure around fragm ent. Fiber o p tic probe in position.
can be inserted and made to grasp the fragment. The canal must be straight and wide enough to accommodate the rigid Extractor. A small por tion of the instrument fragment at the base of the preparation must be freed so that the Extractor can slip over it.
Technique
A no. 3 Peesot bur is used to prepare the canal until contact with the fragment is made (Fig 1). This fluted twist bur guides itself without per forating the walls of the canal. The bur also re moves any undercuts in the canal, and widens the canal enough to accommodate the Extractor. If the canal is narrow, it must be enlarged first with hand files and Peeso burs of smaller sizes before the no. 3 bur is used. Next, a few millimeters of the piece of the bro ken instrument must be freed. This is done with a trepan bur. The trepan bur is a hollow tube with peripheral edges made to cut tooth structure.
The bur is rotated counterclockwise with a reducing-speed contra-angle instrument. Enough tooth structure must be removed so that at least 2 mm of the instrument fragment is free. The size of the bur originally used varies according to the diameter of the fragment; the sizes of the burs are increased until at least a no. 13 trepan bur is used so that the channel is large enough to accommodate the Extractor. A fiber optic is used to illuminate the fragment in the root canal. The fiber optic probe can be placed perpendicular to the root on the gingiva several millimeters below the cervical area, or directly on the tooth structure at the cervical area (the probe is directed into the root and in clined toward the apex). The exact placement of the probe for maximum illumination is found by trial and error, but this takes only a few seconds. The transilluminating light enables the practi tioner to see directly into the root canal and to position the rotating trepan bur over the frag ment (Fig 2). The light makes accidental perfo ration improbable and permits the practitioner to see how much of the fragment is free in the canal. Feldman— others: RETRIEVING ENDODONTIC INSTRUMENTS ■ 589
Fig 3 ■ E ndo don tic explorer can be used to position fragm ent in curved canal.
T he freed portion of the instrum ent at the base of a curved canal may press against one wall of the preparation because of the spring of the m et al. Transillum ination with a fiber optic will help the practitioner to see this. T he fragm ent can be repositioned m ore favorably with an endodontic explorer (Fig 3). T he E xtractor is now inserted into the canal; its open end slides over the free part of the fragment. T he fragm ent is locked into the E xtractor by tightening of the screw plunger (Fig 4). We use two heavy-beaked pliers to lock th e plunger securely. W ith a counterclockw ise m ovem ent of the handle o f the E xtractor, the fragm ent is eased out of the canal.
Fig 4 ■ Fragm ent is grasped w ith Extractor.
Fig 5 ■ Left, radiograph shows instrum ent fragm ent in canal of m axillary canine. Center, radiograph taken im m ediately after fragm ent was removed. Right, ro ot canal is filled and canal prepared fo r post.
Fig 6 ■ Left, instrum ent fragm ent is seen in lingual root of m axillary first premolar. Right, after instrum ent was removed, both canals were filled w ith gutta-percha.
590 ■ JADA, Vol. 88, March 1974
Fig 7 ■ Left, instrum ent fragm ent is located in one distal canal of m andibular first molar. Center, radiograph taken im m ediately after removal of fragm ent. Right, both distal canals filled w ith gutta-percha.
Fig 8 ■ Left,
radiograph show s
piece
of
broken instrum ent in distobuccal canal of m axillary molar. Right, instrum ent removed and canal filled w ith silver points.
We found th at this technique is the m ost con sistently effective way of removing pieces of bro ken endodontic instrum ents from root canals. Radiographs (Fig 5-8) show the removal of in strum ent fragm ents from single- and multi-rooted maxillary and m andibular teeth. T he canals were later filled with gutta-percha or silver points. The cases show the extent to which the teeth can be treated. T he type o f root canal filling and the type of final restoration used after com pletion of endodontic treatm ent are not restricted.
Dr. Feldman is chief of endodontics at the K ingsbrook Jewish Medical Center, the Jewish Hospital of Brooklyn, and the Brookdale Medical Center. His address is 1 Hanson Place, Brooklyn, NY 11217. Dr. S olom on is adjunct assistant professor of dentist
ry, C olum bia University dental school, and serves in the endo d o n tic departm ent of the Jewish Hospital o f B rooklyn. Dr. Notaro is clinical chief of endodontics, K ingsbrook Jewish Medical C en ter, and is w ith the e n dodontic departm ent of the B rookdale Med ical Center. Dr. Moskowitz is w ith the en dodo ntic departm ents of the Brookdale Medical Center and the Jewish Hospital of B rooklyn, and is endodontic consultant at G reenpoint Hospital o f Brooklyn.
*Vicon P roducts Corp., Mamaroneck, NY 10543. tM edidenta, W oodside, NY 11377. ¿Union Broach Co., Inc., Long Island City, NY 11101.
1. Fox, J., and others. Filing ro ot canals w ith files: radiograph ic evaluation o f 304 cases. NY State Dent J 38:154 March 1972. 2. Stewart, G, Im portance of chem om echanical preparation of the root canal. Oral Surg 8:993 Sept 1955. 3. Masserann, J. Entfernen M etallischer Fragm ente aus W ur zelkanalen, translation. J Br Endodont Soc 5:55 Autum n 1971.
Feldman— others: RETRIEVING ENDODONTIC INSTRUMENTS ■ 591
George Feldman, Charles Solomon, DDS Peter Notaro, DDS Eli Moskowitz, DDS, Brooklyn, NY
The use of trepan burs and fiber optics permits a practitioner to remove fragments of broken endo dontic instruments from any location in the root canal. After the canal has been enlarged, the trepan burs are used to free the tip of the instrument frag ment. Fiber optics illuminate the fragment in the canal while the burs are being used. The fragment is extracted with use of a hollow tube inserted over the free tip of the broken instrument.
The removal of a broken endodontic instrument from a root canal has been a serious problem of dentists for decades. Solvents and chelating agents can penetrate foot canals obstructed by old root canal fillings or calcifications. Even sil ver points can be easily removed with conven tional instruments. However, because of its hard steel composition, the broken portion of an endo dontic instrument cannot be removed easily with any of the usual techniques. In a recent article, Fox and co-workers1 re ported that root canals filled with files either accidentally or intentionally were no more in clined toward treatment failure than were canals filled with conventional filling materials. The filling of the canal is only one part of endodontic treatment. We are not as concerned with the fil ling technique used in the obturation of a root canal as with the cleansing of the canal. If an in strument breaks before completion of the bio mechanical preparation of the canal, the successfailure ratio for the treatment is adversely affect ed.2 Following are four procedures that can be used to retrieve pieces of broken instruments. In one method, the fragment is bypassed and the apex is reached with the use of a new fine file and then files of increasing sizes. In this manner ade quate biomechanical preparation and subsequent 588 ■ JADA, Vol. 88, March 1974
filling can be achieved. The broken portion of the instrument is sealed within the canal. This technique is best used in straight canals. In another method a broach wrapped in cotton is worked into the canal in the hope that the brok en piece will become enmeshed in the cotton. As the broach is withdrawn, the instrument frag ment may be pulled out with it. This technique is limited to situations in which the fragment is barbed and is not tightly wedged in the root canal. Splinter forceps are used in a third method. Small half-round burs in a slow-speed contraangle are used to form a groove around the piece of the broken instrument. With the use of splinter forceps, the piece is grasped and removed. This is the best procedure if the instrument is broken near the coronal portion of the canal and the co ronal portion is wide. New rasps with sharp cutting edges are worked alongside the broken instrument in the fourth method. The grooves of the fragment are en gaged and it is extracted as the rasp is withdrawn. The use of this technique is most successful for the retrieval of large fragments because the large sized rasps can be used. Recently, instruments making use of trepan burs have been developed by Masserann.3 In almost every situation, pieces of broken instru ments can be removed with the use of trepan burs and a modification of his technique. We found that fiber optics are invaluable in the proper use of the burs. The thin cylindrical fibers of glass channel light that can be intense, yet cool, at the terminals. A standard-sized tip is no larger than 2 mm in diameter (Viconex*). Because of its small size and the coolness of the light, the fiber optic can contact tissues of the oral cavity without causing damage.
Objectives
The canal coronal to the instrument fragment is prepared so that a metal tube (an Extractor!)
Fig 1 ■ Peeso engine reamer reaches broken instrument.
Fig 2 ■ Trepan bur cuts tooth structure around fragm ent. Fiber o p tic probe in position.
can be inserted and made to grasp the fragment. The canal must be straight and wide enough to accommodate the rigid Extractor. A small por tion of the instrument fragment at the base of the preparation must be freed so that the Extractor can slip over it.
Technique
A no. 3 Peesot bur is used to prepare the canal until contact with the fragment is made (Fig 1). This fluted twist bur guides itself without per forating the walls of the canal. The bur also re moves any undercuts in the canal, and widens the canal enough to accommodate the Extractor. If the canal is narrow, it must be enlarged first with hand files and Peeso burs of smaller sizes before the no. 3 bur is used. Next, a few millimeters of the piece of the bro ken instrument must be freed. This is done with a trepan bur. The trepan bur is a hollow tube with peripheral edges made to cut tooth structure.
The bur is rotated counterclockwise with a reducing-speed contra-angle instrument. Enough tooth structure must be removed so that at least 2 mm of the instrument fragment is free. The size of the bur originally used varies according to the diameter of the fragment; the sizes of the burs are increased until at least a no. 13 trepan bur is used so that the channel is large enough to accommodate the Extractor. A fiber optic is used to illuminate the fragment in the root canal. The fiber optic probe can be placed perpendicular to the root on the gingiva several millimeters below the cervical area, or directly on the tooth structure at the cervical area (the probe is directed into the root and in clined toward the apex). The exact placement of the probe for maximum illumination is found by trial and error, but this takes only a few seconds. The transilluminating light enables the practi tioner to see directly into the root canal and to position the rotating trepan bur over the frag ment (Fig 2). The light makes accidental perfo ration improbable and permits the practitioner to see how much of the fragment is free in the canal. Feldman— others: RETRIEVING ENDODONTIC INSTRUMENTS ■ 589
Fig 3 ■ E ndo don tic explorer can be used to position fragm ent in curved canal.
T he freed portion of the instrum ent at the base of a curved canal may press against one wall of the preparation because of the spring of the m et al. Transillum ination with a fiber optic will help the practitioner to see this. T he fragm ent can be repositioned m ore favorably with an endodontic explorer (Fig 3). T he E xtractor is now inserted into the canal; its open end slides over the free part of the fragment. T he fragm ent is locked into the E xtractor by tightening of the screw plunger (Fig 4). We use two heavy-beaked pliers to lock th e plunger securely. W ith a counterclockw ise m ovem ent of the handle o f the E xtractor, the fragm ent is eased out of the canal.
Fig 4 ■ Fragm ent is grasped w ith Extractor.
Fig 5 ■ Left, radiograph shows instrum ent fragm ent in canal of m axillary canine. Center, radiograph taken im m ediately after fragm ent was removed. Right, ro ot canal is filled and canal prepared fo r post.
Fig 6 ■ Left, instrum ent fragm ent is seen in lingual root of m axillary first premolar. Right, after instrum ent was removed, both canals were filled w ith gutta-percha.
590 ■ JADA, Vol. 88, March 1974
Fig 7 ■ Left, instrum ent fragm ent is located in one distal canal of m andibular first molar. Center, radiograph taken im m ediately after removal of fragm ent. Right, both distal canals filled w ith gutta-percha.
Fig 8 ■ Left,
radiograph show s
piece
of
broken instrum ent in distobuccal canal of m axillary molar. Right, instrum ent removed and canal filled w ith silver points.
We found th at this technique is the m ost con sistently effective way of removing pieces of bro ken endodontic instrum ents from root canals. Radiographs (Fig 5-8) show the removal of in strum ent fragm ents from single- and multi-rooted maxillary and m andibular teeth. T he canals were later filled with gutta-percha or silver points. The cases show the extent to which the teeth can be treated. T he type o f root canal filling and the type of final restoration used after com pletion of endodontic treatm ent are not restricted.
Dr. Feldman is chief of endodontics at the K ingsbrook Jewish Medical Center, the Jewish Hospital of Brooklyn, and the Brookdale Medical Center. His address is 1 Hanson Place, Brooklyn, NY 11217. Dr. S olom on is adjunct assistant professor of dentist
ry, C olum bia University dental school, and serves in the endo d o n tic departm ent of the Jewish Hospital o f B rooklyn. Dr. Notaro is clinical chief of endodontics, K ingsbrook Jewish Medical C en ter, and is w ith the e n dodontic departm ent of the B rookdale Med ical Center. Dr. Moskowitz is w ith the en dodo ntic departm ents of the Brookdale Medical Center and the Jewish Hospital of B rooklyn, and is endodontic consultant at G reenpoint Hospital o f Brooklyn.
*Vicon P roducts Corp., Mamaroneck, NY 10543. tM edidenta, W oodside, NY 11377. ¿Union Broach Co., Inc., Long Island City, NY 11101.
1. Fox, J., and others. Filing ro ot canals w ith files: radiograph ic evaluation o f 304 cases. NY State Dent J 38:154 March 1972. 2. Stewart, G, Im portance of chem om echanical preparation of the root canal. Oral Surg 8:993 Sept 1955. 3. Masserann, J. Entfernen M etallischer Fragm ente aus W ur zelkanalen, translation. J Br Endodont Soc 5:55 Autum n 1971.
Feldman— others: RETRIEVING ENDODONTIC INSTRUMENTS ■ 591