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root perforation and formocresol pulpotomy
0099-2399/92/1808-0399/$03.00/0 JOURNAL OF ENDODONTICS Copyright © 1992 by The American Association of Endodontists
Printed in U.S.A. VOL. 18, NO. 8, AUGUST1992
CASE REPORT Periodontal Changes following Coronal/Root Perforation and Formocresol Pulpotomy Herbert Abrams, DDS, Charles J. Cunningham, DDS, and Steve B. Lee, DDS
A clinical case report is presented which describes the sequelae of an iatrogenic lateral crown/root perforation and a formocresol pulpotomy. The postoperative course of the initial therapy included significant hard and soft tissue destruction and eventual tooth loss. The possible implication of the role of formocresol is discussed.
the use of formocresol following an iatrogenic crown/root perforation may have contributed to rapid, extensive alveolar bone destruction with eventual loss of the tooth. CASE REPORT A 43-year-old white woman was referred to the University of Kentucky Graduate Periodontics Clinic for evaluation of intermittent discomfort in the maxillary right first premolar area. Past dental history revealed that several months earlier, a large composite restoration was placed in this tooth by her private dentist. Approximately 3 months later, she returned to his office complaining of spontaneous episodes of pain of short duration and "eye aches" on the right side. The restored tooth was tender to percussion. A positive response was obtained with a vitalometer. A diagnosis of"irreversible pulpitis" was made. An emergency pulpotomy was performed. During access preparation, the distal wall of the pulp chamber and/or root was perforated. An attempt was made to seal the iatrogenic defect with gutta-percha. A cotton pellet with formocresol (Buckley's Formula) was placed in the pulp chamber and the access opening was closed with temporary filling material. At this time, the patient was advised that the prognosis of the tooth was poor. Three weeks later, she returned to her dentist for treatment of an acute periodontal abscess in the maxillary right premolar area. The patient presented initially at the Graduate Periodontics Clinic 2 months following the perforation. Her medical history revealed that she was currently taking synthroid (BootsFlint Inc., Licolnshire, IL) for hypothyroidism and Dyazide (Smith Kline & French, Philadelphia, PA) for hypertension. Her blood pressure at this time was 152/110. The patient stated that since the pulpotomy, she has had intermittent discomfort in the involved area. The clinical examination revealed no apparent signs of inflammation in the area. Periodontal probing revealed localized, severe (8 to 10 mm) pocketing on the distal surface of the maxillary right first premolar. The tooth was asymptomatic to palpation and percussion. Radiographic examination revealed a radiolucent area surrounding a large radiopaque object extruding into the interproximal area on the distal aspect of the maxillary first premolar (Fig. 1). Following the clinical examination, it was
Successful endodontic treatment and optimal periradicular healing require thorough instrumentation and disinfection of the root canal system. Cleaning and shaping of the root canal is the primary means of eliminating necrotic tissue and bacteria (1). Historically, intracanal medications have also played an important role in promoting the healing of the periradicular tissue by reducing the bacterial population retained within the pulp space. However, just as the bacteria within an infected pulp can have an adverse effect on the periodontium, so might the medications used in root canal disinfection. Formocresol has been used in dentistry since 1904 with apparent clinical success (2). It contains formaldehyde, an alkylating agent which is highly antimicrobial, and cresol, a protein-coagulating phenolic compound (3). Studies on experimental models have confirmed the tissue irritating and cytotoxic effects of formocresol even in minute amounts (46). These studies have shown that formocresol can diffuse through the apical foramen within minutes of application. It can also be rapidly absorbed into systemic circulation as well as into the surrounding periodontal ligament, bone, and dentin (6). Morse (7) suggests that immunological responses caused by formocresol can result in endodontic flare-ups such as pain, swelling, and bone resorption. Ranley and Boyan (8), using bovine pulp tissue, found that formocresol can cause tissue destruction on contact due to the cresol component. Adverse effects coinciding with clinical use of formocresol have been previously reported (9, 10). In both case reports, formocresol was used as an intracanal medication resulting in significant necrosis of the supporting bone and surrounding tissues. The purpose of this article is to report a case in which .'4QQ
400
Abrams et al.
FiG 1. Radiograph of involved area at time of initial examination.
recommended that the patient return to her physician for reevaluation of her hypertension. Further dental treatment would be postponed until her hypertension was under control. Two weeks later the patient returned to the clinic. Her blood pressure was 126/88. Her physician stated that there were no contraindications for dental treatment, including surgery. In consultation with the patient's referring dentist, it was decided to gain surgical access to this area and evaluate the involved tooth. Anesthesia was accomplished with 1.8 ml of 2% mepivicaine hydrochloride with levonordefrin 1:20,000. Surgical access revealed a large one-walled osseous defect between teeth 4 and 5. A large cone of gutta-percha extruded from the distal aspect of the maxillary right first premolar with periodontal attachment loss at this location (Fig. 2). At this time the prognosis of the tooth was deemed hopeless. The tooth was extracted and minimal osseous recontouring was performed to facilitate flap closure. A gross examination of the extracted tooth confirmed a perforation (3 m m x 6 mm) on the distal aspect of the root extending from the cervical line to the furcation (Fig. 3). A cotton pellet was found within the pulp chamber. The tooth with attached bone and soft tissue was submitted to the oral pathology department for histological examination. The microscopic examination was consistent with the clinical finding of chronic soft tissue inflammation, horizontal and vertical interdental bone loss, and a lateral root defect. The surgical site healed without complications. The patient proceeded with a prosthetic replacement of the extracted tooth. She was not available for follow-up examination.
Journal of Endodontics
FIG 2. Surgical exposure of involved areas, Note gutta-percha protruding from perforation on distal surface (arrow).
DISCUSSION This case report presents the results of an iatrogenic perforation of the distal wall of the pulp chamber/distal aspect of the root of a maxillary right first premolar during root canal therapy. Gutta-percha was used to attempt a seal of the defect and a formocresol pulpotomy was completed at the initial appointment. Because of the size and location of the perforation, it was apparently not possible to obtain an adequate "seal" that would have prevented an interchange of fluids, bacteria, and medicaments between the pulp chamber and oral cavity. A revised treatment plan may have been indicated at this time. Extraction or orthodontic extrusion were apparent options. However, the election was made to perform a formocresol pulpotomy and retain the tooth with root canal therapy included in the treatment regimen. It is the authors' opinion that the subsequent selection of formocresol as the intrachamber medicament contributed to the rapid, severe soft and hard tissue destruction adjacent to the perforation. A formocresol-medicated cotton pellet was placed in the pulp chamber and left for an extended period of time (10 wk). This placement of the medicated cotton pellet allowed the formocresol to be in continuous contact with, or to have unimpeded access to the adjacent tissues. This prolonged exposure time may have been a significant factor in the rapid and extensive tissue destruction. The lateral root perforation alone may have caused a gradual chronic breakdown of the horizontal and vertical interdental osseous tissues. However, it is believed that the addition of the highly cyto-
Vol. 18, No. 8, August 1992
FIG 3. Extracted tooth with perforation. Cotton pellet r e m o v e d from pulp chamber.
toxic formocresol further compromised the situation. The direct contact of the formocresol with the adjacent tissues would permit vascular dissemination of formocresol components (11, 12), a humoral response (13, 14), and coagulation necrosis at the contact site (15). One or more of these response mechanisms may have been a significant factor in the tissue destruction. The tremendous amount of bone loss in a relatively short period of time has not been observed by the authors in perforation cases with other commonly used intracanal medicaments. This phenomenon is similar to previously reported cases (9, 10). The close interrelationship of the dental pulp and the periodontium has been recognized for a long time. Anatomically, there is communication between the pulp and periodontium via the apical foramina, dentinal tubules, and lateral and accessory canals. The fact that formaldehyde preparations cause tissue fixation, inflammation, and necrosis of soft tissue within the root canal leads one to contemplate the effect on the adjacent periodontium. Cases such as this show demonstrable tissue damage. Subclinical changes may occur in cases where direct contact or exposure is not clinically evident. The choice of a less cytotoxic intrapulpal medicament may result in no or minimal effect on the hard and soft tissue. Some insight into this question may come from the periodontal literature regarding osseous grafts. Researchers have reported a difference in the results of new attachment procedures when endodontically treated teeth are compared with teeth not treated with root canal fillings. Early studies by Morris (16) and later by Pritchard (17) indicated that endo-
Formocresol and Periodontal Change
401
dontically obturated teeth may hamper the regeneration of new attachment. Sepe et al. (18) evaluated the healing following freeze-dried bone allografts in human periodontal defects. It was found upon surgical reentry that 60% of the defects adjacent to vital teeth demonstrated bone fill greater than 50%. By comparison, only 33% of the endodontically treated teeth demonstrated an equal amount of regeneration. Similar results were found in a later study by Sanders et al. (19) which evaluated the regenerative capacity of composite freeze-dried bone allografts with and without autogenous bone grafts. These findings make it tempting to speculate that the decreased success of the freeze-dried bone grafts may be due to root canal therapy and/or intracanal medicaments diffusing through exposed dentinal tubules into the periodontium. Based on these studies, it appears that the use of formaldehyde in the form of formocresol may have consequences that affect subsequent therapy. It is the authors' opinion that had orthodontic extrusion been used in an attempt to retain this tooth, formocresol would not be the intracanal medicament of choice. Although it has antimicrobial properties, the intracanal use of formocresol with its fixative properties may in itself cause inflammatory responses in the periradicular tissues (2). Animal studies indicate that the intracanal use of formocresol also results in systemic absorption and may cause tissue changes remote from the site of clinical application (7, 16). Other animal studies report an immune response to formaldehyde fixation of autogenous tissue implants (20) and tissue necrosis of surrounding tissues following similar implants (21). In addition, formaldehyde has been reported to be mutagenic and carcinogenic (2). There is published data indicating that other fixative agents such as gluteraldehyde may be as effective and safer than formaldehyde. Studies by Wemes et al. (5) have compared gluteraldehyde with formaldehyde as an intracanal medicament. They concluded that gluteraldehyde does not penetrate outside the tooth, produces no periapical irritation, and facilitates the mechanical preparation of the root canal. Formocresol has been used in endodontics for over 80 yr and may lead to complacency regarding its biocompatibility relative to other available agents. Dr. Abrams is associate professor and director, Periodontics Graduate Program, University of Kentucky College of Dentistry, Lexington, KY. Dr. Cunningham is professor, Department of Endodontics, University of Florida College of Dentistry, Gainesville, FL. Dr. Lee is a former resident, Periodontics Graduate Program, University of Kentucky College of Dentistry, Lexington, KY and is now in private practice in Fort Wayne, IN. Address requests for reprints to Dr. Herbert Abrams, Department of Oral Health Practice, University of Kentucky College of Dentistry, 800 Rose Street, Lexington, KY 40536-0084.
References 1. Schilder H, Yes FS. Canal debridement and disinfection. In: Cohen S, Burns RC eds. Pathways of the pulp. 3rd ed. St. Louis: CV Mosby, 1984. 2. Sipes R, Binkley CJ. The use of formocresol in dentistry: a review of the literature. Quintessence Int 1986;17:15-6. 3. Spanberg L. Intracanal medication in endodontics. In: Ingle JR, ed. Endodontics. 3rd ed. Philadelphia: Lea & Febiger, 1985:567. 4~ Dankert J, Gravemade EJ, Wemes JC, Diffusion of formocresol and gtutaraldehyde through dentin and cementum. J Endodon 1976;2:42-6. 5. Wemes JC, PurdelI-Lewis D, Jongloed W, Vaalburg W. Diffusion of carbon-14-labeled formocresol and giutaraldehyde in tooth structures. Oral Surg 1982;54:341-6 6. Myers DR, Sheaf KH, Dirksen TR, Pashley DH, Whitford GM, Reynolds KE. Distribution of 14C-formaldehyde after pulpotomy with formocresol. J Am Dent Assoc 1978;96:805-13. 7. Morse DR. Immunologic aspects of pulpal-periapical diseases. Oral Surg 1977;43:436-51.
402
Abrams et al.
8. Ranly DM, Boyan BD. The effect of formocresol on lipids of bovine pulp. J Endodon 1986;12:559-63. 9. Cambreuzzi JV, Greenfield RS. Necrosis of cresta/bone related to the use of excessive formocresol medication dudng endodontic treatment. J Endodon 1983;9:565-7. 10. Kopczyk RA, Cunningham CJ, Abrams H. Periodontal implications of formocresol medication. J Endodon 196;12:567-9. 11. Hata G, Nishikawa I, Kawzor S, Toda T. Systemic distribution of '4£;labeled formaldehyde applied in the root canal following pulpectomy. J Endodon 1989;15:539-43. 12. Block RM, Lewis RD, Hirsch J, Coffey J, Langeland K. Systemic distribution of [14C}-Iabeled paraformaldehyde incorporated within formocresol following pulpotomies in dogs. J Endodon 1983;9:176-89. 13. Block RM, Lewis RD, Sheats JB, Fawley J. Cell-mediated immunity to dog pulp tissue altered by formocresol within the root canal. J Endodon 1977; 3:424. 14. Block RM, Lewis RD, Sheats JB, Burke SH. Cell-mediated immune response to dog pulp tissue altered by 6.5 percent paraformaldehyde via the root canal. J Endodon 1978;4:346.
Journal of Endodontics 15. Robbins SL, Cotran RS, Kumar V. Pathologic basis of disease. 3rd ed. Philadelphia: WB Saunders Co., 1984:15. l & Morris ML. Healing of human periodontal tissues following surgical detachment from non-vital teeth. J Periodonto11957;28:222. 17. Pritchard JF. Advanced periodontal disease: surgical and prosthetic management. 2nd ed. 557. Philadelphia: WB Saunders Co., 1972:557. 18. Sepe WW, Bowers GM, Lawrence JJ, et al. Clinical evaluation of freezedried bone allografts in periodontal osseous defects. Part II. J Pedodonto11978; 49:9-14. 19. Sanders JJ, Sepe WW, Bowers GM, et al. Clinical evaluation of freezedried bone allografts in periodontal osseous defects. Part II1. Composite freezedried bone a,ografts with and without autogenous bone grafts. J Pedodontol 1983; 54:1-7. 20. Thoden vanVelgan SK, Felthamp-Vroom TM. Immunologic consequences of formaldehyde fixation of autogenous tissue implants. J Endodon 1977 ;3:179-85. 21. Brian FD Jr, Ranly DM, Dutton RS, Madden RM. Reaction of rat connective tissue to unfixed and formaldehyde-fixed autogenous implants enclosed in tubes. J Endodon 1980;6:628-35.
A Word for the Wise A time-honored editorial plea which is more often breached than observed is the following, In our opinion, we think that an author when he is writing something should not get accustomed to the habit of making use of too many redundant, repetitious, and unnecessary words that he does not actually really need in order to put his message across to the reader of the article.
Lindsey B. McMaster
Printed in U.S.A. VOL. 18, NO. 8, AUGUST1992
CASE REPORT Periodontal Changes following Coronal/Root Perforation and Formocresol Pulpotomy Herbert Abrams, DDS, Charles J. Cunningham, DDS, and Steve B. Lee, DDS
A clinical case report is presented which describes the sequelae of an iatrogenic lateral crown/root perforation and a formocresol pulpotomy. The postoperative course of the initial therapy included significant hard and soft tissue destruction and eventual tooth loss. The possible implication of the role of formocresol is discussed.
the use of formocresol following an iatrogenic crown/root perforation may have contributed to rapid, extensive alveolar bone destruction with eventual loss of the tooth. CASE REPORT A 43-year-old white woman was referred to the University of Kentucky Graduate Periodontics Clinic for evaluation of intermittent discomfort in the maxillary right first premolar area. Past dental history revealed that several months earlier, a large composite restoration was placed in this tooth by her private dentist. Approximately 3 months later, she returned to his office complaining of spontaneous episodes of pain of short duration and "eye aches" on the right side. The restored tooth was tender to percussion. A positive response was obtained with a vitalometer. A diagnosis of"irreversible pulpitis" was made. An emergency pulpotomy was performed. During access preparation, the distal wall of the pulp chamber and/or root was perforated. An attempt was made to seal the iatrogenic defect with gutta-percha. A cotton pellet with formocresol (Buckley's Formula) was placed in the pulp chamber and the access opening was closed with temporary filling material. At this time, the patient was advised that the prognosis of the tooth was poor. Three weeks later, she returned to her dentist for treatment of an acute periodontal abscess in the maxillary right premolar area. The patient presented initially at the Graduate Periodontics Clinic 2 months following the perforation. Her medical history revealed that she was currently taking synthroid (BootsFlint Inc., Licolnshire, IL) for hypothyroidism and Dyazide (Smith Kline & French, Philadelphia, PA) for hypertension. Her blood pressure at this time was 152/110. The patient stated that since the pulpotomy, she has had intermittent discomfort in the involved area. The clinical examination revealed no apparent signs of inflammation in the area. Periodontal probing revealed localized, severe (8 to 10 mm) pocketing on the distal surface of the maxillary right first premolar. The tooth was asymptomatic to palpation and percussion. Radiographic examination revealed a radiolucent area surrounding a large radiopaque object extruding into the interproximal area on the distal aspect of the maxillary first premolar (Fig. 1). Following the clinical examination, it was
Successful endodontic treatment and optimal periradicular healing require thorough instrumentation and disinfection of the root canal system. Cleaning and shaping of the root canal is the primary means of eliminating necrotic tissue and bacteria (1). Historically, intracanal medications have also played an important role in promoting the healing of the periradicular tissue by reducing the bacterial population retained within the pulp space. However, just as the bacteria within an infected pulp can have an adverse effect on the periodontium, so might the medications used in root canal disinfection. Formocresol has been used in dentistry since 1904 with apparent clinical success (2). It contains formaldehyde, an alkylating agent which is highly antimicrobial, and cresol, a protein-coagulating phenolic compound (3). Studies on experimental models have confirmed the tissue irritating and cytotoxic effects of formocresol even in minute amounts (46). These studies have shown that formocresol can diffuse through the apical foramen within minutes of application. It can also be rapidly absorbed into systemic circulation as well as into the surrounding periodontal ligament, bone, and dentin (6). Morse (7) suggests that immunological responses caused by formocresol can result in endodontic flare-ups such as pain, swelling, and bone resorption. Ranley and Boyan (8), using bovine pulp tissue, found that formocresol can cause tissue destruction on contact due to the cresol component. Adverse effects coinciding with clinical use of formocresol have been previously reported (9, 10). In both case reports, formocresol was used as an intracanal medication resulting in significant necrosis of the supporting bone and surrounding tissues. The purpose of this article is to report a case in which .'4QQ
400
Abrams et al.
FiG 1. Radiograph of involved area at time of initial examination.
recommended that the patient return to her physician for reevaluation of her hypertension. Further dental treatment would be postponed until her hypertension was under control. Two weeks later the patient returned to the clinic. Her blood pressure was 126/88. Her physician stated that there were no contraindications for dental treatment, including surgery. In consultation with the patient's referring dentist, it was decided to gain surgical access to this area and evaluate the involved tooth. Anesthesia was accomplished with 1.8 ml of 2% mepivicaine hydrochloride with levonordefrin 1:20,000. Surgical access revealed a large one-walled osseous defect between teeth 4 and 5. A large cone of gutta-percha extruded from the distal aspect of the maxillary right first premolar with periodontal attachment loss at this location (Fig. 2). At this time the prognosis of the tooth was deemed hopeless. The tooth was extracted and minimal osseous recontouring was performed to facilitate flap closure. A gross examination of the extracted tooth confirmed a perforation (3 m m x 6 mm) on the distal aspect of the root extending from the cervical line to the furcation (Fig. 3). A cotton pellet was found within the pulp chamber. The tooth with attached bone and soft tissue was submitted to the oral pathology department for histological examination. The microscopic examination was consistent with the clinical finding of chronic soft tissue inflammation, horizontal and vertical interdental bone loss, and a lateral root defect. The surgical site healed without complications. The patient proceeded with a prosthetic replacement of the extracted tooth. She was not available for follow-up examination.
Journal of Endodontics
FIG 2. Surgical exposure of involved areas, Note gutta-percha protruding from perforation on distal surface (arrow).
DISCUSSION This case report presents the results of an iatrogenic perforation of the distal wall of the pulp chamber/distal aspect of the root of a maxillary right first premolar during root canal therapy. Gutta-percha was used to attempt a seal of the defect and a formocresol pulpotomy was completed at the initial appointment. Because of the size and location of the perforation, it was apparently not possible to obtain an adequate "seal" that would have prevented an interchange of fluids, bacteria, and medicaments between the pulp chamber and oral cavity. A revised treatment plan may have been indicated at this time. Extraction or orthodontic extrusion were apparent options. However, the election was made to perform a formocresol pulpotomy and retain the tooth with root canal therapy included in the treatment regimen. It is the authors' opinion that the subsequent selection of formocresol as the intrachamber medicament contributed to the rapid, severe soft and hard tissue destruction adjacent to the perforation. A formocresol-medicated cotton pellet was placed in the pulp chamber and left for an extended period of time (10 wk). This placement of the medicated cotton pellet allowed the formocresol to be in continuous contact with, or to have unimpeded access to the adjacent tissues. This prolonged exposure time may have been a significant factor in the rapid and extensive tissue destruction. The lateral root perforation alone may have caused a gradual chronic breakdown of the horizontal and vertical interdental osseous tissues. However, it is believed that the addition of the highly cyto-
Vol. 18, No. 8, August 1992
FIG 3. Extracted tooth with perforation. Cotton pellet r e m o v e d from pulp chamber.
toxic formocresol further compromised the situation. The direct contact of the formocresol with the adjacent tissues would permit vascular dissemination of formocresol components (11, 12), a humoral response (13, 14), and coagulation necrosis at the contact site (15). One or more of these response mechanisms may have been a significant factor in the tissue destruction. The tremendous amount of bone loss in a relatively short period of time has not been observed by the authors in perforation cases with other commonly used intracanal medicaments. This phenomenon is similar to previously reported cases (9, 10). The close interrelationship of the dental pulp and the periodontium has been recognized for a long time. Anatomically, there is communication between the pulp and periodontium via the apical foramina, dentinal tubules, and lateral and accessory canals. The fact that formaldehyde preparations cause tissue fixation, inflammation, and necrosis of soft tissue within the root canal leads one to contemplate the effect on the adjacent periodontium. Cases such as this show demonstrable tissue damage. Subclinical changes may occur in cases where direct contact or exposure is not clinically evident. The choice of a less cytotoxic intrapulpal medicament may result in no or minimal effect on the hard and soft tissue. Some insight into this question may come from the periodontal literature regarding osseous grafts. Researchers have reported a difference in the results of new attachment procedures when endodontically treated teeth are compared with teeth not treated with root canal fillings. Early studies by Morris (16) and later by Pritchard (17) indicated that endo-
Formocresol and Periodontal Change
401
dontically obturated teeth may hamper the regeneration of new attachment. Sepe et al. (18) evaluated the healing following freeze-dried bone allografts in human periodontal defects. It was found upon surgical reentry that 60% of the defects adjacent to vital teeth demonstrated bone fill greater than 50%. By comparison, only 33% of the endodontically treated teeth demonstrated an equal amount of regeneration. Similar results were found in a later study by Sanders et al. (19) which evaluated the regenerative capacity of composite freeze-dried bone allografts with and without autogenous bone grafts. These findings make it tempting to speculate that the decreased success of the freeze-dried bone grafts may be due to root canal therapy and/or intracanal medicaments diffusing through exposed dentinal tubules into the periodontium. Based on these studies, it appears that the use of formaldehyde in the form of formocresol may have consequences that affect subsequent therapy. It is the authors' opinion that had orthodontic extrusion been used in an attempt to retain this tooth, formocresol would not be the intracanal medicament of choice. Although it has antimicrobial properties, the intracanal use of formocresol with its fixative properties may in itself cause inflammatory responses in the periradicular tissues (2). Animal studies indicate that the intracanal use of formocresol also results in systemic absorption and may cause tissue changes remote from the site of clinical application (7, 16). Other animal studies report an immune response to formaldehyde fixation of autogenous tissue implants (20) and tissue necrosis of surrounding tissues following similar implants (21). In addition, formaldehyde has been reported to be mutagenic and carcinogenic (2). There is published data indicating that other fixative agents such as gluteraldehyde may be as effective and safer than formaldehyde. Studies by Wemes et al. (5) have compared gluteraldehyde with formaldehyde as an intracanal medicament. They concluded that gluteraldehyde does not penetrate outside the tooth, produces no periapical irritation, and facilitates the mechanical preparation of the root canal. Formocresol has been used in endodontics for over 80 yr and may lead to complacency regarding its biocompatibility relative to other available agents. Dr. Abrams is associate professor and director, Periodontics Graduate Program, University of Kentucky College of Dentistry, Lexington, KY. Dr. Cunningham is professor, Department of Endodontics, University of Florida College of Dentistry, Gainesville, FL. Dr. Lee is a former resident, Periodontics Graduate Program, University of Kentucky College of Dentistry, Lexington, KY and is now in private practice in Fort Wayne, IN. Address requests for reprints to Dr. Herbert Abrams, Department of Oral Health Practice, University of Kentucky College of Dentistry, 800 Rose Street, Lexington, KY 40536-0084.
References 1. Schilder H, Yes FS. Canal debridement and disinfection. In: Cohen S, Burns RC eds. Pathways of the pulp. 3rd ed. St. Louis: CV Mosby, 1984. 2. Sipes R, Binkley CJ. The use of formocresol in dentistry: a review of the literature. Quintessence Int 1986;17:15-6. 3. Spanberg L. Intracanal medication in endodontics. In: Ingle JR, ed. Endodontics. 3rd ed. Philadelphia: Lea & Febiger, 1985:567. 4~ Dankert J, Gravemade EJ, Wemes JC, Diffusion of formocresol and gtutaraldehyde through dentin and cementum. J Endodon 1976;2:42-6. 5. Wemes JC, PurdelI-Lewis D, Jongloed W, Vaalburg W. Diffusion of carbon-14-labeled formocresol and giutaraldehyde in tooth structures. Oral Surg 1982;54:341-6 6. Myers DR, Sheaf KH, Dirksen TR, Pashley DH, Whitford GM, Reynolds KE. Distribution of 14C-formaldehyde after pulpotomy with formocresol. J Am Dent Assoc 1978;96:805-13. 7. Morse DR. Immunologic aspects of pulpal-periapical diseases. Oral Surg 1977;43:436-51.
402
Abrams et al.
8. Ranly DM, Boyan BD. The effect of formocresol on lipids of bovine pulp. J Endodon 1986;12:559-63. 9. Cambreuzzi JV, Greenfield RS. Necrosis of cresta/bone related to the use of excessive formocresol medication dudng endodontic treatment. J Endodon 1983;9:565-7. 10. Kopczyk RA, Cunningham CJ, Abrams H. Periodontal implications of formocresol medication. J Endodon 196;12:567-9. 11. Hata G, Nishikawa I, Kawzor S, Toda T. Systemic distribution of '4£;labeled formaldehyde applied in the root canal following pulpectomy. J Endodon 1989;15:539-43. 12. Block RM, Lewis RD, Hirsch J, Coffey J, Langeland K. Systemic distribution of [14C}-Iabeled paraformaldehyde incorporated within formocresol following pulpotomies in dogs. J Endodon 1983;9:176-89. 13. Block RM, Lewis RD, Sheats JB, Fawley J. Cell-mediated immunity to dog pulp tissue altered by formocresol within the root canal. J Endodon 1977; 3:424. 14. Block RM, Lewis RD, Sheats JB, Burke SH. Cell-mediated immune response to dog pulp tissue altered by 6.5 percent paraformaldehyde via the root canal. J Endodon 1978;4:346.
Journal of Endodontics 15. Robbins SL, Cotran RS, Kumar V. Pathologic basis of disease. 3rd ed. Philadelphia: WB Saunders Co., 1984:15. l & Morris ML. Healing of human periodontal tissues following surgical detachment from non-vital teeth. J Periodonto11957;28:222. 17. Pritchard JF. Advanced periodontal disease: surgical and prosthetic management. 2nd ed. 557. Philadelphia: WB Saunders Co., 1972:557. 18. Sepe WW, Bowers GM, Lawrence JJ, et al. Clinical evaluation of freezedried bone allografts in periodontal osseous defects. Part II. J Pedodonto11978; 49:9-14. 19. Sanders JJ, Sepe WW, Bowers GM, et al. Clinical evaluation of freezedried bone allografts in periodontal osseous defects. Part II1. Composite freezedried bone a,ografts with and without autogenous bone grafts. J Pedodontol 1983; 54:1-7. 20. Thoden vanVelgan SK, Felthamp-Vroom TM. Immunologic consequences of formaldehyde fixation of autogenous tissue implants. J Endodon 1977 ;3:179-85. 21. Brian FD Jr, Ranly DM, Dutton RS, Madden RM. Reaction of rat connective tissue to unfixed and formaldehyde-fixed autogenous implants enclosed in tubes. J Endodon 1980;6:628-35.
A Word for the Wise A time-honored editorial plea which is more often breached than observed is the following, In our opinion, we think that an author when he is writing something should not get accustomed to the habit of making use of too many redundant, repetitious, and unnecessary words that he does not actually really need in order to put his message across to the reader of the article.
Lindsey B. McMaster