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Treatment of intra-alveolar root fractures by cobalt-chromium implants
T R E A T M E N T OF I N T R A - A L V E O L A R R O O T F R A C T U R E S BY C O B A L T - C H R O M I U M I M P L A N T S * J. O. ANDREASEN
University Hospital, Copenhagen and Royal Dental College, Copenhagen IN a study of the events of healing in 48 cases of intra-alveolar root fractures, it was found that inflammatory changes occurred in the fracture line in 47 per cent. of the cases (Andreasen and Hjorting-Hansen, z967). A histological examination demonstrated that the origin of the inflammation was a pulpal necrosis in the coronal fragment. Most authors advocate extraction of teeth with root fracture when pulpal complications occur, but in recent years root canal treatment in such cases has been carried out with good results (Lindahl, I958; Michanowics, z963). If the fracture is located in the coronal third of the root an excessive loosening of the coronal fragment occurs. Intraradicular splinting, using a metal pin as a root canal filling to unite the two fragments, has been used as a method of stabilising the tooth (Grazide et aL, z956; Stacy, I965; Brugirard and Achard, z966). Another method has been to remove the apical fragment and replace it with a metallic implant retained in the coronal fragment (Brugirard and Achard, r966; Hansen, I966; Frank, z967). A similar implant technique has been used to stabilise teeth loosened by periodontal disease or root resection (Bruno, x954; Souza, z954; Parker, z956; Staegemann, 1957, I96O; Orlay, 196o; Ferrier, 196o; Shaykin, 1964; Hermann, I965; Frank, 1967). The purpose of the present study has been to evaluate the implant technique in cases of intra-alveolar root fractures which demonstrate pulpal complications and excessive loosening of the coronal fragment. MATERIAL AND METHODS The material consists of IO patients who had 12 intra-alveolar root fractures treated with cobalt-chromium implants. All the teeth were excessively loose, the fracture was located in the marginal third of the root, and a pulpal necrosis was present in all cases. The cobalt-chromium implants were constructed in the following way: An extracted central incisor was chosen as a phantom model and twothirds of the root was resected. A slightly tapered diamond bur (D. & Z. No. Ir8) was inserted in the root canal via a coronal access, and the bur forced through the canal to the level of the resected apex. A soft steel wire with a diameter of I'2 ram. was slightly bent and covered with softened wax. An impression was taken of the artificial root canal with the metal wire placed in the root canal in such a way that the curvature of the wire followed a palatal direction. After investment, a casting was performed in cobalt-chromium (Remanit ®). Due to the tapering of the casting a good marginal seal was created between the implant and the root surface (Fig. I, a, B, C and D). * Aided by a grant from the Danish Dental Association: 'Fonden til Stotte for Videnskabelige og Praktiske Undersogelser indenfor Tandlmgekunsten'. I4I
I42
BRITISH JOURNAL OF ORAL SURGERY
FIG. I A, From left to right: Phantom tooth model, diamond bur (D. & Z. No. xIS), soft steel wire covered with impression wax, and finished casting in cobalt-chromium. B, Cast implant inserted in phantom model, lateral view, note that the curvature of the implant follows a palatal direction. C, Frontal view. D, Note the close adaption between implant and root surface.
TREATMENT
OF
INTRA-ALVEOLAR
ROOT
143
FRACTURES
T h e following surgical p r o c e d u r e was performed. A mucoperiosteal flap was raised, a n d the apical f r a g m e n t was r e m o v e d (Fig. 2, A). T h e entire r o o t canal in the coronal f r a g m e n t was enlarged to the level o f t h e fracture line with t h e
A
B C FIG. 2 Case No. 5. A, Right upper central incisor with intra-alveolar root fracture demonstrating periapical inflammation. A mucoperiosteal flap has been raised and the apical fragment has been removed. B, Insertion of the implant. C, Radiograph immediately after insertion of the implant. TABLE
I
R E S U L T S A F T E R V I T A L L I U M I M P L A N T S IN 12 T E E T H INTRA-ALVEOLAR ROOT FRACTURES Case
number
I I 2
3 4 5 6 6 7 8
9 IO
* Tooth number z+ +z +3 -J-I
Observation period years 3 3 3 I½
I+
3 3 3
+I
Radiographic examination Periradicular radiolucency
Loosening
Fistula
_
m
+ +
-
+
+
-
+
+
m
2
+I
I+ Z+ I+ +I
Clinical examination
WITH
2
A I
3
* The figures indicate the region according to Haderup's notation: - denotes the lower jaw, + the upper jaw. If the sign is placed to the right of the figure (I + , for example), the right side is indicated, and vice versa (Haderup, I887).
BRITISH
144
JOURNAL
OF ORAL S U R G E R Y
A
B C FIG. 3 Case No. 8. A, Pre-operative conditions of intra-alveolar root fracture of both central incisors. + I demonstrates periradicular radiolucency due to inflammatory changes in the fracture line. B, Radiograph immediately after insertion of the implant in + i. C, Radiograph 31 years after operation. Note the osseous healing with a narrow radiolucent line around the implant.
A
B C FIG. 4 Case No. 4. A, Condition after insertion of implant.
B, Post-operative condition after x} years. Note radiolucent area around the fractured root surface. C, Collagenous tissue from case No. 4 covering the most apical part of the implant.
TREATMENT OF INTRA-ALVEOLAR ROOT FRACTURES
145
tapered diamond bur. A cobalt-chromium implant was inserted in the root canal and the direction of the implant was noted; a cavity was created in the alveolar bone which assured that the length of the implant exceeded the original length of the root by 2 to 6 ram. The length of the implant was adjusted to the cavity in the bone (Fig. 2, B), and in addition the length of the implant was adjusted to the level of the lingual surface of the crown. The implant was cemented in the root canal with an ordinary zinc-phosphate cement and special care was taken to remove all excess cement (Fig. 2, c). RESULTS In Table I the results of treatment of I2 teeth are shown. It is noted that the results have been favourable in 8 cases with an observation period from I to 3½ years. Clinically in these cases the teeth were firm and with a normal pochet depth. Radiographically a narrow radiolucent area was seen around the implant suggesting the presence of a layer of connective tissue (Fig. 3)- In four cases a periapical radiolucency and in two cases the presence of a fistula indicated inflammatory changes. At re-operation a leak between the post and the root canal was found. A biopsy was taken of the tissue covering the apical part of the post in one of these cases. Histological examination revealed connective tissue without inflammatory changes (Fig. 4). DISCUSSION The purpose of the operation has been to place the fulcrum of the transversal movements in a more apical position in teeth with root fractures. The clinical examination showed that this could be achieved with the implant technique. In four cases (33 per cent.) inflammatory changes were found; approximately the same failure rate as reported by Strindberg (I956), who found 35 per cent. unsuccessful cases when conventional root filling technique was used in anterior teeth which showed pulpal necrosis and perixadicular rarefication. In other studies where implants were used to stabilise teeth loosened by periodontal disease approximately IO per cent. of the cases showed inflammatory changes around the implant at re-examination (Souza, I954; Staegemann, I96O; Hermann, I965). In these studies, in contrast to the present one, a vital pulp had been present at the time of implantation. This difference in pulp status can possibly explain the better healing results obtained in stabilisation of teeth with periodontal disease. A later survey of long-term results will be carried out in due course. SUMMARY In I2 teeth with root fracture exhibiting excessive loosening and pulpal necrosis, the apical fragment was removed. A preformed cobalt-chromium implant was inserted through the root canal into the periapical bone replacing the apical fragment. The observation period varied from i to 3½ years. At followup examination eight of the performed operations were regarded as successful.
146
BRITISH JOURNAL OF ORAL SURGERY REFERENCES
ANDREASEN,J. O. & HJORTING-HANSEN,E. (1967). ft. Oral Surg. 25, 414. BRUGIRARD,J. & ACHARD,R. (I966). Rev. de Stomat. 67, 505. BRUNO, B. J. A. (I954). Odont. urug. 8, 251 and 31I. FERRIER, A. (196o). Schweiz. Mschr. Zahnheilk. 7o, IOOI. FRANK, A. L. (I967). J. Amer. dent. Ass. 74, 451. GRAZIDE, COULOMB,BOISSEL& PASQUE(I956). Rev. de Stomat. 57, 428. HADERUP, V. (I887). Korresp.--Bl. Zahniirz, 16, 314. HANSEN, JEs. (1966). Nordisk Klinisk Odontologi. Chapter 2o, IV. A/S Forlaget fbr Faglitteratfir, Copenhagen, 1966. HERMANN, D. (1965). Dtseh. zahndrztl. Z. 2o, 1356. LINDAHL,B. (I958). Odont. Revue. 9, IO. MICHANOWICZ,A. ]~. (1963). Oral Surg. I6, i242. ORLAY,H. G. (196o). Brit. dent. J. 108, II8. PARKER,G. D. (1956). Dent. Dig. 62, 58. SHAYKIN, J. B. (1964). ft. Amer. dent. Ass. 68, 704. SOUZA, M. (1954). Rev. odont. B. Aires. 42, 325. STACY,G. C. (1965). Brit. dent. J. 118, 2Io. STAEGEMANN,G. (1957)- Dtsch. zahndrztl. Z. 12, 15o2. STAEGEMANN,G. (196o). Dtsch. zahniirztl. Z. 15, lO94. STRINDBERG,L. Z. (1956). Acta odont, scand. I4, 133.
University Hospital, Copenhagen and Royal Dental College, Copenhagen IN a study of the events of healing in 48 cases of intra-alveolar root fractures, it was found that inflammatory changes occurred in the fracture line in 47 per cent. of the cases (Andreasen and Hjorting-Hansen, z967). A histological examination demonstrated that the origin of the inflammation was a pulpal necrosis in the coronal fragment. Most authors advocate extraction of teeth with root fracture when pulpal complications occur, but in recent years root canal treatment in such cases has been carried out with good results (Lindahl, I958; Michanowics, z963). If the fracture is located in the coronal third of the root an excessive loosening of the coronal fragment occurs. Intraradicular splinting, using a metal pin as a root canal filling to unite the two fragments, has been used as a method of stabilising the tooth (Grazide et aL, z956; Stacy, I965; Brugirard and Achard, z966). Another method has been to remove the apical fragment and replace it with a metallic implant retained in the coronal fragment (Brugirard and Achard, r966; Hansen, I966; Frank, z967). A similar implant technique has been used to stabilise teeth loosened by periodontal disease or root resection (Bruno, x954; Souza, z954; Parker, z956; Staegemann, 1957, I96O; Orlay, 196o; Ferrier, 196o; Shaykin, 1964; Hermann, I965; Frank, 1967). The purpose of the present study has been to evaluate the implant technique in cases of intra-alveolar root fractures which demonstrate pulpal complications and excessive loosening of the coronal fragment. MATERIAL AND METHODS The material consists of IO patients who had 12 intra-alveolar root fractures treated with cobalt-chromium implants. All the teeth were excessively loose, the fracture was located in the marginal third of the root, and a pulpal necrosis was present in all cases. The cobalt-chromium implants were constructed in the following way: An extracted central incisor was chosen as a phantom model and twothirds of the root was resected. A slightly tapered diamond bur (D. & Z. No. Ir8) was inserted in the root canal via a coronal access, and the bur forced through the canal to the level of the resected apex. A soft steel wire with a diameter of I'2 ram. was slightly bent and covered with softened wax. An impression was taken of the artificial root canal with the metal wire placed in the root canal in such a way that the curvature of the wire followed a palatal direction. After investment, a casting was performed in cobalt-chromium (Remanit ®). Due to the tapering of the casting a good marginal seal was created between the implant and the root surface (Fig. I, a, B, C and D). * Aided by a grant from the Danish Dental Association: 'Fonden til Stotte for Videnskabelige og Praktiske Undersogelser indenfor Tandlmgekunsten'. I4I
I42
BRITISH JOURNAL OF ORAL SURGERY
FIG. I A, From left to right: Phantom tooth model, diamond bur (D. & Z. No. xIS), soft steel wire covered with impression wax, and finished casting in cobalt-chromium. B, Cast implant inserted in phantom model, lateral view, note that the curvature of the implant follows a palatal direction. C, Frontal view. D, Note the close adaption between implant and root surface.
TREATMENT
OF
INTRA-ALVEOLAR
ROOT
143
FRACTURES
T h e following surgical p r o c e d u r e was performed. A mucoperiosteal flap was raised, a n d the apical f r a g m e n t was r e m o v e d (Fig. 2, A). T h e entire r o o t canal in the coronal f r a g m e n t was enlarged to the level o f t h e fracture line with t h e
A
B C FIG. 2 Case No. 5. A, Right upper central incisor with intra-alveolar root fracture demonstrating periapical inflammation. A mucoperiosteal flap has been raised and the apical fragment has been removed. B, Insertion of the implant. C, Radiograph immediately after insertion of the implant. TABLE
I
R E S U L T S A F T E R V I T A L L I U M I M P L A N T S IN 12 T E E T H INTRA-ALVEOLAR ROOT FRACTURES Case
number
I I 2
3 4 5 6 6 7 8
9 IO
* Tooth number z+ +z +3 -J-I
Observation period years 3 3 3 I½
I+
3 3 3
+I
Radiographic examination Periradicular radiolucency
Loosening
Fistula
_
m
+ +
-
+
+
-
+
+
m
2
+I
I+ Z+ I+ +I
Clinical examination
WITH
2
A I
3
* The figures indicate the region according to Haderup's notation: - denotes the lower jaw, + the upper jaw. If the sign is placed to the right of the figure (I + , for example), the right side is indicated, and vice versa (Haderup, I887).
BRITISH
144
JOURNAL
OF ORAL S U R G E R Y
A
B C FIG. 3 Case No. 8. A, Pre-operative conditions of intra-alveolar root fracture of both central incisors. + I demonstrates periradicular radiolucency due to inflammatory changes in the fracture line. B, Radiograph immediately after insertion of the implant in + i. C, Radiograph 31 years after operation. Note the osseous healing with a narrow radiolucent line around the implant.
A
B C FIG. 4 Case No. 4. A, Condition after insertion of implant.
B, Post-operative condition after x} years. Note radiolucent area around the fractured root surface. C, Collagenous tissue from case No. 4 covering the most apical part of the implant.
TREATMENT OF INTRA-ALVEOLAR ROOT FRACTURES
145
tapered diamond bur. A cobalt-chromium implant was inserted in the root canal and the direction of the implant was noted; a cavity was created in the alveolar bone which assured that the length of the implant exceeded the original length of the root by 2 to 6 ram. The length of the implant was adjusted to the cavity in the bone (Fig. 2, B), and in addition the length of the implant was adjusted to the level of the lingual surface of the crown. The implant was cemented in the root canal with an ordinary zinc-phosphate cement and special care was taken to remove all excess cement (Fig. 2, c). RESULTS In Table I the results of treatment of I2 teeth are shown. It is noted that the results have been favourable in 8 cases with an observation period from I to 3½ years. Clinically in these cases the teeth were firm and with a normal pochet depth. Radiographically a narrow radiolucent area was seen around the implant suggesting the presence of a layer of connective tissue (Fig. 3)- In four cases a periapical radiolucency and in two cases the presence of a fistula indicated inflammatory changes. At re-operation a leak between the post and the root canal was found. A biopsy was taken of the tissue covering the apical part of the post in one of these cases. Histological examination revealed connective tissue without inflammatory changes (Fig. 4). DISCUSSION The purpose of the operation has been to place the fulcrum of the transversal movements in a more apical position in teeth with root fractures. The clinical examination showed that this could be achieved with the implant technique. In four cases (33 per cent.) inflammatory changes were found; approximately the same failure rate as reported by Strindberg (I956), who found 35 per cent. unsuccessful cases when conventional root filling technique was used in anterior teeth which showed pulpal necrosis and perixadicular rarefication. In other studies where implants were used to stabilise teeth loosened by periodontal disease approximately IO per cent. of the cases showed inflammatory changes around the implant at re-examination (Souza, I954; Staegemann, I96O; Hermann, I965). In these studies, in contrast to the present one, a vital pulp had been present at the time of implantation. This difference in pulp status can possibly explain the better healing results obtained in stabilisation of teeth with periodontal disease. A later survey of long-term results will be carried out in due course. SUMMARY In I2 teeth with root fracture exhibiting excessive loosening and pulpal necrosis, the apical fragment was removed. A preformed cobalt-chromium implant was inserted through the root canal into the periapical bone replacing the apical fragment. The observation period varied from i to 3½ years. At followup examination eight of the performed operations were regarded as successful.
146
BRITISH JOURNAL OF ORAL SURGERY REFERENCES
ANDREASEN,J. O. & HJORTING-HANSEN,E. (1967). ft. Oral Surg. 25, 414. BRUGIRARD,J. & ACHARD,R. (I966). Rev. de Stomat. 67, 505. BRUNO, B. J. A. (I954). Odont. urug. 8, 251 and 31I. FERRIER, A. (196o). Schweiz. Mschr. Zahnheilk. 7o, IOOI. FRANK, A. L. (I967). J. Amer. dent. Ass. 74, 451. GRAZIDE, COULOMB,BOISSEL& PASQUE(I956). Rev. de Stomat. 57, 428. HADERUP, V. (I887). Korresp.--Bl. Zahniirz, 16, 314. HANSEN, JEs. (1966). Nordisk Klinisk Odontologi. Chapter 2o, IV. A/S Forlaget fbr Faglitteratfir, Copenhagen, 1966. HERMANN, D. (1965). Dtseh. zahndrztl. Z. 2o, 1356. LINDAHL,B. (I958). Odont. Revue. 9, IO. MICHANOWICZ,A. ]~. (1963). Oral Surg. I6, i242. ORLAY,H. G. (196o). Brit. dent. J. 108, II8. PARKER,G. D. (1956). Dent. Dig. 62, 58. SHAYKIN, J. B. (1964). ft. Amer. dent. Ass. 68, 704. SOUZA, M. (1954). Rev. odont. B. Aires. 42, 325. STACY,G. C. (1965). Brit. dent. J. 118, 2Io. STAEGEMANN,G. (1957)- Dtsch. zahndrztl. Z. 12, 15o2. STAEGEMANN,G. (196o). Dtsch. zahniirztl. Z. 15, lO94. STRINDBERG,L. Z. (1956). Acta odont, scand. I4, 133.