Braz Dent J (1998) 9(1): 57-60 ISSN 0103-6440
| Introduction | Case Report | Results | Discussion | Conclusion | References |
The purpose of this work is to report a clinical case of removal of
a fractured endodontic instrument in the root canal of a maxillary molar,
when part of this fragment extended through the apical foramen. In the
present case, many methods were tried without satisfactory results. Therefore,
an alternative device utilizing cyanoacrylate adhesive was tested with
sucess. This method proved to be practical, and the advantages it offers
should make it a useful device in the dentist’s office.
Key Words: retrieval, broken endodontic instrument, cyanoacrylate adhesive.
An instrument fractured in the root canal occurs frequently during endodontic
therapy. In most cases, it causes anxiety and frustration for experienced
endodontists when trying to remove this fragment.
De Deus (1992) reported that endodontic instruments must be carefully used and instruments that show even slight deformities should be discarded. Sotokawa (1988) also reported that metal fatigue was found to be implicated in breakage. Ingle and Beveridge (1979) reported that surgery should be performed only when clinical devices have been tried without success.
Many techniques, methods and instruments have been proposed for the removal of foreign bodies, broken instruments, silver cones and cemented posts in root canals, i.e., Canal Finder system, Masseran Kit, Endo Extractor System, Ultrasonics, and several kinds of pliers.
Feldman et al. (1974) reported the removal of broken instruments from single root and multiple roots with the Endo Extractor System. Sieraski and Zillich (1993) used the ultrasonic scaler that produces less dentin wear as already reported by Souyave et al. (1985) and Meidinger and Kabes (1985). The Canal Finder System can also be used successfully according to Hüllsman (1990) in an experimental and clinical study.
Fors and Berg (1993) reported a clinical case of removal of a broken file in the mesio-buccal canal of a mandibular third molar using a micro-surgical Castroviejos needle holder for ophthalmology. Weissman (1993) also reported the use of a perry pliers for removal of a silver cone.
A 20-year-old white female was referred to the Post Graduate Endodontic
Department, University of Rio de Janeiro (UERJ), Brazil, requiring endodontic
re-treatment and removal of a Macspadden compactor broken in the palatine
root canal of the first maxillary molar. The instrument extruded the foramen
about 4 mm as shown in Figure 1.
First visit: After tooth isolation and removal of the gutta-percha from the palatine canal, the compactor was exposed and attempts to loosen it with Hedströen and Kerr files proved to be impossible. Thus, the tooth was then sealed temporarily.
Second visit: After sealer removal, the tooth was isolated with a rubber dam and the canal was widely enlarged with Gates-Glidden drills and diamond burs. The pulp chamber and the root canal were illuminated using fiber optics to make access to the instrument easier. The coronal tip of the instrument was then exposed and positioned in the center of the canal. A variety of forceps and pliers such as Stieglits and modified hemostatic pliers were utilized. However the compactor was not loosened. The compactor could not be removed because it was “screwed” at the foramen by the spirals. Moreover, these pliers were not rigid enough to permit a strong grip for the removal of the broken object. Other methods including Ultrasonic scaler and canal Finder System were also not successful.
Third visit: The Extractor System Kit was used, with its trepan bur cutting the peripheral dentin to the compactor and the tip was still free in the canal. The “claws” of the extractor broke although the tube fit the compactor tip exactly. The trepan bur was slightly mashed for better adjustment and some cyanoacrylate adhesive was dropped inward. The outside of the tube was isolated with glycerol. An attempt to remove the instrument bonded to the tube as a single unit was then made. This complex was conducted to the compactor and waited for about three minutes for total adhesion.
A hemostatic pliers was then used to support the complex rotation. Processing a few minutes with slight and delicate clockwise movement (rotation) the compactor was totally removed from the root canal (Figures 2 and 3).
Fourth visit: Conservative re-treatment, biomechanical preparation and obturation with rolled gutta-percha associated with slightly lateral condensation technique was carried out. The patient returned to the referring dentist for restoration of the tooth.
Recall: Nine months later the patient was asymptomatic with no periapical lesion (Figure 4).
Many methods and instruments have been proposed to remove broken instruments
from root canals. Nevertheless, removal depends on the depth, width, canal
curvatures and access to the foreign body (Fors and Berg, 1983; Johnson
and Beatty, 1988). When the fragment is in the cervical area it can be
removed by pliers or Stieglitz forceps. Solvents and chelating agents have
also been reported to be useful (Feldman et al., 1974; Sieraski and Zillich,
1983). In the present case pliers were modified without successful results
(Fors and Berg, 1983; Vera-Moncayo et al., 1989), because there was not
enough pressure to keep the pliers from slipping off.
Ultrasonic scalers are very useful for the removal broken instruments, silver cones and posts. Some authors (Sieraski and Zillich, 1983; Krell et al., 1984; Souyave et al., 1985; Meidinger and Kabes, 1985) report the following advantages: practicality, effectiveness, minimal dentin loss. Souyave et al.(1985) reported that the Masseran Kit and Extractor System can cause fractures and perforation in some cases.
Despite all that has been reported, the previous enlargement of the dentin walls is essential for the capture of the instrument (Feldman et al., 1974; Fors and Berg, 1983; Weissman, 1983; Roig-Greene, 1983; Johnson and Beatty, 1988; Vera-Moncayo et al., 1989; Spriggs et al., 1990). Roig-Greene (1983) also reported that the tip of the object must be free in the center of the canal, far away from the canal dentin walls.
Conventional techniques must be tried but if they prove to be unsuccessful,
alternative devices should be used for the removal of broken endodontic
instruments. The following procedures were necessary for successful results:
a) Previous enlargement of the canal, promoting direct access to the instrument.
b) Fiber optic or surgical microscope must be used in all circumstances for full visual control.
c) If the instrument tip is resting against a dentin wall, it should be displaced and positioned toward the center of the root canal.
d) The tube with the adhesive must fit the external diameter of the instrument end tip exactly.
e) The cyanoacrylate adhesive proved to be safe and effective for clinical use.
De Deus QD: Endodontia 5th ed. Medsi, Rio de Janeiro, 1992
Feldman G, Solomon, C, Notaro P, Moscowitz E: Retrieving broken instruments. J Am Dent Assoc, 88: 588-591, 1974
Fors UGH, Berg JO: A method for the removal of broken endodontic instruments from root canals. J Endod 9: 156-159, 1983
Hülsmann M: The removal of silver cones and fractured instruments using the Canal Finder system. J Endod 16: 596-600, 1990
Ingle JI, Beveridge EE: Endodontia, translation Antonio Rothier, 2nd ed. Interamericana, Rio de Janeiro, 1979
Johnson WB, Beatty RG: Clinical technique for removal of root canal obstructions. J Am Dent Assoc 117: 473-476, 1988
Krell KV, Fuller MW, Scott GL: The conservative retrieval of silver cones in difficult cases. J Endod 10: 269-273, 1984
Meidinger DL, Kabes BJ: Foreign object removal from root canal utilizing the Cavi-Endo ultrasonic instrument. J Endod 11: 301-304, 1985
Roig-Greene JL: The retrieval of foreign objects from root canals: a simple aid. J Endod 9: 394-397, 1983
Sieraski SM, Zillich RM: Silver point retreatment: review and case report. J Endod 9: 35-39, 1983
Sotokawa T: Analysis of clinical breakage of root canal instruments. J Endod 14: 75-82, 1988
Souyave LCJ, Inglis AT, Alcalay M: Removal of fractured endodontic instruments using ultrasonics. Br Dent J 159: 251-253, 1985
Spriggs K, Gentleman B, Messer HH: Evaluation of a new method for silver points removal. J Endod 16: 335-338, 1990
Vera-Moncayo H, Garcia-Gutierrez AR, Navarrete-Cervantes JM, Delgadillo-Raygosa MM, Lopes-Lio MB: Technic for recovery of instruments fractured in the root canal using cyanoacrylate cement (in vitro). Pract Odont 10: 27-31, 1989
Weissman MI: The removal of difficult silver cones. J Endod 9: 210-211, 1983
Correspondence: Prof. Tauby Coutinho Filho, Faculdade de Odontologia, Universidade do Estado do Rio de Janeiro, Boulevard 28 de setembro 157/209, Vila Isabel, 20551-030 Rio de Janeiro, RJ, Brasil.
Accepted July 2, 1997
Electronic publication: October, 1998