Effects of systemic cortisone on the healing of tooth sockets in rats A histologic
study
R. J. Smales, M.D.S., F.D.S.R.C.S.,* UNIVERSITY
Adelaide, Australia
OF ADELAIDE
Young male rats were divided randomly into experimental and control groups of twenty-seven each. Animals in the experimental group received daily subcutaneous injections of cortisone, in dosages sufficient to allow only slight gains in weight during the 3%day study period, whereas animals in the control group received a similar volume of saline solution. All injections were started 3 days before the upper right first molars were extracted. Histologic evaluation of the sockets of animals killed at intervals during healing showed no significant differences between the experimental and control groups.
Twhenhesuch influence of corticosteroids on wound healing in man is still uncertain, especially healing is complicated by infection. 1Poor healing after general surgical procedures has been reported,2and delayed healing of oral wounds and severe infection have been associated with concurrent corticosteroid tberapy,3-5 although this may not be usual.6 Two studies in rats by other investigators were not conclusive becauseof the experimental methods used.‘, * Shafer’ began systemic cortisone therapy at the time of tooth extraction, whereasHars and Massler* applied corticosteroids topically to the blood clots. This study investigatesthe effects of systemiccortisone in “low” doseson the healing of tooth sockets in rats. METHODS AND MATERIALS
White male rats, 6 to 8 weeks old, from the Wistar colony of the Otago University Animal Breeding Station were divided randomly into nine groups of six each. Three animals from each group received daily subcutaneousinjections of cortisone,? 25 to 30 *Senior Lecturer, Department of Restorative Dentistry. t 17-alpha-hydroxy- I I-dehydrocorticosterone acetate, CIBA Pharmaceuticals, St. Leonards, New South Wales, Australia. 0030-4220/78/0545-0685$00.40/O
0
1978 The C. V. Mosby Co.
685
686
Smales
Oral Surg. May. 1978
mg. per kilogram of body weight, whereas three control animals received a similar volume of 0.85 per cent sterile saline solution. An initial pilot study determinedthe effects of various dosagesof cortisone and tooth extractions on changesin body weight. The final dosage of cortisone selected allowed only slight gains in weight during the total study period of 38 days, thus indicating that this dosagecould be considered “low .” All injections were started3 days before extraction of the upper right first molars, with the animals under pentobarbitone sodium anesthesia.An overdoseof anestheticwas used to kill the animals at 3, 5, 7, 10, 14, 19, 25, 31, and 38 days after extraction. After the rats were decapitated, the right maxillas were placed in 10 per cent neutral buffered formalin solution for 10 days, and then decalcified in 10 per cent formic acid solution. After tissue processing, 5-micron sectionswere cut buccopalatally at lOO-micron intervals along the sockets,and then stainedwith either Harris’ hematoxylin and 1 per cent phloxine or Curtis’ ponceau substitute for Van Gieson.g RESULTS
There were no significant histologic differences in socket healing between the two groups. The cortisone-injected animals were smaller, less active, and had rougher fur than the saline-injected controls, By 3 days after extraction the blood clot was being replaced by granulation tissue, epithelium was beginning to proliferate, and osteoclast activity was present along the crests and margins of the socket. By 5 days most of the clot had been organized by young fibrous connective tissue, epithelium had almost covered the socket, and osteoid was present at the base of the socket. By 10 days keratinized epithelium had covered the socket where osteoid was being replaced by irregular bony trabeculae. By 29 days the socket was filled with irregular lamellar bone trabeculae, and some bone remodelling was occurring. By 31 days haversian systems were present, marrow spaceswere smaller, and the original socket walls had become indistinct. By 38 days further bone remodelling had led to a smooth dense surface over the alveolar crest and original socket. DISCUSSION
The general sequenceof events during socket healing was similar to that describedby other authors in normal rats’, 8*lo and in man.*l, l2 Shafer7found only slight differences from normal in socket healing after 10 days, despite a marked loss of weight shown by his cortisone-injected rats. “The chief defect did not appear in the new bone formation in the sockets but rather as a retardation of maturation of the connective tissue replacement, slow re-epithelialization of the wound, and a prolonging of the sequestrationprocessand its associatedinflammatory reaction.” However, Hars and Massler,8 in their study of topically applied cortisone and prednisolone, found that, comparedwith the control rats, “filling in of the socket with trabecular bone was significantly delayed, new bone formation in the fundic portion of the socket being delayed until after the tenth day. There were no effects evident upon the epithelium and subepithelial connective tissue.”
Systemic cortisone and healing of tooth sockets
687
The different results found between these two studies and the present study of socket healing in rats were probably related to the different concentrations of corticosteroids present within the extraction wounds. Delayed healing and wound infection in dental patients have been described as occurring with daily dosages of corticosteroids equivalent to approximately 25 to 90 mg. of cortisone.3-5 The usual symptom-suppressive dosages used for the treatment of patients with chronic medical conditions are equivalent to about 50 mg. of cortisone daily. However, in some acute life-threatening conditions, short-term dosages may be equivalent to approximately 400 mg. or more of cortisone daily.13 Rats appear to be much more resistant to the effects of corticosteroids on wound healing than is man, since even an obvious reduction in normal gain in weight by the young rats, on cortisone dosages of 25 to 30 mg. per kilogram of body weight, had no significant effects on socket healing in the present study. In some instances tooth extraction may precipitate an adrenal crisis in patients who are, or who have been recently, receiving systemic corticosteroid therapy.14 The stress associated with the daily reception of cortisone injections by the experimental group of rats in the present study did not appear to have any severe effects on them, and all survived the study period. However, precautions should be taken to avoid possible complications of delayed socket healing and infection and the side effects of stress in patients receiving prolonged, high dosages of corticosteroids. In dentistry, systemic and topical corticosteroids should be limited to definite indications for their use. They should be given in low dosages for short periods in most instances. SUMMARY
AND CONCLUSIONS
The effect of systemic cortisone on the healing of tooth sockets in rats was assessed histologically. There were no significant differences between the experimental and control animals. Healing of the sockets in general corresponded with the normal findings of other authors. This study was conducted with the guidance of Professor F. R. Shroff, former head of the Departmentof Basic Dental Sciences, The University of Otago. The technical assistance received from Miss N. Taylor, Miss A. Hoyle, and Mr. J. Koning is also gratefully acknowledged. REFERENCES
1. Cope, C. L.: Adrenal Steroids and Disease, ed. 2, London, 1972, Pitman Medical, pp. 533-556. 2. Green, J. P.: Steroid Therapy and Wound Healing in Surgical Patients, Br. J. Surg. 52: 523-525, 196.5. 3. Doolen, D. E.: Delayed Healing Due to Cortisone Therapy, Dent. Digest 58: 154-155, 1952. 4. Mason, D. A.: Steroid Therapy and Dental Infection. Case Report, Br. Dent. J. 128: 271-274, 1970. 5. Moskow, B. S., Crikelair, G. F., and Wheaton, E. A.: Severe Oral Infection Associated With Prolonged Steroid Therapy. Report of a Case, ORAL SURG. 34: 590-602, 1972. 6. Greenfield, W., and Caruso, W. A.: Systemic Use of Steroids Following Office Oral Surgery, N. Y. State
Dent. J. 42: 482-485, 1976. 7. Shafer, W. G.: The Effect of Cortisone on the Healing of Extraction Wounds in the Rat, J. Dent. Res. 33: 4-11, 1954. 8. Hars, E., and Massler, M.: Effects of Fluorides, Corticosteroids and Tetracyclines on Extraction Wound Healing in Rats, Acta Odontol. Stand. 30: 51 l-522, 1972. 9. Curtis. F.: Me’thode de coloration elective du tissu conjunctif, C. R. Sot. Biol. (Paris) 58: 1038-1040, 190.5.
688
Oral Surg. May, 1978
Smales
10. Huebsch, R. F., Coleman, R. D., Frandsen,A. M., and Becks, H.: The Healing ProcessFollowing Molar Extraction. I. Normal Male Rats (Long-Evans Strain), ORAL SURG. 5: 864-876, 1952. 11. Mangos, J. F.: The Healing of Extraction Wounds. An Experimental Study Based on Microscopic and Radiographic Investigations, N. Z. Dent. J. 37: 4-23, 1941. 12. Amler, M. H., Johnson, P. L., and Salman, I.: Histological and Histochemical Investigation of Human Alveolar Socket Healing in Undisturbed Extraction Wounds, J. Am. Dent. Assoc. 61: 32-44, 1960. 13. Goodman, L. S., and Gilman, A.: The PharmacologicalBasis of Therapeutics, ed. 4, London, 1970, The Macmillan Company, pp. 1629-1635. 14. Cawson, R. A., and James,J.: Adrenal Crisis in a Dental Patient Having Systemic Cotticosteroids, Br. J. Oral Surg. 10: 305-309, 1973. Reprint requests to:
Dr. R. J. Smales Deparment of Restorative Dentistry The University of Adelaide G.P.O. Box 498 Adelaide, South Australia 5001
COPYRIGHT INFORMATION The appearance of a code at the bottom of the first page of an original article in this journal indicates the copyright owner’s consent that copies of the article may be made for personal or internal use, or for the personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc., P.O. Box 76.5, Schenectady, N. Y. 12301, 518-3744430, for copying beyond that permitted by Sections 107 or 108 of the U. S. Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale.
study
R. J. Smales, M.D.S., F.D.S.R.C.S.,* UNIVERSITY
Adelaide, Australia
OF ADELAIDE
Young male rats were divided randomly into experimental and control groups of twenty-seven each. Animals in the experimental group received daily subcutaneous injections of cortisone, in dosages sufficient to allow only slight gains in weight during the 3%day study period, whereas animals in the control group received a similar volume of saline solution. All injections were started 3 days before the upper right first molars were extracted. Histologic evaluation of the sockets of animals killed at intervals during healing showed no significant differences between the experimental and control groups.
Twhenhesuch influence of corticosteroids on wound healing in man is still uncertain, especially healing is complicated by infection. 1Poor healing after general surgical procedures has been reported,2and delayed healing of oral wounds and severe infection have been associated with concurrent corticosteroid tberapy,3-5 although this may not be usual.6 Two studies in rats by other investigators were not conclusive becauseof the experimental methods used.‘, * Shafer’ began systemic cortisone therapy at the time of tooth extraction, whereasHars and Massler* applied corticosteroids topically to the blood clots. This study investigatesthe effects of systemiccortisone in “low” doseson the healing of tooth sockets in rats. METHODS AND MATERIALS
White male rats, 6 to 8 weeks old, from the Wistar colony of the Otago University Animal Breeding Station were divided randomly into nine groups of six each. Three animals from each group received daily subcutaneousinjections of cortisone,? 25 to 30 *Senior Lecturer, Department of Restorative Dentistry. t 17-alpha-hydroxy- I I-dehydrocorticosterone acetate, CIBA Pharmaceuticals, St. Leonards, New South Wales, Australia. 0030-4220/78/0545-0685$00.40/O
0
1978 The C. V. Mosby Co.
685
686
Smales
Oral Surg. May. 1978
mg. per kilogram of body weight, whereas three control animals received a similar volume of 0.85 per cent sterile saline solution. An initial pilot study determinedthe effects of various dosagesof cortisone and tooth extractions on changesin body weight. The final dosage of cortisone selected allowed only slight gains in weight during the total study period of 38 days, thus indicating that this dosagecould be considered “low .” All injections were started3 days before extraction of the upper right first molars, with the animals under pentobarbitone sodium anesthesia.An overdoseof anestheticwas used to kill the animals at 3, 5, 7, 10, 14, 19, 25, 31, and 38 days after extraction. After the rats were decapitated, the right maxillas were placed in 10 per cent neutral buffered formalin solution for 10 days, and then decalcified in 10 per cent formic acid solution. After tissue processing, 5-micron sectionswere cut buccopalatally at lOO-micron intervals along the sockets,and then stainedwith either Harris’ hematoxylin and 1 per cent phloxine or Curtis’ ponceau substitute for Van Gieson.g RESULTS
There were no significant histologic differences in socket healing between the two groups. The cortisone-injected animals were smaller, less active, and had rougher fur than the saline-injected controls, By 3 days after extraction the blood clot was being replaced by granulation tissue, epithelium was beginning to proliferate, and osteoclast activity was present along the crests and margins of the socket. By 5 days most of the clot had been organized by young fibrous connective tissue, epithelium had almost covered the socket, and osteoid was present at the base of the socket. By 10 days keratinized epithelium had covered the socket where osteoid was being replaced by irregular bony trabeculae. By 29 days the socket was filled with irregular lamellar bone trabeculae, and some bone remodelling was occurring. By 31 days haversian systems were present, marrow spaceswere smaller, and the original socket walls had become indistinct. By 38 days further bone remodelling had led to a smooth dense surface over the alveolar crest and original socket. DISCUSSION
The general sequenceof events during socket healing was similar to that describedby other authors in normal rats’, 8*lo and in man.*l, l2 Shafer7found only slight differences from normal in socket healing after 10 days, despite a marked loss of weight shown by his cortisone-injected rats. “The chief defect did not appear in the new bone formation in the sockets but rather as a retardation of maturation of the connective tissue replacement, slow re-epithelialization of the wound, and a prolonging of the sequestrationprocessand its associatedinflammatory reaction.” However, Hars and Massler,8 in their study of topically applied cortisone and prednisolone, found that, comparedwith the control rats, “filling in of the socket with trabecular bone was significantly delayed, new bone formation in the fundic portion of the socket being delayed until after the tenth day. There were no effects evident upon the epithelium and subepithelial connective tissue.”
Systemic cortisone and healing of tooth sockets
687
The different results found between these two studies and the present study of socket healing in rats were probably related to the different concentrations of corticosteroids present within the extraction wounds. Delayed healing and wound infection in dental patients have been described as occurring with daily dosages of corticosteroids equivalent to approximately 25 to 90 mg. of cortisone.3-5 The usual symptom-suppressive dosages used for the treatment of patients with chronic medical conditions are equivalent to about 50 mg. of cortisone daily. However, in some acute life-threatening conditions, short-term dosages may be equivalent to approximately 400 mg. or more of cortisone daily.13 Rats appear to be much more resistant to the effects of corticosteroids on wound healing than is man, since even an obvious reduction in normal gain in weight by the young rats, on cortisone dosages of 25 to 30 mg. per kilogram of body weight, had no significant effects on socket healing in the present study. In some instances tooth extraction may precipitate an adrenal crisis in patients who are, or who have been recently, receiving systemic corticosteroid therapy.14 The stress associated with the daily reception of cortisone injections by the experimental group of rats in the present study did not appear to have any severe effects on them, and all survived the study period. However, precautions should be taken to avoid possible complications of delayed socket healing and infection and the side effects of stress in patients receiving prolonged, high dosages of corticosteroids. In dentistry, systemic and topical corticosteroids should be limited to definite indications for their use. They should be given in low dosages for short periods in most instances. SUMMARY
AND CONCLUSIONS
The effect of systemic cortisone on the healing of tooth sockets in rats was assessed histologically. There were no significant differences between the experimental and control animals. Healing of the sockets in general corresponded with the normal findings of other authors. This study was conducted with the guidance of Professor F. R. Shroff, former head of the Departmentof Basic Dental Sciences, The University of Otago. The technical assistance received from Miss N. Taylor, Miss A. Hoyle, and Mr. J. Koning is also gratefully acknowledged. REFERENCES
1. Cope, C. L.: Adrenal Steroids and Disease, ed. 2, London, 1972, Pitman Medical, pp. 533-556. 2. Green, J. P.: Steroid Therapy and Wound Healing in Surgical Patients, Br. J. Surg. 52: 523-525, 196.5. 3. Doolen, D. E.: Delayed Healing Due to Cortisone Therapy, Dent. Digest 58: 154-155, 1952. 4. Mason, D. A.: Steroid Therapy and Dental Infection. Case Report, Br. Dent. J. 128: 271-274, 1970. 5. Moskow, B. S., Crikelair, G. F., and Wheaton, E. A.: Severe Oral Infection Associated With Prolonged Steroid Therapy. Report of a Case, ORAL SURG. 34: 590-602, 1972. 6. Greenfield, W., and Caruso, W. A.: Systemic Use of Steroids Following Office Oral Surgery, N. Y. State
Dent. J. 42: 482-485, 1976. 7. Shafer, W. G.: The Effect of Cortisone on the Healing of Extraction Wounds in the Rat, J. Dent. Res. 33: 4-11, 1954. 8. Hars, E., and Massler, M.: Effects of Fluorides, Corticosteroids and Tetracyclines on Extraction Wound Healing in Rats, Acta Odontol. Stand. 30: 51 l-522, 1972. 9. Curtis. F.: Me’thode de coloration elective du tissu conjunctif, C. R. Sot. Biol. (Paris) 58: 1038-1040, 190.5.
688
Oral Surg. May, 1978
Smales
10. Huebsch, R. F., Coleman, R. D., Frandsen,A. M., and Becks, H.: The Healing ProcessFollowing Molar Extraction. I. Normal Male Rats (Long-Evans Strain), ORAL SURG. 5: 864-876, 1952. 11. Mangos, J. F.: The Healing of Extraction Wounds. An Experimental Study Based on Microscopic and Radiographic Investigations, N. Z. Dent. J. 37: 4-23, 1941. 12. Amler, M. H., Johnson, P. L., and Salman, I.: Histological and Histochemical Investigation of Human Alveolar Socket Healing in Undisturbed Extraction Wounds, J. Am. Dent. Assoc. 61: 32-44, 1960. 13. Goodman, L. S., and Gilman, A.: The PharmacologicalBasis of Therapeutics, ed. 4, London, 1970, The Macmillan Company, pp. 1629-1635. 14. Cawson, R. A., and James,J.: Adrenal Crisis in a Dental Patient Having Systemic Cotticosteroids, Br. J. Oral Surg. 10: 305-309, 1973. Reprint requests to:
Dr. R. J. Smales Deparment of Restorative Dentistry The University of Adelaide G.P.O. Box 498 Adelaide, South Australia 5001
COPYRIGHT INFORMATION The appearance of a code at the bottom of the first page of an original article in this journal indicates the copyright owner’s consent that copies of the article may be made for personal or internal use, or for the personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc., P.O. Box 76.5, Schenectady, N. Y. 12301, 518-3744430, for copying beyond that permitted by Sections 107 or 108 of the U. S. Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale.
