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Using endodontic stabilizers for overdenture abutment teeth
Using endodontic abutment teeth C. Wayne Caswell,
D.D.S., MS.,*
stabilizers
for overdenture
and E. Steve Senia, D.D.S., M.S.**
University of Mississippi, Schoolof Dentistry, Jackson, Miss., and University of Texas Dental School, San Antonio, Tex.
T
he overdenture is an accepted alternative to the removal of teeth and the placement of complete dentures.‘,2 Retaining teeth for overdentures preserves alveolar bone and may provide proprioception by means of sensory input from the periodontal ligament.3,4 It contributes to increased support and stability for the prosthesis. Additional retention can be gained by using an attachment in the retained teeth.5 In overdenture construction the clinical crown is reduced; this improves the crown-to-root ratio and decreases the mobility of the tooth.6 However, many potential overdenture abutment teeth have short or conical roots or compromised bone support. Even though reduced considerably, these teeth may not be suitable for overdenture abutments. The use of an endodontic stabilizer can be of benefit because it improves the crown-to-root ratio by changing the fulcrum line so that it lies within bone. This decreases mobility and stabilizes the tooth.7-9
BACKGROUND
AND HISTORY
Endodontic implants were developed by Strock and Strock” in 1943. An extensive study was published in 1960 by Orlay. ” Frank’ described a more precise technique in 1967. Weine12 suggests the term endodontic stabilizer because the main function of the implant is to stabilize the periodontally involved tooth. The endodontic stabilizer should be differentiated from other prosthodontic endosteal implants (ramus frame, blade, staple, and so forth) because it is totally embedded within bone and has the distinct advantage of not communicating with the oral cavity.‘p9 The endodontic stabilizer is a biocompatible metal or singlecrystal sapphire rod that extends beyond the apex into bone and supplements the existing periodontal support. The metal is either a chrome-cobalt alloy (Vitallium, Union Broach Corp., Long Island City, N.Y.) or *AssistantProfessor, **Associate
530
Professor,
Department of Restorative Dentistry. Director of Graduate Endodontics.
titanium (Oratronics, New York, N.Y.). The singlecrystal sapphire stabilizer (Kyocera International, Inc., San Diego, Calif.) is chemically and structurally identical to single-crystal aluminum oxide. Bernier and Canby13 in a histologic study showed that chrome-cobalt alloys were well tolerated by tissue and bone. However, the research of Seltzer et a1.,14 which used an electron microscope, revealed corrosion products around the chrome-cobalt endodontic stabilizer. With the use of the electron microscope, Morris et a1.15showed minimum amounts of corrosion around titanium endodontic stabilizers in the form of titanium oxide. In a recent animal study with the single-crystal sapphire endosteal dental implant, McKinney and Koth16 demonstrated excellent clinical and histologic results. Smooth and threaded stabilizers are available. Judy et al.” reported that the threaded stabilizer was more retentive and formed a tighter apical seal. In 1977 Cranin et a1.18reported a statistical evaluation of 952 endosteal implants in humans. They found the endodontic stabilizer to be the most successful with a 91% successrate for 5 years. In this study all forms and types of stabilizers were considered in one group. Frank’ initially outlined the indications and contraindications for endodontic stabilizers. Endodontic stabilizers are indicated for overdenture abutment teeth (1) with extremely short roots (natural or from apicoectomy), (2) with conical roots, (3) with minimum bone support and excessive mobility, and (4) when an overdenture is indicated and no other tooth is suitable as an abutment. Endodontic stabilizers are contraindicated for overdenture abutment teeth (1) when a periodontal pocket communicates with the apex of the involved abutment tooth; (2) when anatomic structures such as the mandibular canal, mental foramen, maxillary sinus, and nares are in proximity to the apex; (3) when less than 2 mm of bone remains at the apex”; (4) when tooth
OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
Fig. 1. Endodontic stabilizer that has failed because of
Fig. 4. Reduction of incisal portion of tooth prior to
a periodontal
canal preparation.
communication.
Fig. 2. Endodon.tically
stabilized overdenture ment tooth that had a free gingival graft.
abut-
Fig. 3. Rubber dam used in placement of stabilizer.
inclination is such that the stabilizer will perforate soft tissues; and (5) when the patient has a history of bleeding problems, a debilitating systemic condition, or a history of radiation therapy in the region of the tooth.
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 5. Removal of 1 mm of stabilizer to ensure apical seal.
cement on r:Aainder
PERIODONTAL
of stabilizer within 60th.’
CONSIDERATIONS
The principal cause of failure in the endodontic stabilizer is a periodontal communication to the apex of the root (Fig. 1).20 When soft tissue defects exist, a gingivectomy is indicated to remove the minor pocket-
531
CASWELL
AND
SENlA
Fig. 7. Mandibular canines that are to be treated with endodontic stabilizer. A, Clinical appearance prior to treatment. B, Pretreatment radiograph. C, Radiograph after cementation of endodontic stabilizer. ing. Osseous recontouring will be necessary for severe bony defects. An adequate band of attached gingiva is essential to maintain adequate health of the abutment tissue. Ramfjord*’ demonstrated that less than 1 mm of attached gingiva could not be kept free of gingival inflammation despite good oral hygiene, while attached gingiva with a width of 1 mm or more could be kept free of clinical inflammation. This criterion for attached gingiva must be applied to overdenture abutment teeth. If inadequate attached gingiva is present, a free gingival graft from the palate or an edentulous ridge must be done (Fig. 2).** Periodontal health should be established and good oral hygiene maintained before an endodontic stabilizer can be considered.
532
ENDODONTIC
CONSIDERATIONS
There are a number of similar techniques for the placement of endodontic stabilizers in the dental literature.7p9*‘2*19Treatment of a tooth with a vital pulp can be completed in one appointment, whereas, treatment of a tooth with a necrotic pulp may be done in two visits. Accepted endodontic procedures and concepts are followed when the canal is cleaned and shaped. Because strict asepsis is necessary, the rubber dam is always used to maintain a saliva-free environment (Fig. 3). Endodontic stabilizers do not bend and need a straight path for insertion. Because the crown is to be removed for the overdenture, access can be made quickly and easily by cutting off the incisal third or half of the crown prior to canal preparation (Fig. 4). The
OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
Fig. 8. A and B. Mandibular incisor displaced distolabially by trauma. A, Clinical view of tooth to be used as an abutment for a removable partial overdenture. B, Pretreatment radiograph.
Fig.. 8. C and D. C, Radiograph after cementation of endodontic stabilizer. D, Clinical intraoral view of patient after insertion of prosthesis. reduction of the crown should be coordinated between the endodontist and the prosthodontist to ensure proper and accurate reduction of the tooth. The stabilizer slhould extend at least 7 mm into bone to obtain stability. However, penetration of soft tissue or injury to anatomic structures must be avoided. If a mobile tooth was splinted prior to treatment, it should
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
be maintained during the treatment phase to allroid accidental avulsion of the tooth. The stabilizer shemid be deep enough in the bone to eliminate or reduce the mobility of the tooth to a Class I mobility. The endodontic stabilizer must bind tightly in the tooth and seal the apex. The lack of an apical seal is the most frequent cause of endodontic failure.12 To emiure
533
CASWELL
AND
SENIA
Fig. 9. A and B. Mandibular incisor that had a poor prognosis as an overdenture abutment tooth. A, Clinical view of tooth prior to treatment. Note lack of attached gingiva. B, Poor crown-to-root ratio prior to treatment.
Fig. 9. C and D. C, Improved crown-to-root ratio after insertion of stabilizer. Amalgam is coronal to stabilizer and can be used as final restoration. D, External attachment improved retention of overdenture. A free gingival graft increased attached gingiva. an adequate seal, the apical portion of the stabilizer is reduced 1 mm prior ;o cementation (Fig. 5). This avoids bone contact at the tip of the stabilizer and ensures apical binding. The stabilizer is cemented in place with a root canal sealer (apical 3 mm of tooth) and zinc phosphate cement on the remainder of the stabilizer within the tooth (Fig. 6). 534
PROSTHODONTIC
CONSIDERATIONS
The endodontic stabilizer converts a weak or questionable tooth into one that can serve as a functional overdenture abutment tooth (Figs. 7 to 9). Sound prosthodontic principles should be observed to ensure success. Vertical and horizontal forces should not be placed on the tooth for 3 weeks. If the patient is OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
currently wearing an overdenture, it should be relieved around the abutment tooth to ensure that the overdenture is supported by soft tissue. This area of relief can be relined at a subsequent appointment. If mobility is present after 3 weeks, additional time should be allowed before forces are placed on the tooth. When natural dentition or a prosthesis is present in the opposing arch and the patient is not wearing an overdenture to protect the abutment tooth, care must be taken to avoid traumatic occlusion during chewing or sleep. A provisional prosthesis may be necessary for this purpose. The overdenture occlusion should not have lateral interferences to avoid detrimental forces on the endodontically stabilized abutment tooth. Further, the overdenture should not impinge on the gingival tissue around the tooth. This area should be carefully relieved to avoid irritation of the tissue. Final coverage of the stabilized tooth should be a well-polished amalgam or a metal coping. If a post or internal attachment is to be used, proper planning and care must be taken to allow sufficient space within the canal. If possible, 1 to 2 mm of zinc phosphate cement or gutta-percha should be placed between the stabilizer and the post or attachment. If contact is made with the stabilizer during post preparation, the apical seal may be broken :and failure will occur.23
5 6 7 8
9
10
11 12 13
14
15
16
17
CONCLUSION The use of the endodontic stabilizer is not a panacea. With proper treatment planning and patient selection, it does offer a method of retention and stabilization for teeth that otherwise have a poor prognosis. Strict attention must be given to the principles of periodontics, endodontics, and prosthodontics.
18.
19. 20. 21.
REFERENCES 1. 2.
3.
4.
THE
Miller,
I’. A.: Complete dentures supported by natural teeth. J PROSTHET DEN.~ 8:924, 1958. Morrow, R. M., Feldmann, E. E., Rudd, K. D., and Trovillion, H. M.: Tooth-supported complete dentures: An approach to preventive prosthodontics. J PROSTHET DENT 21:513, 1969. Crum, R. J., and Rooney, G. E.: Alveolar bone loss in overdentures: A five-year study. J PROSTHET DENT 40:610, 1978. Brewer, .4. A., and Morrow, R. M.: Overdentures, ed 2. St. Louis, 1980, The C. V. Mosby Co., p 5.
JOURNAL
OF PROSTHETIC
DENTISTRY
22.
23.
Preiskel, H. W.: Precision Attachments in Dentistry, ed 3. St. Louis, 1979, The C. V. Mosby Co., p 164. Dolder, E. J.: The bar joint mandibular denture. J PROSTHET DENT 11:689, 1961. Frank, A. L.: Improvement of the crown-root ratio by endodontic endosseous implants. J Am Dent Assoc 74:451, 1967. Silverbrand, H., Rabkin, M., and Cranin, A. N.: The uses of endodontic implant stabilizers in posttraumatic and periodontal disease. Oral Surg 45:920, 1978. Scopp, I. W., Dictow, R. L., and Lichtenstein, B. S.: Endodontic endosseous implants: A conservative method for stabilization in geriatric patients. J Periodontol 40~48, 1961. Strock, A. E., and Strock, M. S.: Method of reinforcing pulpless anterior teeth: Preliminary report. J Oral Surg 1:252, 1943. Orlay, H. G.: Endodontic splinting treatment in periodontal disease. Br Dent J 108:118, 1960. Weine. F. S.: Endodontic Therapy, ed 3. St. Louis, 1982, The C. V. Mosby Co., p 521. Bernier, J. L., and Canby, C. P.: Histologic studies on the reaction of alveolar bone to vitallium implants. J Am Dent Assoc 30:188, 1943. Seltzer, S., Green, D. B., de la Guardia, R., Maggio, J., and Barnett, A.: Vitallium endodontic implants: A scanning electron microscope, electron probe, and histologic study. Oral Surg 35:828, 1973. Morris, D. R., Barnett, A. M., and Maggio, J. D.: A scanning electron microscope examination of endodontic implants. Oral Implant01 3:139, 1972. McKinney, R. V., and Koth, D. L.: The single-crystal sapphire endosteal dental implant: Material characteristics and 18month experimental animal trials. J PROSTHET DENT 47:69, 1982. Judy, K., Eilberg, R., Lew, I., and Green, D.: Cement leakage and retention of threaded and nonthreaded endodontic implants. Oral Implant01 328, 1972. Cranin, A. N., Rabkin, M. F., and Garfinkel, L.: A statistical evaluation of 952 endosteal implants in humans. J Am Dent Assoc 94:315, 1977. Morse, D. R.: Endodontic implants: A review and new approach. NY State Dent J 35:5, 1969. Perel, M. L.: Dental Implantology and Prosthesis. Philadelphia, 1977, J. B. Lippincott Co., p 184. Ramfjord, S. P.: Periodontal aspects of restorative dentistry. J Oral Rehabil 1:107, 1974. Sullivan, H. C., and Atkins, J. H.: Free autogenous gingival grafts. I. Principles of successful grafting. Periodontics 6~121, 1968. Cranin, A. N.: Oral Implantology. Springfield, III., 1970, Charles C Thomas, Publisher, p 237.
Reprint reyuest.r to: DR. C. WAVHE CASWELL UNIVERSITY OF MISSISSIPPI, SCHOOL OF DENTISTRY DEPARTMENT
OF RESTORATIVE
DENTISTRY
2500 NORTHSTATE ST. JACKSON,MS 39216
535
D.D.S., MS.,*
stabilizers
for overdenture
and E. Steve Senia, D.D.S., M.S.**
University of Mississippi, Schoolof Dentistry, Jackson, Miss., and University of Texas Dental School, San Antonio, Tex.
T
he overdenture is an accepted alternative to the removal of teeth and the placement of complete dentures.‘,2 Retaining teeth for overdentures preserves alveolar bone and may provide proprioception by means of sensory input from the periodontal ligament.3,4 It contributes to increased support and stability for the prosthesis. Additional retention can be gained by using an attachment in the retained teeth.5 In overdenture construction the clinical crown is reduced; this improves the crown-to-root ratio and decreases the mobility of the tooth.6 However, many potential overdenture abutment teeth have short or conical roots or compromised bone support. Even though reduced considerably, these teeth may not be suitable for overdenture abutments. The use of an endodontic stabilizer can be of benefit because it improves the crown-to-root ratio by changing the fulcrum line so that it lies within bone. This decreases mobility and stabilizes the tooth.7-9
BACKGROUND
AND HISTORY
Endodontic implants were developed by Strock and Strock” in 1943. An extensive study was published in 1960 by Orlay. ” Frank’ described a more precise technique in 1967. Weine12 suggests the term endodontic stabilizer because the main function of the implant is to stabilize the periodontally involved tooth. The endodontic stabilizer should be differentiated from other prosthodontic endosteal implants (ramus frame, blade, staple, and so forth) because it is totally embedded within bone and has the distinct advantage of not communicating with the oral cavity.‘p9 The endodontic stabilizer is a biocompatible metal or singlecrystal sapphire rod that extends beyond the apex into bone and supplements the existing periodontal support. The metal is either a chrome-cobalt alloy (Vitallium, Union Broach Corp., Long Island City, N.Y.) or *AssistantProfessor, **Associate
530
Professor,
Department of Restorative Dentistry. Director of Graduate Endodontics.
titanium (Oratronics, New York, N.Y.). The singlecrystal sapphire stabilizer (Kyocera International, Inc., San Diego, Calif.) is chemically and structurally identical to single-crystal aluminum oxide. Bernier and Canby13 in a histologic study showed that chrome-cobalt alloys were well tolerated by tissue and bone. However, the research of Seltzer et a1.,14 which used an electron microscope, revealed corrosion products around the chrome-cobalt endodontic stabilizer. With the use of the electron microscope, Morris et a1.15showed minimum amounts of corrosion around titanium endodontic stabilizers in the form of titanium oxide. In a recent animal study with the single-crystal sapphire endosteal dental implant, McKinney and Koth16 demonstrated excellent clinical and histologic results. Smooth and threaded stabilizers are available. Judy et al.” reported that the threaded stabilizer was more retentive and formed a tighter apical seal. In 1977 Cranin et a1.18reported a statistical evaluation of 952 endosteal implants in humans. They found the endodontic stabilizer to be the most successful with a 91% successrate for 5 years. In this study all forms and types of stabilizers were considered in one group. Frank’ initially outlined the indications and contraindications for endodontic stabilizers. Endodontic stabilizers are indicated for overdenture abutment teeth (1) with extremely short roots (natural or from apicoectomy), (2) with conical roots, (3) with minimum bone support and excessive mobility, and (4) when an overdenture is indicated and no other tooth is suitable as an abutment. Endodontic stabilizers are contraindicated for overdenture abutment teeth (1) when a periodontal pocket communicates with the apex of the involved abutment tooth; (2) when anatomic structures such as the mandibular canal, mental foramen, maxillary sinus, and nares are in proximity to the apex; (3) when less than 2 mm of bone remains at the apex”; (4) when tooth
OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
Fig. 1. Endodontic stabilizer that has failed because of
Fig. 4. Reduction of incisal portion of tooth prior to
a periodontal
canal preparation.
communication.
Fig. 2. Endodon.tically
stabilized overdenture ment tooth that had a free gingival graft.
abut-
Fig. 3. Rubber dam used in placement of stabilizer.
inclination is such that the stabilizer will perforate soft tissues; and (5) when the patient has a history of bleeding problems, a debilitating systemic condition, or a history of radiation therapy in the region of the tooth.
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 5. Removal of 1 mm of stabilizer to ensure apical seal.
cement on r:Aainder
PERIODONTAL
of stabilizer within 60th.’
CONSIDERATIONS
The principal cause of failure in the endodontic stabilizer is a periodontal communication to the apex of the root (Fig. 1).20 When soft tissue defects exist, a gingivectomy is indicated to remove the minor pocket-
531
CASWELL
AND
SENlA
Fig. 7. Mandibular canines that are to be treated with endodontic stabilizer. A, Clinical appearance prior to treatment. B, Pretreatment radiograph. C, Radiograph after cementation of endodontic stabilizer. ing. Osseous recontouring will be necessary for severe bony defects. An adequate band of attached gingiva is essential to maintain adequate health of the abutment tissue. Ramfjord*’ demonstrated that less than 1 mm of attached gingiva could not be kept free of gingival inflammation despite good oral hygiene, while attached gingiva with a width of 1 mm or more could be kept free of clinical inflammation. This criterion for attached gingiva must be applied to overdenture abutment teeth. If inadequate attached gingiva is present, a free gingival graft from the palate or an edentulous ridge must be done (Fig. 2).** Periodontal health should be established and good oral hygiene maintained before an endodontic stabilizer can be considered.
532
ENDODONTIC
CONSIDERATIONS
There are a number of similar techniques for the placement of endodontic stabilizers in the dental literature.7p9*‘2*19Treatment of a tooth with a vital pulp can be completed in one appointment, whereas, treatment of a tooth with a necrotic pulp may be done in two visits. Accepted endodontic procedures and concepts are followed when the canal is cleaned and shaped. Because strict asepsis is necessary, the rubber dam is always used to maintain a saliva-free environment (Fig. 3). Endodontic stabilizers do not bend and need a straight path for insertion. Because the crown is to be removed for the overdenture, access can be made quickly and easily by cutting off the incisal third or half of the crown prior to canal preparation (Fig. 4). The
OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
Fig. 8. A and B. Mandibular incisor displaced distolabially by trauma. A, Clinical view of tooth to be used as an abutment for a removable partial overdenture. B, Pretreatment radiograph.
Fig.. 8. C and D. C, Radiograph after cementation of endodontic stabilizer. D, Clinical intraoral view of patient after insertion of prosthesis. reduction of the crown should be coordinated between the endodontist and the prosthodontist to ensure proper and accurate reduction of the tooth. The stabilizer slhould extend at least 7 mm into bone to obtain stability. However, penetration of soft tissue or injury to anatomic structures must be avoided. If a mobile tooth was splinted prior to treatment, it should
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
be maintained during the treatment phase to allroid accidental avulsion of the tooth. The stabilizer shemid be deep enough in the bone to eliminate or reduce the mobility of the tooth to a Class I mobility. The endodontic stabilizer must bind tightly in the tooth and seal the apex. The lack of an apical seal is the most frequent cause of endodontic failure.12 To emiure
533
CASWELL
AND
SENIA
Fig. 9. A and B. Mandibular incisor that had a poor prognosis as an overdenture abutment tooth. A, Clinical view of tooth prior to treatment. Note lack of attached gingiva. B, Poor crown-to-root ratio prior to treatment.
Fig. 9. C and D. C, Improved crown-to-root ratio after insertion of stabilizer. Amalgam is coronal to stabilizer and can be used as final restoration. D, External attachment improved retention of overdenture. A free gingival graft increased attached gingiva. an adequate seal, the apical portion of the stabilizer is reduced 1 mm prior ;o cementation (Fig. 5). This avoids bone contact at the tip of the stabilizer and ensures apical binding. The stabilizer is cemented in place with a root canal sealer (apical 3 mm of tooth) and zinc phosphate cement on the remainder of the stabilizer within the tooth (Fig. 6). 534
PROSTHODONTIC
CONSIDERATIONS
The endodontic stabilizer converts a weak or questionable tooth into one that can serve as a functional overdenture abutment tooth (Figs. 7 to 9). Sound prosthodontic principles should be observed to ensure success. Vertical and horizontal forces should not be placed on the tooth for 3 weeks. If the patient is OCTOBER
1983
VOLUME
50
NUMBER
4
ENDODONTIC
STABILIZERS
currently wearing an overdenture, it should be relieved around the abutment tooth to ensure that the overdenture is supported by soft tissue. This area of relief can be relined at a subsequent appointment. If mobility is present after 3 weeks, additional time should be allowed before forces are placed on the tooth. When natural dentition or a prosthesis is present in the opposing arch and the patient is not wearing an overdenture to protect the abutment tooth, care must be taken to avoid traumatic occlusion during chewing or sleep. A provisional prosthesis may be necessary for this purpose. The overdenture occlusion should not have lateral interferences to avoid detrimental forces on the endodontically stabilized abutment tooth. Further, the overdenture should not impinge on the gingival tissue around the tooth. This area should be carefully relieved to avoid irritation of the tissue. Final coverage of the stabilized tooth should be a well-polished amalgam or a metal coping. If a post or internal attachment is to be used, proper planning and care must be taken to allow sufficient space within the canal. If possible, 1 to 2 mm of zinc phosphate cement or gutta-percha should be placed between the stabilizer and the post or attachment. If contact is made with the stabilizer during post preparation, the apical seal may be broken :and failure will occur.23
5 6 7 8
9
10
11 12 13
14
15
16
17
CONCLUSION The use of the endodontic stabilizer is not a panacea. With proper treatment planning and patient selection, it does offer a method of retention and stabilization for teeth that otherwise have a poor prognosis. Strict attention must be given to the principles of periodontics, endodontics, and prosthodontics.
18.
19. 20. 21.
REFERENCES 1. 2.
3.
4.
THE
Miller,
I’. A.: Complete dentures supported by natural teeth. J PROSTHET DEN.~ 8:924, 1958. Morrow, R. M., Feldmann, E. E., Rudd, K. D., and Trovillion, H. M.: Tooth-supported complete dentures: An approach to preventive prosthodontics. J PROSTHET DENT 21:513, 1969. Crum, R. J., and Rooney, G. E.: Alveolar bone loss in overdentures: A five-year study. J PROSTHET DENT 40:610, 1978. Brewer, .4. A., and Morrow, R. M.: Overdentures, ed 2. St. Louis, 1980, The C. V. Mosby Co., p 5.
JOURNAL
OF PROSTHETIC
DENTISTRY
22.
23.
Preiskel, H. W.: Precision Attachments in Dentistry, ed 3. St. Louis, 1979, The C. V. Mosby Co., p 164. Dolder, E. J.: The bar joint mandibular denture. J PROSTHET DENT 11:689, 1961. Frank, A. L.: Improvement of the crown-root ratio by endodontic endosseous implants. J Am Dent Assoc 74:451, 1967. Silverbrand, H., Rabkin, M., and Cranin, A. N.: The uses of endodontic implant stabilizers in posttraumatic and periodontal disease. Oral Surg 45:920, 1978. Scopp, I. W., Dictow, R. L., and Lichtenstein, B. S.: Endodontic endosseous implants: A conservative method for stabilization in geriatric patients. J Periodontol 40~48, 1961. Strock, A. E., and Strock, M. S.: Method of reinforcing pulpless anterior teeth: Preliminary report. J Oral Surg 1:252, 1943. Orlay, H. G.: Endodontic splinting treatment in periodontal disease. Br Dent J 108:118, 1960. Weine. F. S.: Endodontic Therapy, ed 3. St. Louis, 1982, The C. V. Mosby Co., p 521. Bernier, J. L., and Canby, C. P.: Histologic studies on the reaction of alveolar bone to vitallium implants. J Am Dent Assoc 30:188, 1943. Seltzer, S., Green, D. B., de la Guardia, R., Maggio, J., and Barnett, A.: Vitallium endodontic implants: A scanning electron microscope, electron probe, and histologic study. Oral Surg 35:828, 1973. Morris, D. R., Barnett, A. M., and Maggio, J. D.: A scanning electron microscope examination of endodontic implants. Oral Implant01 3:139, 1972. McKinney, R. V., and Koth, D. L.: The single-crystal sapphire endosteal dental implant: Material characteristics and 18month experimental animal trials. J PROSTHET DENT 47:69, 1982. Judy, K., Eilberg, R., Lew, I., and Green, D.: Cement leakage and retention of threaded and nonthreaded endodontic implants. Oral Implant01 328, 1972. Cranin, A. N., Rabkin, M. F., and Garfinkel, L.: A statistical evaluation of 952 endosteal implants in humans. J Am Dent Assoc 94:315, 1977. Morse, D. R.: Endodontic implants: A review and new approach. NY State Dent J 35:5, 1969. Perel, M. L.: Dental Implantology and Prosthesis. Philadelphia, 1977, J. B. Lippincott Co., p 184. Ramfjord, S. P.: Periodontal aspects of restorative dentistry. J Oral Rehabil 1:107, 1974. Sullivan, H. C., and Atkins, J. H.: Free autogenous gingival grafts. I. Principles of successful grafting. Periodontics 6~121, 1968. Cranin, A. N.: Oral Implantology. Springfield, III., 1970, Charles C Thomas, Publisher, p 237.
Reprint reyuest.r to: DR. C. WAVHE CASWELL UNIVERSITY OF MISSISSIPPI, SCHOOL OF DENTISTRY DEPARTMENT
OF RESTORATIVE
DENTISTRY
2500 NORTHSTATE ST. JACKSON,MS 39216
535