J. Nihon
Univ.
Sch. Dent.,
Vol.
33, 49-53,
1991
49
Surgical Root
Treatment of Paresthesia Following Over-extension of Canal Filling Material: A Case Report Osman Zeki GUMRU, DDS, Ph. D and Serhat YALCIN, DDS, Ph. D.
(Received24 October and accepted15November 1990) Key words:
paresthesia, root canal filling material, mental nerve, endodontic treatment Abstract
A case of paresthesia of the mental nerve following over-extension of root canal filling material into the inferior alveolar canal is presented . The causes of this complication are discussed and the importance of performing surgical treatment as early as possible is emphasized. Introduction The inadvertent introduction of root canal material into the inferior alveolar canal during endodontic treatment can cause problems ranging from mild inflammatory reactions[1,2] to serious neurotoxic complications[3,4]. One such complication is paresthesia or anesthesia in the lower lip. If a resorbable filling material such as iodoform paste has been used, discomfort can be completely eliminatee. However, use of a non-resorbable material leads to long-lasting inconvenience. The filling materials most commonly associated with such complications are those containing paraformaldehyde such as N2[6-9]and endomethasone[10-12]. There are also several reports of problems following the use of AH-26[13-15],Hydron[16], Diaket-A[4], Ribbler's pastes[17], Spad[18] and Endoseal[19]. Some investigators have reported that paresthesia resulting from overextension of root canal filling material into the inferior alveolar canal heals spontaneously with time, but others have stated that surgical decompression facilitates recovery. In this article, we present a case of paresthesia resulting from over-extension of endomethasone, and emphasize the importance of early surgical treatment. Case Report A 43-year-old woman was referred to the Oral Surgery Department complaining of paresthesia of the left lower lip. According to the patient, root canal treatment of the lower left second premolar had been performed using local Faculty of Dentistry, Department of Oral Surgery, University of Istanbul, Istanbul, Turkey . To whom all correspondence should be addressed : Dr. Osman Zeki GUMR U, Istanbul Universitesi Dishekimligi Fakultesi, Agiz, Dis, Cene Hast. ye Cerrahisi Anabilim Dali, Capa, Istanbul, TURKEY.
50
anesthesia one week previously. For root canal treatment, endomethasone had been inserted into the canal using an engine-driven rotary paste filler. No radiographs had been taken. The patient had returned to her dentist several days later, complaining of swelling and numbness. She had received antibiotics, but there was no improvement. On clinical examination, buccal swelling was found to be associated with 5 and the numbness was unchanged. A periapical radiograph showed a large amount of root canal filling material located beyond the apex of 5 with a horizontal extension apparently in the inferior alveolar canal (Fig. 1). It was decided to remove the tooth involved and to decompress the inferior alveolar nerve. Using local anesthesia, a large buccal mucoperiosteal flap was raised to provide access to the inferior alveolar canal. After extraction of the tooth, the inferior alveolar canal was cautiously identified and the nerve was exposed. The tube-like filling material, about 11 mm long and 2.5 mm wide, was found to have covered the nerve. The material removed was white in color. The nerve sheath was open and observed to have been penetrated by the filling material. After the wound had been cleaned, the flap was sutured to its original position. A postoperative periapical radiograph confirmed that the endodontic material in the inferior alveolar canal had been removed completely (Fig. 2). Antibiotic therapy was continued during the first postoperative week. Paresthesia was present one month after surgery. On examination two months later, it was observed that paresthesia had decreased. After four months of post-surgical follow-up, the patient had no complaints of sensory disturbance. Discussion Serious problems such as paresthesia and similar neural complications may occur during endodontic treatment. Such dangers are becoming more common in the treatment of teeth whose apices are close to the inferior alveolar canal. A review of the literature dealing with sensory loss following endodontic treatment reveals that there are three cardinal mechanisms responsible for this condition: 1) Chemical neurotoxicity, 2) Mechanical nerve damage and degeneration caused by compression of filling material in the vicinity of the nerve, 3) Direct damage to the nerve by instrumentation[12,18,20]. BRODINet al. [31stated that chemical neurotoxicity rather than mechanical pressure on the nerve was the probable cause of paresthesia. It has been reported that phenol and its derivatives may penetrate tissue and coagulate protein. Also eugenol, a phenol derivative, is toxic to the nerve and is one of the components of some root canal filling materials[12,19,21,22]. FORMANand ROOD[12] stated that in the case of phenol derivatives applied for a short time, recovery should be immediate, but when in contact with the nerve for several weeks permanent damage is likely to ensue. In many reported cases, the use of N2 or a paraformaldehyde-containing material was involved[6-121. Several studies [13,14,23] have shown that AH-26 is cytotoxic in tissue culture, whereas others[241have found no evidence for this. NEAVERTH[191 reported a case involving
51
the use of Endoseal, an injectable obturating material containing zinc oxide eugenol. As in all cases reported in the literature, inadvertent over-extension can happen even in the hands of the most skilled practitioner. Therefore, when mandibular molars and premolars are treated endodontically, it is recommended that root canal filling materials containing formaldehyde or paraformaldehyde should not be used[11]. It has been reported that severe local compression may crush the nerve fibers, leading to wallerian degeneration, and that recovery from nerve damage depends on the duration and severity of the compression[12]. SPIELMANet al. [15]have mentioned that the effect of mechanical pressure is perceived immediately, whereas the effect of chemical irritation may take several days to appear. MERRILE[25] reported that physical decompression of the nerve facilitates nerve regeneration. GATOTand Tovi[13] investigated direct trauma caused by a rotary filler and mechanical compression of the material in the vicinity of the nerve, and reported the usefulness of steroid therapy in cases of inferior alveolar nerve injury following endodontic overfilling. GIRARD[26] stated that the management of nerve damage, assuming adequate surgical skill, should generally be left to nature. NEAVERTH[19] considered that this type of injury should be identified and that surgery should be instituted as early as possible where indicated. In the present case, it was considered that paresthesia was due to direct damage by instrumentation and local compression by the filling material, and therefore immediate surgical treatment was indicated. The fact that the sensory loss rapidly improved indicates that surgical decompression should be performed as early as possible. References [1] MARAZABAL, M. and ERASQUIN, J.: Responseof periapical tissues in the rat molar to root canal fillingswith Diaket and AH-26, Oral Surg., 21, 786-804,1966 [2] SELTZER, S., SOLTANOFF, W. and SMITH, J.: Biologic aspectsof endodontics.V. Periapical tissue reaction to root canal instrumentationbeyond the apexand root canal filling short of and beyond the apex, Oral Surg., 36, 725-737,1973 [3] BRODIN, P., ROED, A., AARS, H. and ORSTAVEK, D.: Neurotoxiceffectsof root-fillingmaterials on rat phrenic nerve in vitro,J. Dent. Res., 61, 1020-1023,1982 [4] ORSTAVIK, D., BRODIN, P. and Ass, E.: Paresthesiafollowingendodontictreatment:Surveyof the literatureand report of a case,Mt. Endodont. J., 16, 167-172,1983 [5] MANISALI, Y., YUCEL,T. and ERISEN, R.: Overfilling of the root, Oral Surg., 68, 773-775,1989 [6] EHRMAN, E. H.: Root canal treatmentwith N2.An evaluationand case history,Aust. Dent. J., 8, 434-438,1963 [7] GROSSMAN, L. I.: Paresthesiafrom N2 and N2 substitute,Oral Surg., 45, 114-115,1978 [8] ORLAY, H.: Overfillingin root canal treatment:Two accidentswith N2,Br. Dent. J., 120376, 1966 [9] SPANBERG, L. and LANGELAND, K.: Biologiceffectsof dental materials.1. Toxicityof root canal filling materials on HeLa cells in vitro,Oral Surg., 35, 402-414,1973 [10] ERISEN, R., YucEL,T. and Kocicky, S.: Endomethasoneroot canal fillingmaterial in the mandibular canal. A case report., Oral Surg., 63, 343-345,1989 [11] KAUFMAN, A. Y. and ROSENBERG, L.: Paresthesiacaused by endomethasone,J. Endodont., 6, 529-531,1980 [12] FORMAN, G. H. and ROOD, J. P.: Successfulretrievalof endodonticmaterialfrom the inferior
52
alveolar nerve, J. Dent., 5, 47-50, 1977 [13] GATOT,A. and Tovi, F.: Prednisone treatment for injury and compression of inferior alveolar nerve: Report of a case of anesthesia following endodontic overfilling, Oral Surg., 62, 704-706, 1986 [14] TAMSE,A., KAFFE,I., LITTNER, M. M. and KOZLOVSKY, A.: Paresthesia following overextension of AH-26: report of two cases and review of the literature, J. Endodont., 8, 88-90, 1982 [15] SPIELMAN, A., GUTMAN, D. and LAUFER, D.: Anesthesia following endodontic overfilling with AH-26, Oral Surg., 52, 554-556, 1981 [16] PYNER, D. A.: Paresthesia of the inferior alveolar nerve caused by Hydron: a case report, J. Endodont., 6, 527-528, 1980 [17] SPANGBERG, L.: Biologic effects of root canal filling materials. The effect on bone tissue of two formaldehyde-containing root canal filling pastes: N2 and Ribbler's paste, Oral Surg., 38, 934-944, 1974 [18] FOREMAN, P. C.: Adverse tissue reactions following the use of SPAD, Mt. Endodont. J., 15, 184, 1982 [19] NEAVERTH, E. J.: Disabling complications following inadvertent overextension of a root canal filling material, J. Endodont., 15, 135-139, 1989 [20] NITZAN,D. W., STABHOLZ, A. and AZAZ,B.: Concepts of accidental overfilling and overinstrumentation in the mandibular canal during root canal treatment, J. Endodont., 9, 8185, 1983 [21] KOZAM, G.: The effect of eugenol on nerve transmission, Oral Surg., 44, 402-414, 1977 [22] ROWE,A. H. R.: Damage to the inferior dental nerve during or following endodontic treatment, Br. Dent. J., 155, 306-307, 1983 [23] HOHAMED, A. R., YOUNIS, O.and SISKIN, M.: Scanning x-ray microanalysis of root canal sealers, Oral Surg., 48, 558-560, 1979 [24] KAWAHARA, H., YAMAGAMI, A. and NAKAMURA, M.: Biologic testing of dental materials by means of tissue culture, Mt. Dent. J., 18, 443-467, 1968 [25] MERRIL, R. G.: Decompression for inferior alveolar nerve injury, J. Oral Surg., 22, 291-300, 1964 [26] GIRARD,K. R.: Considerations in the management of damage to the mandibular nerve, JADA, 98, 65-71, 1979
53
Fig.
1.
Fig.
2.
Univ.
Sch. Dent.,
Vol.
33, 49-53,
1991
49
Surgical Root
Treatment of Paresthesia Following Over-extension of Canal Filling Material: A Case Report Osman Zeki GUMRU, DDS, Ph. D and Serhat YALCIN, DDS, Ph. D.
(Received24 October and accepted15November 1990) Key words:
paresthesia, root canal filling material, mental nerve, endodontic treatment Abstract
A case of paresthesia of the mental nerve following over-extension of root canal filling material into the inferior alveolar canal is presented . The causes of this complication are discussed and the importance of performing surgical treatment as early as possible is emphasized. Introduction The inadvertent introduction of root canal material into the inferior alveolar canal during endodontic treatment can cause problems ranging from mild inflammatory reactions[1,2] to serious neurotoxic complications[3,4]. One such complication is paresthesia or anesthesia in the lower lip. If a resorbable filling material such as iodoform paste has been used, discomfort can be completely eliminatee. However, use of a non-resorbable material leads to long-lasting inconvenience. The filling materials most commonly associated with such complications are those containing paraformaldehyde such as N2[6-9]and endomethasone[10-12]. There are also several reports of problems following the use of AH-26[13-15],Hydron[16], Diaket-A[4], Ribbler's pastes[17], Spad[18] and Endoseal[19]. Some investigators have reported that paresthesia resulting from overextension of root canal filling material into the inferior alveolar canal heals spontaneously with time, but others have stated that surgical decompression facilitates recovery. In this article, we present a case of paresthesia resulting from over-extension of endomethasone, and emphasize the importance of early surgical treatment. Case Report A 43-year-old woman was referred to the Oral Surgery Department complaining of paresthesia of the left lower lip. According to the patient, root canal treatment of the lower left second premolar had been performed using local Faculty of Dentistry, Department of Oral Surgery, University of Istanbul, Istanbul, Turkey . To whom all correspondence should be addressed : Dr. Osman Zeki GUMR U, Istanbul Universitesi Dishekimligi Fakultesi, Agiz, Dis, Cene Hast. ye Cerrahisi Anabilim Dali, Capa, Istanbul, TURKEY.
50
anesthesia one week previously. For root canal treatment, endomethasone had been inserted into the canal using an engine-driven rotary paste filler. No radiographs had been taken. The patient had returned to her dentist several days later, complaining of swelling and numbness. She had received antibiotics, but there was no improvement. On clinical examination, buccal swelling was found to be associated with 5 and the numbness was unchanged. A periapical radiograph showed a large amount of root canal filling material located beyond the apex of 5 with a horizontal extension apparently in the inferior alveolar canal (Fig. 1). It was decided to remove the tooth involved and to decompress the inferior alveolar nerve. Using local anesthesia, a large buccal mucoperiosteal flap was raised to provide access to the inferior alveolar canal. After extraction of the tooth, the inferior alveolar canal was cautiously identified and the nerve was exposed. The tube-like filling material, about 11 mm long and 2.5 mm wide, was found to have covered the nerve. The material removed was white in color. The nerve sheath was open and observed to have been penetrated by the filling material. After the wound had been cleaned, the flap was sutured to its original position. A postoperative periapical radiograph confirmed that the endodontic material in the inferior alveolar canal had been removed completely (Fig. 2). Antibiotic therapy was continued during the first postoperative week. Paresthesia was present one month after surgery. On examination two months later, it was observed that paresthesia had decreased. After four months of post-surgical follow-up, the patient had no complaints of sensory disturbance. Discussion Serious problems such as paresthesia and similar neural complications may occur during endodontic treatment. Such dangers are becoming more common in the treatment of teeth whose apices are close to the inferior alveolar canal. A review of the literature dealing with sensory loss following endodontic treatment reveals that there are three cardinal mechanisms responsible for this condition: 1) Chemical neurotoxicity, 2) Mechanical nerve damage and degeneration caused by compression of filling material in the vicinity of the nerve, 3) Direct damage to the nerve by instrumentation[12,18,20]. BRODINet al. [31stated that chemical neurotoxicity rather than mechanical pressure on the nerve was the probable cause of paresthesia. It has been reported that phenol and its derivatives may penetrate tissue and coagulate protein. Also eugenol, a phenol derivative, is toxic to the nerve and is one of the components of some root canal filling materials[12,19,21,22]. FORMANand ROOD[12] stated that in the case of phenol derivatives applied for a short time, recovery should be immediate, but when in contact with the nerve for several weeks permanent damage is likely to ensue. In many reported cases, the use of N2 or a paraformaldehyde-containing material was involved[6-121. Several studies [13,14,23] have shown that AH-26 is cytotoxic in tissue culture, whereas others[241have found no evidence for this. NEAVERTH[191 reported a case involving
51
the use of Endoseal, an injectable obturating material containing zinc oxide eugenol. As in all cases reported in the literature, inadvertent over-extension can happen even in the hands of the most skilled practitioner. Therefore, when mandibular molars and premolars are treated endodontically, it is recommended that root canal filling materials containing formaldehyde or paraformaldehyde should not be used[11]. It has been reported that severe local compression may crush the nerve fibers, leading to wallerian degeneration, and that recovery from nerve damage depends on the duration and severity of the compression[12]. SPIELMANet al. [15]have mentioned that the effect of mechanical pressure is perceived immediately, whereas the effect of chemical irritation may take several days to appear. MERRILE[25] reported that physical decompression of the nerve facilitates nerve regeneration. GATOTand Tovi[13] investigated direct trauma caused by a rotary filler and mechanical compression of the material in the vicinity of the nerve, and reported the usefulness of steroid therapy in cases of inferior alveolar nerve injury following endodontic overfilling. GIRARD[26] stated that the management of nerve damage, assuming adequate surgical skill, should generally be left to nature. NEAVERTH[19] considered that this type of injury should be identified and that surgery should be instituted as early as possible where indicated. In the present case, it was considered that paresthesia was due to direct damage by instrumentation and local compression by the filling material, and therefore immediate surgical treatment was indicated. The fact that the sensory loss rapidly improved indicates that surgical decompression should be performed as early as possible. References [1] MARAZABAL, M. and ERASQUIN, J.: Responseof periapical tissues in the rat molar to root canal fillingswith Diaket and AH-26, Oral Surg., 21, 786-804,1966 [2] SELTZER, S., SOLTANOFF, W. and SMITH, J.: Biologic aspectsof endodontics.V. Periapical tissue reaction to root canal instrumentationbeyond the apexand root canal filling short of and beyond the apex, Oral Surg., 36, 725-737,1973 [3] BRODIN, P., ROED, A., AARS, H. and ORSTAVEK, D.: Neurotoxiceffectsof root-fillingmaterials on rat phrenic nerve in vitro,J. Dent. Res., 61, 1020-1023,1982 [4] ORSTAVIK, D., BRODIN, P. and Ass, E.: Paresthesiafollowingendodontictreatment:Surveyof the literatureand report of a case,Mt. Endodont. J., 16, 167-172,1983 [5] MANISALI, Y., YUCEL,T. and ERISEN, R.: Overfilling of the root, Oral Surg., 68, 773-775,1989 [6] EHRMAN, E. H.: Root canal treatmentwith N2.An evaluationand case history,Aust. Dent. J., 8, 434-438,1963 [7] GROSSMAN, L. I.: Paresthesiafrom N2 and N2 substitute,Oral Surg., 45, 114-115,1978 [8] ORLAY, H.: Overfillingin root canal treatment:Two accidentswith N2,Br. Dent. J., 120376, 1966 [9] SPANBERG, L. and LANGELAND, K.: Biologiceffectsof dental materials.1. Toxicityof root canal filling materials on HeLa cells in vitro,Oral Surg., 35, 402-414,1973 [10] ERISEN, R., YucEL,T. and Kocicky, S.: Endomethasoneroot canal fillingmaterial in the mandibular canal. A case report., Oral Surg., 63, 343-345,1989 [11] KAUFMAN, A. Y. and ROSENBERG, L.: Paresthesiacaused by endomethasone,J. Endodont., 6, 529-531,1980 [12] FORMAN, G. H. and ROOD, J. P.: Successfulretrievalof endodonticmaterialfrom the inferior
52
alveolar nerve, J. Dent., 5, 47-50, 1977 [13] GATOT,A. and Tovi, F.: Prednisone treatment for injury and compression of inferior alveolar nerve: Report of a case of anesthesia following endodontic overfilling, Oral Surg., 62, 704-706, 1986 [14] TAMSE,A., KAFFE,I., LITTNER, M. M. and KOZLOVSKY, A.: Paresthesia following overextension of AH-26: report of two cases and review of the literature, J. Endodont., 8, 88-90, 1982 [15] SPIELMAN, A., GUTMAN, D. and LAUFER, D.: Anesthesia following endodontic overfilling with AH-26, Oral Surg., 52, 554-556, 1981 [16] PYNER, D. A.: Paresthesia of the inferior alveolar nerve caused by Hydron: a case report, J. Endodont., 6, 527-528, 1980 [17] SPANGBERG, L.: Biologic effects of root canal filling materials. The effect on bone tissue of two formaldehyde-containing root canal filling pastes: N2 and Ribbler's paste, Oral Surg., 38, 934-944, 1974 [18] FOREMAN, P. C.: Adverse tissue reactions following the use of SPAD, Mt. Endodont. J., 15, 184, 1982 [19] NEAVERTH, E. J.: Disabling complications following inadvertent overextension of a root canal filling material, J. Endodont., 15, 135-139, 1989 [20] NITZAN,D. W., STABHOLZ, A. and AZAZ,B.: Concepts of accidental overfilling and overinstrumentation in the mandibular canal during root canal treatment, J. Endodont., 9, 8185, 1983 [21] KOZAM, G.: The effect of eugenol on nerve transmission, Oral Surg., 44, 402-414, 1977 [22] ROWE,A. H. R.: Damage to the inferior dental nerve during or following endodontic treatment, Br. Dent. J., 155, 306-307, 1983 [23] HOHAMED, A. R., YOUNIS, O.and SISKIN, M.: Scanning x-ray microanalysis of root canal sealers, Oral Surg., 48, 558-560, 1979 [24] KAWAHARA, H., YAMAGAMI, A. and NAKAMURA, M.: Biologic testing of dental materials by means of tissue culture, Mt. Dent. J., 18, 443-467, 1968 [25] MERRIL, R. G.: Decompression for inferior alveolar nerve injury, J. Oral Surg., 22, 291-300, 1964 [26] GIRARD,K. R.: Considerations in the management of damage to the mandibular nerve, JADA, 98, 65-71, 1979
53
Fig.
1.
Fig.
2.
