CLINICAL
n
REPORl-S
Margaret Brady, PhD, RN, CPNP California State University, Long Beach Department of Nursing
n
Margaret Crey, Dr PH, RN, CPNP University of Pennsylvania School of Nursing Philadelphia, Pennsylvania
The Treatment of Avulsed Teeth f’aul
K. Kramer,
C
hildren are the group that most often experience a traumatic accidental injury called tooth avulsion. This problem affects 1 in every 200 school-aged children, and injury can occur at home, in school, or during play and sports activities. The consequences of this accident can be serious, and a child may suffer with them for the rest of his or her life. Nearly all avulsed teeth (there are over 2 million each year in the United States) can be saved by a procedure called replantation. This procedure is recommended by the American Dental Association (1984) and by the American Association of Endodontists (1983). For replantation to be successful, however, the manner in which the avulsed tooth is handled before replantation is crucial. This paper will discuss methods for handling avulsed teeth before replantation to prepare health care providers for an accident involving tooth avulsion. n RATIONALE FOR AVULSED TOOTH REPLANTATION
Dental research has shown that almost any tooth that has been avulsed can be replanted and will be retained permanently (Andreasen & Kristerson, 1981a; Blomlof, 1981b, 1981~; Seltzer & Krasner, 1988). When a tooth is avulsed from its socket, the periodontal ligament that joins the tooth to the bon! socket is ripped in half; half remains on the socket wall, and the other halfremains attached to the tooth (Fig. 1). The portion left in the socket remains viable with no additional treatment because it is bathed in the blood that fills the socket. The problem area is the portion of the ligament that remains on the tooth root. If this portion of the ligament remains viable Paul R. Krasner of Dentistry.
86
is Clinical
Associate
Professor,
Temple
Unwersity
School
n
LIDS
when the tooth is replanted, the ligament will reattach to the periodontal ligament fibers remaining in the socket and can be retained permanently. All treatment must therefore focus on maintaining the viability of the periodontal ligament that is still attached to the tooth (Andreasen, 1975, 1981 b; Cvek, Granath, & Hollender, 1975). The viability of the periodontal ligament can be enhanced by prcventing crushing of the cells of the ligament (Andreasen & Kristerson, 1981a; Hammarstrom, Pierce, Blomlof, Feiglin, & Lindskog, 1986) and by preventing dissolution of the normal cell composition and metabolism of these cells (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al.. 1986). Whatever treatment is used to save an avulsed tooth should attempt to create an environment that simulates as closely as possible the original tooth socket. The best way to create such an environment is by placing the tooth back into the socket immediately (Andreasen & Hjrting-Hansen, 1966a, 1966b; Andreasen & Kristerson, 1981b). If the tooth is rcplanted within 15 to 30 minutes of the accident, there is more than a 90% chance that the tooth will be retained permanently (Andreasen & HjrtingHansen, 1966a, 1966b). After 30 minutes, sufficient numbers of periodontal ligament cells on the root will die so that the possibility of successful ligament reattachment diminishes rapidly (Fig. 2). n
TREATMENT OF THE AVULSED TOOTH
If the avulsed tooth is not placed back into its socket immediately, there still may be a significant chance that the tooth can be retained successhlly after replantation (Andreasen, et al., 1978; Blomlof, 1981a, 198 1b). Whether replantation is successful depends almost totally on how the tooth is stored, preserved,
JOURNAL.
OF PtDlATKlC
HEALTH
CAR1
Journal of Pediatric Health
Patient Management
Care
Severed
k;;;‘J
Socket
Pulo 1
Exchange
87
of Avulsed Tooth
-
t
Normal Tooth
Tooth Being Avulsed n
n
TABLE n
. . . . .
1 Tooth preservation
FIGURE 1 Anatomy
media
Dry media (toilet tissue or gauze) Tap water Sterile saline solution Saliva Milk pH-balanced, cell-preserving fluids (Eagle’s medium or Hank’s solution)
and handled. The media chosen for storage and preservation should be compatible with the tooth root cells. The storage options are shown in Table 1. n
STORAGE MEDIA OPTIONS
The worst storage medium is a drying medium such as toilet tissue or gauze (Andreasen, 1975, 1980, 1981b; Andreasen & Kristerson, 1981b; Blomlof, 1981b). These types of media will dry out the periodontal ligament cells and cause immediate cell death. Allowing the tooth to air-dry or soaking the tooth in tap water is equally destructive. All of these methods of storage should be avoided. Sterile saline solution is also damaging to the tooth cells if the avulsed tooth is allowed to soak in the solution for more than 1 to 2 hours (Blomlof, 1981a, 1981b; Blomlof & Otteskog, 1980). Saline solution
Avulsed
Tooth3
of tooth avuision.
lacks the essential nutrients Mg’ +, Ca’ +, and glucose, which are necessary to replenish nutrients used by the normal metabolic process of the periodontal ligament cells (Blomlof, 1981b; Blomlof & Otteskog, 1980). Saliva can be used as a storage medium for short periods of time. Saliva can be damaging to the tooth cells, however, if avulsed teeth are soaked in it for more than 1 hour (Blomlof, 1981a, 1981b; Blomlof & Otteskog, 1980). Saliva also contaminates the tooth with bacteria (Hammarstrom, et al., 1986). The tooth can be placed under the tongue of the accident victim; however, there is a danger that the tooth may be swallowed accidentally, especially if the victim is hysterical. If the victim is unconscious, this option is not possible. Milk has been shown to be an acceptable storage medium (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986) because, for short periods of time, milk is compatible with the cells of the tooth. There are several problems with using milk, however. Milk is not always available at an accident site. If milk is available, it can be sour or it can become sour (e.g., on a very hot day). Sour milk is a poor storage medium and can damage the cells of the tooth. The milk must be cold and fresh; powdered milk is damaging to the periodontal ligament (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986).
88
Patient Management
Exchange
% Success 90
80 70 60 50 40 30 20 10 0 0
30
W FIGURE
45
60
75 90 105 Time (minutes)
2 Replantation
success
The best storage media are pH-balanced, cellpreserving fluids such as Hank’s solution and Eagle’s medium (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986). These media are biocompatible with the tooth cells and can keep the cells viable for at least 12 hours and, sometimes, for several days. Hank’s solution does not need to be refrigerated and can be kept on the shelf for long periods of time. The pH-balanced, cell-preserving fluids contain ingredients such as glucose, calcium, and magnesium ions, which can sustain and reconstitute the depleted cellular components of the periodontal ligament cells (Blomlof, 1981b; Blomlof & Otteskog, 1980). These fluids can rejuvenate the degenerated periodontal ligament cells and permanent replantation occurs in more than 90% of avulsed teeth soaked in these fluids for 30 minutes (Matsson, Andreasen, Cvek, & Granath, 1982). Therefore any tooth that has been stored in a dry medium for a short period of time can be partially reconstituted by soaking it in one of these fluids for 30 minutes. These fluids have been used successfully as storage media by clinicians and researchers and are recommended for use (Andreasen, et al., 1978; Comfort, 1980; Viener, 1969). All storage media must be held in some kind of’ container. The container should be nondamaging, break-resistant, and spill-proof and should facilitate the removal of the tooth by the dentist. w TRANSPORTATION
MEDIA
OPTIONS
The manner in which the tooth is transported to the dentist’s office has significant effects on the success
rate
versus
N TABLE
transport
120
time
135
150
to repiantation
2 Characteristics
of an ideal
container
--.
s Break-resistant * Nontoxic l Easy to use n Soft inner walls l Tightly fitting top l Sterile 9 Protects tooth from damage during transport l Permits debris on tooth to be washed off n Facilitates easy, nondamaging removal of tooth * Air-tight and leak-proof
of replantation. The tooth should not be touched on its root portion; each time the root is touched, cells are crushed and will die. An ideal container for transporting the tooth prevents crushing of the periodontal ligament and allows the tooth to be removed atraumatically from the container. The transport container that is chosen should conform to these characteristics as closely as possible (Table 2). Cost for the treatment, which includes emergency treatment, root canal treatment, and final restoration will vary from dentist to dentist and from region to region but should be approximately $380.00. The cost for replacing a lost front tooth with fixed bridgework is approximately $1500.00 and may amount to $10,000 over the patlent’s life. Besides the aesthetic and psychologic advantages of retaining an avulsed
Journal of Pediatr ic Health Care
Patient
w FIGURE 3 Components
tooth, there are also significant tages . n
of the
Emergency
economic advan-
Preserving
Exchange
89
System.
ily remove the tooth from the container without damaging the tooth. Storing and transporting the tooth in such a system will safely preserve the tooth for up to 12 hours. 4. If a storage system like the Emergency Tooth Preservation System is not available, the avulsed tooth should be stored in fresh, whole refrigerated milk in a plastic container that has a tightly fitting top. 5. The patient and the tooth should be brought to a dentist as quickly as possible.
DISCUSSION
Despite all precautions, teeth will be accidentally avulsed. Extensive research has shown that nearly all avulsed teeth can be saved by replanting the avulsed tooth. By attempting to preserve the vitality of the periodontal ligament cells of the tooth, the health care provider can play an important role in preventing the loss of these avulsed teeth. The following clinical guidelines are recommended: 1. If the tooth is to be replanted immediately, it should be rinsed with a pH-balanced preserving solution or sterile saline solution. The tooth should be held in place by having the victim bite on gauze. The tooth should be held only by the enamel portion. 2. No attempt should be made to clean, sterilize, or scrape the tooth. 3. If the tooth is not to be replanted immediately, it should be stored in a biocompatible, secure storage environment such as an Emergency Tooth Preserving System (Biological Rescue Products, Inc., Pottstown, Pa.). The Emergency Tooth Preserving System is an ideal container for storage and transportation (Krasner, Rankow, Ehrenreich, 1989). It contains a sterile, pH-balanced preserving solution, is breakresistant, and has a screw-on top (Fig. 3). There is suspension netting in a removable basket inside the container. The netting holds the tooth securely suspended in the pH-balanced preserving fluid during transport, thus protecting and washing the tooth simultaneously. Handles on the basket allow the dentist to eas-
Tooth
Management
n
SUMMARY
More than 2 million teeth are accidentally avulsed each year in the United States. Most of the victims are children. Almost all of these teeth can be saved if the proper treatment is instituted. Regardless of the frequency with which it occurs, every pediatric health care provider must be prepared for patients who have avulsed teeth. By instituting the proper treatment, the provider may help to save a victim’s tooth, thus saving the family and child the expense of dental treatment and the possible psychologic problems associated with false teeth. Each health care provider should take the following steps: 1. Inform
all health care personnel
that avulsed teeth
can and should be saved. 2. Teach all health care personnel what action should be taken if a tooth is avulsed. 3. Fabricate or purchase tooth-preserving devices such as the Emergency Tooth Preserving System, which can safely store, preserve, and transport avulsed teeth.
4. Place these tooth-preserving devices at strategic locations such as in emergency kits or at nurses’ stations. w
REFERENCES American Dental Association. (1984). Accepted Dental Therapeutics. Chicago, IL: American Dental Association. Ad Hoc Committee on Treatment of the Avulsed Tooth. American Association of Endodontists. (1983). Recommended guidelines for the treatment of the avulsed tooth. Journal ofEndoabntics 9, 571. Andreasen, J. 0. (1970). Etiology and pathogenesis of traumatic dental injuries. Scandinavian Journal qf Dentai Research, 7X, 329-342. Andreasen, J. 0. (1975). Periodontal healing after replantatiorl of traumatically avulsed human teeth. Assessment by mobilit\ testing and radiography. Acta Odontolu@a Scandinavia, .?.?, 325-335. Andreasen, J. 0. (1980). A time-relarcd study of periodontal hcaling and tooth resorption activity afier rcplantation of mature permanent incisors in monkeys. Swedish Dental Journal, 4, 10 I110. Andreasen, J. 0. (1981a). Exarticulations. .Traumatic znjuvzes o/ the teeth. (2nd ed). (pp. 203-242). pcnhagen: Munkspaard Lrd. Andreasen, J. 0. (1981b). Relationship between ccl1 damage 111 the periodontal ligament after replantation and subsequrnr development of root resorption. A rime-related stud\r in man keys. Acta Oaimtolodia Scandinavia, .?9, 1 S-25. Andreasen, J. O., & Hjrting-Hansen, E. (1966a). Rcplantatiotl of teeth I. Radiographic and clinical study of 110 human tccrh replanted after accidental loss. Acta Oabntolo&a ScandinaGz, 24, 263-286. Andreasen, J. O., & Hjrting-Hansen, Ii. (1966b). Replantanon of teeth II. Histological study of replanted anterior teeth in humans. Acta Odontologia Scandinavia, 24, 287-306. Andreasen, J. O., & Kristerson, L. (1981a). Repair processes ln the cervical region of replanted and transplanted teeth in man keys. International Journal of Oral Suye~, IO. 128-136. Andreasen, J. 0.. & Kristerson. L. i 198 1 b I. The effect of limited drying or removal of the periodontal ligament. Periodontal healing after replantation of mature permanent incisors in monkeys. Acta Odontologia Scandinavia, 39, 1 13. Andreasen, J. O., Reinholdt, J., Riis, I., Dybdahl, R.. Sdcr. I:~
O., & Otteskog, I’. ( 1978). Periodontal and pulpal hcahng oi monkey incisors preserved in tissue culture before replanratiol> International Joumd of’ Oral Surgery. 7. 104-l 12. Blomlof, L. (1981a). Effect of storage media with ciiffcrux I
n
REPORl-S
Margaret Brady, PhD, RN, CPNP California State University, Long Beach Department of Nursing
n
Margaret Crey, Dr PH, RN, CPNP University of Pennsylvania School of Nursing Philadelphia, Pennsylvania
The Treatment of Avulsed Teeth f’aul
K. Kramer,
C
hildren are the group that most often experience a traumatic accidental injury called tooth avulsion. This problem affects 1 in every 200 school-aged children, and injury can occur at home, in school, or during play and sports activities. The consequences of this accident can be serious, and a child may suffer with them for the rest of his or her life. Nearly all avulsed teeth (there are over 2 million each year in the United States) can be saved by a procedure called replantation. This procedure is recommended by the American Dental Association (1984) and by the American Association of Endodontists (1983). For replantation to be successful, however, the manner in which the avulsed tooth is handled before replantation is crucial. This paper will discuss methods for handling avulsed teeth before replantation to prepare health care providers for an accident involving tooth avulsion. n RATIONALE FOR AVULSED TOOTH REPLANTATION
Dental research has shown that almost any tooth that has been avulsed can be replanted and will be retained permanently (Andreasen & Kristerson, 1981a; Blomlof, 1981b, 1981~; Seltzer & Krasner, 1988). When a tooth is avulsed from its socket, the periodontal ligament that joins the tooth to the bon! socket is ripped in half; half remains on the socket wall, and the other halfremains attached to the tooth (Fig. 1). The portion left in the socket remains viable with no additional treatment because it is bathed in the blood that fills the socket. The problem area is the portion of the ligament that remains on the tooth root. If this portion of the ligament remains viable Paul R. Krasner of Dentistry.
86
is Clinical
Associate
Professor,
Temple
Unwersity
School
n
LIDS
when the tooth is replanted, the ligament will reattach to the periodontal ligament fibers remaining in the socket and can be retained permanently. All treatment must therefore focus on maintaining the viability of the periodontal ligament that is still attached to the tooth (Andreasen, 1975, 1981 b; Cvek, Granath, & Hollender, 1975). The viability of the periodontal ligament can be enhanced by prcventing crushing of the cells of the ligament (Andreasen & Kristerson, 1981a; Hammarstrom, Pierce, Blomlof, Feiglin, & Lindskog, 1986) and by preventing dissolution of the normal cell composition and metabolism of these cells (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al.. 1986). Whatever treatment is used to save an avulsed tooth should attempt to create an environment that simulates as closely as possible the original tooth socket. The best way to create such an environment is by placing the tooth back into the socket immediately (Andreasen & Hjrting-Hansen, 1966a, 1966b; Andreasen & Kristerson, 1981b). If the tooth is rcplanted within 15 to 30 minutes of the accident, there is more than a 90% chance that the tooth will be retained permanently (Andreasen & HjrtingHansen, 1966a, 1966b). After 30 minutes, sufficient numbers of periodontal ligament cells on the root will die so that the possibility of successful ligament reattachment diminishes rapidly (Fig. 2). n
TREATMENT OF THE AVULSED TOOTH
If the avulsed tooth is not placed back into its socket immediately, there still may be a significant chance that the tooth can be retained successhlly after replantation (Andreasen, et al., 1978; Blomlof, 1981a, 198 1b). Whether replantation is successful depends almost totally on how the tooth is stored, preserved,
JOURNAL.
OF PtDlATKlC
HEALTH
CAR1
Journal of Pediatric Health
Patient Management
Care
Severed
k;;;‘J
Socket
Pulo 1
Exchange
87
of Avulsed Tooth
-
t
Normal Tooth
Tooth Being Avulsed n
n
TABLE n
. . . . .
1 Tooth preservation
FIGURE 1 Anatomy
media
Dry media (toilet tissue or gauze) Tap water Sterile saline solution Saliva Milk pH-balanced, cell-preserving fluids (Eagle’s medium or Hank’s solution)
and handled. The media chosen for storage and preservation should be compatible with the tooth root cells. The storage options are shown in Table 1. n
STORAGE MEDIA OPTIONS
The worst storage medium is a drying medium such as toilet tissue or gauze (Andreasen, 1975, 1980, 1981b; Andreasen & Kristerson, 1981b; Blomlof, 1981b). These types of media will dry out the periodontal ligament cells and cause immediate cell death. Allowing the tooth to air-dry or soaking the tooth in tap water is equally destructive. All of these methods of storage should be avoided. Sterile saline solution is also damaging to the tooth cells if the avulsed tooth is allowed to soak in the solution for more than 1 to 2 hours (Blomlof, 1981a, 1981b; Blomlof & Otteskog, 1980). Saline solution
Avulsed
Tooth3
of tooth avuision.
lacks the essential nutrients Mg’ +, Ca’ +, and glucose, which are necessary to replenish nutrients used by the normal metabolic process of the periodontal ligament cells (Blomlof, 1981b; Blomlof & Otteskog, 1980). Saliva can be used as a storage medium for short periods of time. Saliva can be damaging to the tooth cells, however, if avulsed teeth are soaked in it for more than 1 hour (Blomlof, 1981a, 1981b; Blomlof & Otteskog, 1980). Saliva also contaminates the tooth with bacteria (Hammarstrom, et al., 1986). The tooth can be placed under the tongue of the accident victim; however, there is a danger that the tooth may be swallowed accidentally, especially if the victim is hysterical. If the victim is unconscious, this option is not possible. Milk has been shown to be an acceptable storage medium (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986) because, for short periods of time, milk is compatible with the cells of the tooth. There are several problems with using milk, however. Milk is not always available at an accident site. If milk is available, it can be sour or it can become sour (e.g., on a very hot day). Sour milk is a poor storage medium and can damage the cells of the tooth. The milk must be cold and fresh; powdered milk is damaging to the periodontal ligament (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986).
88
Patient Management
Exchange
% Success 90
80 70 60 50 40 30 20 10 0 0
30
W FIGURE
45
60
75 90 105 Time (minutes)
2 Replantation
success
The best storage media are pH-balanced, cellpreserving fluids such as Hank’s solution and Eagle’s medium (Blomlof, 1981b; Blomlof & Otteskog, 1980; Hammarstrom, et al., 1986). These media are biocompatible with the tooth cells and can keep the cells viable for at least 12 hours and, sometimes, for several days. Hank’s solution does not need to be refrigerated and can be kept on the shelf for long periods of time. The pH-balanced, cell-preserving fluids contain ingredients such as glucose, calcium, and magnesium ions, which can sustain and reconstitute the depleted cellular components of the periodontal ligament cells (Blomlof, 1981b; Blomlof & Otteskog, 1980). These fluids can rejuvenate the degenerated periodontal ligament cells and permanent replantation occurs in more than 90% of avulsed teeth soaked in these fluids for 30 minutes (Matsson, Andreasen, Cvek, & Granath, 1982). Therefore any tooth that has been stored in a dry medium for a short period of time can be partially reconstituted by soaking it in one of these fluids for 30 minutes. These fluids have been used successfully as storage media by clinicians and researchers and are recommended for use (Andreasen, et al., 1978; Comfort, 1980; Viener, 1969). All storage media must be held in some kind of’ container. The container should be nondamaging, break-resistant, and spill-proof and should facilitate the removal of the tooth by the dentist. w TRANSPORTATION
MEDIA
OPTIONS
The manner in which the tooth is transported to the dentist’s office has significant effects on the success
rate
versus
N TABLE
transport
120
time
135
150
to repiantation
2 Characteristics
of an ideal
container
--.
s Break-resistant * Nontoxic l Easy to use n Soft inner walls l Tightly fitting top l Sterile 9 Protects tooth from damage during transport l Permits debris on tooth to be washed off n Facilitates easy, nondamaging removal of tooth * Air-tight and leak-proof
of replantation. The tooth should not be touched on its root portion; each time the root is touched, cells are crushed and will die. An ideal container for transporting the tooth prevents crushing of the periodontal ligament and allows the tooth to be removed atraumatically from the container. The transport container that is chosen should conform to these characteristics as closely as possible (Table 2). Cost for the treatment, which includes emergency treatment, root canal treatment, and final restoration will vary from dentist to dentist and from region to region but should be approximately $380.00. The cost for replacing a lost front tooth with fixed bridgework is approximately $1500.00 and may amount to $10,000 over the patlent’s life. Besides the aesthetic and psychologic advantages of retaining an avulsed
Journal of Pediatr ic Health Care
Patient
w FIGURE 3 Components
tooth, there are also significant tages . n
of the
Emergency
economic advan-
Preserving
Exchange
89
System.
ily remove the tooth from the container without damaging the tooth. Storing and transporting the tooth in such a system will safely preserve the tooth for up to 12 hours. 4. If a storage system like the Emergency Tooth Preservation System is not available, the avulsed tooth should be stored in fresh, whole refrigerated milk in a plastic container that has a tightly fitting top. 5. The patient and the tooth should be brought to a dentist as quickly as possible.
DISCUSSION
Despite all precautions, teeth will be accidentally avulsed. Extensive research has shown that nearly all avulsed teeth can be saved by replanting the avulsed tooth. By attempting to preserve the vitality of the periodontal ligament cells of the tooth, the health care provider can play an important role in preventing the loss of these avulsed teeth. The following clinical guidelines are recommended: 1. If the tooth is to be replanted immediately, it should be rinsed with a pH-balanced preserving solution or sterile saline solution. The tooth should be held in place by having the victim bite on gauze. The tooth should be held only by the enamel portion. 2. No attempt should be made to clean, sterilize, or scrape the tooth. 3. If the tooth is not to be replanted immediately, it should be stored in a biocompatible, secure storage environment such as an Emergency Tooth Preserving System (Biological Rescue Products, Inc., Pottstown, Pa.). The Emergency Tooth Preserving System is an ideal container for storage and transportation (Krasner, Rankow, Ehrenreich, 1989). It contains a sterile, pH-balanced preserving solution, is breakresistant, and has a screw-on top (Fig. 3). There is suspension netting in a removable basket inside the container. The netting holds the tooth securely suspended in the pH-balanced preserving fluid during transport, thus protecting and washing the tooth simultaneously. Handles on the basket allow the dentist to eas-
Tooth
Management
n
SUMMARY
More than 2 million teeth are accidentally avulsed each year in the United States. Most of the victims are children. Almost all of these teeth can be saved if the proper treatment is instituted. Regardless of the frequency with which it occurs, every pediatric health care provider must be prepared for patients who have avulsed teeth. By instituting the proper treatment, the provider may help to save a victim’s tooth, thus saving the family and child the expense of dental treatment and the possible psychologic problems associated with false teeth. Each health care provider should take the following steps: 1. Inform
all health care personnel
that avulsed teeth
can and should be saved. 2. Teach all health care personnel what action should be taken if a tooth is avulsed. 3. Fabricate or purchase tooth-preserving devices such as the Emergency Tooth Preserving System, which can safely store, preserve, and transport avulsed teeth.
4. Place these tooth-preserving devices at strategic locations such as in emergency kits or at nurses’ stations. w
REFERENCES American Dental Association. (1984). Accepted Dental Therapeutics. Chicago, IL: American Dental Association. Ad Hoc Committee on Treatment of the Avulsed Tooth. American Association of Endodontists. (1983). Recommended guidelines for the treatment of the avulsed tooth. Journal ofEndoabntics 9, 571. Andreasen, J. 0. (1970). Etiology and pathogenesis of traumatic dental injuries. Scandinavian Journal qf Dentai Research, 7X, 329-342. Andreasen, J. 0. (1975). Periodontal healing after replantatiorl of traumatically avulsed human teeth. Assessment by mobilit\ testing and radiography. Acta Odontolu@a Scandinavia, .?.?, 325-335. Andreasen, J. 0. (1980). A time-relarcd study of periodontal hcaling and tooth resorption activity afier rcplantation of mature permanent incisors in monkeys. Swedish Dental Journal, 4, 10 I110. Andreasen, J. 0. (1981a). Exarticulations. .Traumatic znjuvzes o/ the teeth. (2nd ed). (pp. 203-242). pcnhagen: Munkspaard Lrd. Andreasen, J. 0. (1981b). Relationship between ccl1 damage 111 the periodontal ligament after replantation and subsequrnr development of root resorption. A rime-related stud\r in man keys. Acta Oaimtolodia Scandinavia, .?9, 1 S-25. Andreasen, J. O., & Hjrting-Hansen, E. (1966a). Rcplantatiotl of teeth I. Radiographic and clinical study of 110 human tccrh replanted after accidental loss. Acta Oabntolo&a ScandinaGz, 24, 263-286. Andreasen, J. O., & Hjrting-Hansen, Ii. (1966b). Replantanon of teeth II. Histological study of replanted anterior teeth in humans. Acta Odontologia Scandinavia, 24, 287-306. Andreasen, J. O., & Kristerson, L. (1981a). Repair processes ln the cervical region of replanted and transplanted teeth in man keys. International Journal of Oral Suye~, IO. 128-136. Andreasen, J. 0.. & Kristerson. L. i 198 1 b I. The effect of limited drying or removal of the periodontal ligament. Periodontal healing after replantation of mature permanent incisors in monkeys. Acta Odontologia Scandinavia, 39, 1 13. Andreasen, J. O., Reinholdt, J., Riis, I., Dybdahl, R.. Sdcr. I:~
O., & Otteskog, I’. ( 1978). Periodontal and pulpal hcahng oi monkey incisors preserved in tissue culture before replanratiol> International Joumd of’ Oral Surgery. 7. 104-l 12. Blomlof, L. (1981a). Effect of storage media with ciiffcrux I
