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Filling the Root Canals of Molar Teeth with Silver Wires
Filling the root canals of molar teeth with silver wires M . B. A ueibach, D .D .S ., N ew Yoik
Clinical success with root canal treat ment of molars justifies a more frequent use of endodontic procedures for the molars. Nature aids the dentist in his work with molars as well as with an terior teeth provided that the proper precautions are observed and the proper procedures are employed. In the past, the very thought of endo dontic treatment of a molar has alarmed many dentists, in whose minds a sort of psychological barrier was set up against such treatment. A proper rationale of treatment assiduously adhered to re moves the mental block. The practitioner learns that the molar can be treated with equally as satisfactory results as anterior teeth. Dentists agree that the patient’s own teeth are preferable to any restoration, that a fixed bridge is preferable to a partial denture and that a partial den ture is preferable to a full denture. The proper endodontic treatment of an in volved molar may well mean, therefore, the difference in a patient’s mouth be tween the use of one type of restoration and a less favorable one. Most of the recent contributions to the * endodontic literature have been directed toward the therapeutic aspect. The as sumption seems to be that all operators are equally qualified in the technical procedures. There has been a tendency to stress the reduction of treatment time 270
rather than to discuss sound operative methods which, once perfected, could in themselves decrease dependency on ther apeutic medications. Therapeutic meas ures have come to be stressed more and more as the panacea for all root canal problems, while the requirements for operative technics have become less and less exacting. It is the author’s belief that the antibiotics should be employed as an auxiliary measure rather than as the main course of treatment. As in surgery, the operative procedures play the major part in therapy, with the antibiotic med ications acting in a supporting role. As operative procedures become sounder, there is less dependence on medications. The ultimate goal in root canal ther apy is to obliterate the root canal space. In all root canal fillings two materials are employed: (1) a solid material to fill the bulk of the space and (2) a semi solid material to fill the dentinal tubules and the spaces that are not reached by the solid material. When gutta-percha and chloropercha are used, the gutta percha cone is the solid material while the chloropercha is the semisolid mate rial. In the procedures for silver wire fillings, the silver wire is the solid ma terial and the silver cement is the semi solid material.
Assistant professor of pulp canal therapy, New York University, College of Dentistry.
A U E R B A C H . . . V O L U M E 46, M A R C H 1953 • 271
Fig. 1 • Silver wire, held by H ow e pliers, being fitted to canal. W hen fitted, wire is measured to height of cusp, as illustrated
Gutta-percha in combination with chloropercha is one of the oldest sub stances used for root canal fillings and in most respects fulfills the requirements for an ideal root canal filling. It is in the filling of extremely narrow canals that gutta-percha loses its advantages. Nar
row canals are found in upper first bi cuspids, lower anterior teeth, mesial can als of lower molars and buccal canals of upper molars. In these canals the gutta percha points tend to buckle, leaving a canal filled primarily with chloropercha. The lack of solidity may permit the en trance of tissue fluids into the canals. For such extremely narrow root canals, pro cedures in which silver wire fillings are used have been developed. Silver wire fillings, properly placed, have been found to be more accurate, easier to manipu late and generally superior to gutta percha in these special cases. The silver wire filling has become the filling of choice in these narrow canals. The use of metals for the filling of root canals dates back to 1830 when Hudson of Philadelphia employed gold for this purpose. For a long time the use of silver cones was advocated because of what was believed to be a bactericidal effect resulting from the oligodynamic action of silver. In 1933, Jasper1 devel oped silver cones which corresponded in size with root canal instruments.
I. Jasper, E. A. Root-canal therapy in modern den tistry. D. Cosm os 75:823 (Sept.) 1933.
Fig. 3 • M easurem ent control envelope. Length of silver wire is recorded, and wire is placed in envelope. Additional lines provide for cor rected measurements
M £ S iO - BUCCAL
Fig. 2 • Diagram of roentgenogram of silver wires fitted into canals
P iS T A t
M C S iO - U N G U a t
272 • T H E J O U R N A L O F THE A M E R IC A N D E N T A L A S S O C IA T IO N
In the past, several difficulties were encountered in the use of silver wires. The major difficulty was that of confin ing the silver wire to the root canal. The wire has often been observed to pass through the apical foramen with a re sultant overfilling. This overfilling is not necessarily harmful since silver is com patible with periapical tissues. Since teeth move in function, however, the protruding portion of the silver wire can act as a source of irritation and result in pain. Periapical regions of infection have been known to result from such irritation. Another difficulty encountered was the management of the portion of the wires left protruding into the pulp chamber. This was a serious problem for two rea sons : (1) Any bending of this portion of the wire with an instrument may cause a protrusion of the point beyond the apical foramen. (2) If the coronal ex tension of the silver wire is not reduced
by cutting or bending, the entire wire may be loosened or dislodged by instru mentation when the tooth is being pre pared for a restoration. For these problems a solution has been found which has served satisfactorily in facilitating the filling of root canals in molars. When all the prefilling phases of endodontic treatment have been com pleted and the tooth meets all the re quirements indicating that it is ready to receive the filling, silver points are fitted to the canals. The silver points, already sterilized, are kept sterile by immersion in germicidal solution. Throughout this procedure the silver wires are regarded as sterile instruments and must be re sterilized from time to time to insure the maintenance of asepsis. The final success of the root canal filling depends on the selection, adjust ment and adaptation of the silver wires at this stage. Each wire must extend to
Fig. 4 • L e ft: Splinter forceps. Long, tapering beaks perm it handling of silver wires in pulp chamber. C en ter: Splinter forceps grasping fitted silver wire at canal opening, ready to withdraw wire. R ig h t: T hree silver wires ready to be cem ented after being measured for each canal from apex to canal opening at floor of pulp cham ber
A U E R B A C H . . . V O L U M E 46, M A R C H 1953 • 273
Fig. 5 • L e ft: Fitted wire cem ented into canal. R ig h t: Diagram of roen tgen ogram ; the three wires have been cem ented into canals
the apex and must fit snugly. Each wire must fill the canal as completely as pos sible in length as well as in width. Each wire, when finally adapted, requires pressure to force it to the apex, so that no pressure which may be applied later will cause it to pass through the periap ical foramen. During this period of adjustment, the wires are handled with a pair of pliers (Howe pliers), so that pressure can be applied (Fig. 1). A wire is fitted for each of the three canals, and a roentgenogram is taken to check the apical fit (Fig. 2 ). When the roentgenogram shows that the three wires fit the canals satisfactorily, they are removed from the tooth. Each wire is removed with the Howe pliers, with the beaks held at the height of a cusp. The wire is held against a measure ment guide envelope designed for this purpose (Fig. 3 ). The length is recorded, a right angle bend is made at the beaks of the pliers, and the wire is placed in the envelope. When this has been done for all three wires, the dentist has a re corded measurement of the three wires and the wires themselves in the envelope.
The dentist is now ready to start the next stage in preparing the silver wires for final cementation. Each wire is pre pared separately. With the Howe pliers, the silver wire is firmly placed into its canal. Then the Howe pliers are laid aside, and the splinter forceps is used (Fig. 4, left). This instrument has long tapering beaks and a locking handle which permits locking the wire in the beaks. The wire is grasped at the open ing of the canal at the floor of the pulp chamber (Fig. 4, center). The beaks are locked and the wire is withdrawn. Next, the wire is bent at the tip of the beaks and then cut. A slight curved extension must be allowed so that the wire can be grasped again. When this operation has been completed for the other wires in turn, there are three silver wires, each well adapted to its canal, snug-fitting and reaching without excess from the apex to the floor of the pulp chamber (Fig. 4, right). There is now no danger of over filling nor of excess wire in the pulp chamber. The wires are placed in the sterilizing solution while the silver ce ment is being prepared.
274 • T H E J O U R N A L Ô F T H E A M E R IC A N D EN T A L A S S O C IA T IO N
The silver cement is mixed to the con
forceps with a pen grasp, passed through
sistency of zinc oxyphosphate cement prepared for cementing an inlay. The cement is carried to the canal on paper
ered completely and is placed firmly in position in the canal (Fig. 5, left). This
points, and the walls o f the canal are
process is repeated for the other silver
lined with it carefully. Previously, root
wires. W h en the positions of the wires have been checked by means of roent
canal pluggers or files were used for this purpose. It was observed, however, that the cement was improperly distributed
the mix o f silver cement so that it is cov
genograms, the pulp chamber is filled
and that much o f it was removed on the
with cement (Fig. 5, right). W hen the objectives are understood,
instrument at withdrawal. Paper points, which are narrower than the canal, ap
endodontic procedures can be systema tized in the same manner in which most
pear to serve this purpose best. O n e silver
dentists systematize their technics in other branches o f dentistry. Definite ob jectives in filling the root canals of a
wire is now removed from the steriliz ing solution by means of cotton pliers and dried on a sterile gauze pad. It is picked up in the beaks of the splinter
molar can be achieved with a systematic use of instruments and materials.
Effects of various instruments on enamel walls Edmund V. Street, D.D.S., San Francisco
As yet little information has been pub lished concerning the effects produced by various cutting instruments on the surfaces o f the enamel walls of cavities. It appears that most of the direct ob servations
and
the
comments
in
the
literature have been based on clinical experience only and that most of the quotations have been taken from em pirical statements. Though occasionally opinions have been expressed as to the treatment of enamel walls with chisels and stones, references to the use of burs have ap peared rarely. O n this subject Arthur B.
American Textbook of Operative Dentistry commented:
Gabel1 in
the
Some operators prefer to plane the enamel walls and bevel the cavosurface angles with stones and finishing burs, feeling that this method gives a smoother surface. The ex periments of some investigators, however, seem to show that these methods have no advantage over the chisel or its equivalent. In fact, they conclude that, unless special care as to direction of rotation of the stone is taken, the result is far inferior to that obtained with the chisel. The rods break out of the wall if the stone is rotated from the dentin toward the outer enamel surface. In addition, the abrasives produce scratches in the surface which require polishing in order
Associate clinical professor of operative dentistry, College of Dentistry, University of California. I. Ward, Marcus L. American textbook of operative dentistry. Philadelphia, Lee & Febiger, 1940, p. 240-242.
Clinical success with root canal treat ment of molars justifies a more frequent use of endodontic procedures for the molars. Nature aids the dentist in his work with molars as well as with an terior teeth provided that the proper precautions are observed and the proper procedures are employed. In the past, the very thought of endo dontic treatment of a molar has alarmed many dentists, in whose minds a sort of psychological barrier was set up against such treatment. A proper rationale of treatment assiduously adhered to re moves the mental block. The practitioner learns that the molar can be treated with equally as satisfactory results as anterior teeth. Dentists agree that the patient’s own teeth are preferable to any restoration, that a fixed bridge is preferable to a partial denture and that a partial den ture is preferable to a full denture. The proper endodontic treatment of an in volved molar may well mean, therefore, the difference in a patient’s mouth be tween the use of one type of restoration and a less favorable one. Most of the recent contributions to the * endodontic literature have been directed toward the therapeutic aspect. The as sumption seems to be that all operators are equally qualified in the technical procedures. There has been a tendency to stress the reduction of treatment time 270
rather than to discuss sound operative methods which, once perfected, could in themselves decrease dependency on ther apeutic medications. Therapeutic meas ures have come to be stressed more and more as the panacea for all root canal problems, while the requirements for operative technics have become less and less exacting. It is the author’s belief that the antibiotics should be employed as an auxiliary measure rather than as the main course of treatment. As in surgery, the operative procedures play the major part in therapy, with the antibiotic med ications acting in a supporting role. As operative procedures become sounder, there is less dependence on medications. The ultimate goal in root canal ther apy is to obliterate the root canal space. In all root canal fillings two materials are employed: (1) a solid material to fill the bulk of the space and (2) a semi solid material to fill the dentinal tubules and the spaces that are not reached by the solid material. When gutta-percha and chloropercha are used, the gutta percha cone is the solid material while the chloropercha is the semisolid mate rial. In the procedures for silver wire fillings, the silver wire is the solid ma terial and the silver cement is the semi solid material.
Assistant professor of pulp canal therapy, New York University, College of Dentistry.
A U E R B A C H . . . V O L U M E 46, M A R C H 1953 • 271
Fig. 1 • Silver wire, held by H ow e pliers, being fitted to canal. W hen fitted, wire is measured to height of cusp, as illustrated
Gutta-percha in combination with chloropercha is one of the oldest sub stances used for root canal fillings and in most respects fulfills the requirements for an ideal root canal filling. It is in the filling of extremely narrow canals that gutta-percha loses its advantages. Nar
row canals are found in upper first bi cuspids, lower anterior teeth, mesial can als of lower molars and buccal canals of upper molars. In these canals the gutta percha points tend to buckle, leaving a canal filled primarily with chloropercha. The lack of solidity may permit the en trance of tissue fluids into the canals. For such extremely narrow root canals, pro cedures in which silver wire fillings are used have been developed. Silver wire fillings, properly placed, have been found to be more accurate, easier to manipu late and generally superior to gutta percha in these special cases. The silver wire filling has become the filling of choice in these narrow canals. The use of metals for the filling of root canals dates back to 1830 when Hudson of Philadelphia employed gold for this purpose. For a long time the use of silver cones was advocated because of what was believed to be a bactericidal effect resulting from the oligodynamic action of silver. In 1933, Jasper1 devel oped silver cones which corresponded in size with root canal instruments.
I. Jasper, E. A. Root-canal therapy in modern den tistry. D. Cosm os 75:823 (Sept.) 1933.
Fig. 3 • M easurem ent control envelope. Length of silver wire is recorded, and wire is placed in envelope. Additional lines provide for cor rected measurements
M £ S iO - BUCCAL
Fig. 2 • Diagram of roentgenogram of silver wires fitted into canals
P iS T A t
M C S iO - U N G U a t
272 • T H E J O U R N A L O F THE A M E R IC A N D E N T A L A S S O C IA T IO N
In the past, several difficulties were encountered in the use of silver wires. The major difficulty was that of confin ing the silver wire to the root canal. The wire has often been observed to pass through the apical foramen with a re sultant overfilling. This overfilling is not necessarily harmful since silver is com patible with periapical tissues. Since teeth move in function, however, the protruding portion of the silver wire can act as a source of irritation and result in pain. Periapical regions of infection have been known to result from such irritation. Another difficulty encountered was the management of the portion of the wires left protruding into the pulp chamber. This was a serious problem for two rea sons : (1) Any bending of this portion of the wire with an instrument may cause a protrusion of the point beyond the apical foramen. (2) If the coronal ex tension of the silver wire is not reduced
by cutting or bending, the entire wire may be loosened or dislodged by instru mentation when the tooth is being pre pared for a restoration. For these problems a solution has been found which has served satisfactorily in facilitating the filling of root canals in molars. When all the prefilling phases of endodontic treatment have been com pleted and the tooth meets all the re quirements indicating that it is ready to receive the filling, silver points are fitted to the canals. The silver points, already sterilized, are kept sterile by immersion in germicidal solution. Throughout this procedure the silver wires are regarded as sterile instruments and must be re sterilized from time to time to insure the maintenance of asepsis. The final success of the root canal filling depends on the selection, adjust ment and adaptation of the silver wires at this stage. Each wire must extend to
Fig. 4 • L e ft: Splinter forceps. Long, tapering beaks perm it handling of silver wires in pulp chamber. C en ter: Splinter forceps grasping fitted silver wire at canal opening, ready to withdraw wire. R ig h t: T hree silver wires ready to be cem ented after being measured for each canal from apex to canal opening at floor of pulp cham ber
A U E R B A C H . . . V O L U M E 46, M A R C H 1953 • 273
Fig. 5 • L e ft: Fitted wire cem ented into canal. R ig h t: Diagram of roen tgen ogram ; the three wires have been cem ented into canals
the apex and must fit snugly. Each wire must fill the canal as completely as pos sible in length as well as in width. Each wire, when finally adapted, requires pressure to force it to the apex, so that no pressure which may be applied later will cause it to pass through the periap ical foramen. During this period of adjustment, the wires are handled with a pair of pliers (Howe pliers), so that pressure can be applied (Fig. 1). A wire is fitted for each of the three canals, and a roentgenogram is taken to check the apical fit (Fig. 2 ). When the roentgenogram shows that the three wires fit the canals satisfactorily, they are removed from the tooth. Each wire is removed with the Howe pliers, with the beaks held at the height of a cusp. The wire is held against a measure ment guide envelope designed for this purpose (Fig. 3 ). The length is recorded, a right angle bend is made at the beaks of the pliers, and the wire is placed in the envelope. When this has been done for all three wires, the dentist has a re corded measurement of the three wires and the wires themselves in the envelope.
The dentist is now ready to start the next stage in preparing the silver wires for final cementation. Each wire is pre pared separately. With the Howe pliers, the silver wire is firmly placed into its canal. Then the Howe pliers are laid aside, and the splinter forceps is used (Fig. 4, left). This instrument has long tapering beaks and a locking handle which permits locking the wire in the beaks. The wire is grasped at the open ing of the canal at the floor of the pulp chamber (Fig. 4, center). The beaks are locked and the wire is withdrawn. Next, the wire is bent at the tip of the beaks and then cut. A slight curved extension must be allowed so that the wire can be grasped again. When this operation has been completed for the other wires in turn, there are three silver wires, each well adapted to its canal, snug-fitting and reaching without excess from the apex to the floor of the pulp chamber (Fig. 4, right). There is now no danger of over filling nor of excess wire in the pulp chamber. The wires are placed in the sterilizing solution while the silver ce ment is being prepared.
274 • T H E J O U R N A L Ô F T H E A M E R IC A N D EN T A L A S S O C IA T IO N
The silver cement is mixed to the con
forceps with a pen grasp, passed through
sistency of zinc oxyphosphate cement prepared for cementing an inlay. The cement is carried to the canal on paper
ered completely and is placed firmly in position in the canal (Fig. 5, left). This
points, and the walls o f the canal are
process is repeated for the other silver
lined with it carefully. Previously, root
wires. W h en the positions of the wires have been checked by means of roent
canal pluggers or files were used for this purpose. It was observed, however, that the cement was improperly distributed
the mix o f silver cement so that it is cov
genograms, the pulp chamber is filled
and that much o f it was removed on the
with cement (Fig. 5, right). W hen the objectives are understood,
instrument at withdrawal. Paper points, which are narrower than the canal, ap
endodontic procedures can be systema tized in the same manner in which most
pear to serve this purpose best. O n e silver
dentists systematize their technics in other branches o f dentistry. Definite ob jectives in filling the root canals of a
wire is now removed from the steriliz ing solution by means of cotton pliers and dried on a sterile gauze pad. It is picked up in the beaks of the splinter
molar can be achieved with a systematic use of instruments and materials.
Effects of various instruments on enamel walls Edmund V. Street, D.D.S., San Francisco
As yet little information has been pub lished concerning the effects produced by various cutting instruments on the surfaces o f the enamel walls of cavities. It appears that most of the direct ob servations
and
the
comments
in
the
literature have been based on clinical experience only and that most of the quotations have been taken from em pirical statements. Though occasionally opinions have been expressed as to the treatment of enamel walls with chisels and stones, references to the use of burs have ap peared rarely. O n this subject Arthur B.
American Textbook of Operative Dentistry commented:
Gabel1 in
the
Some operators prefer to plane the enamel walls and bevel the cavosurface angles with stones and finishing burs, feeling that this method gives a smoother surface. The ex periments of some investigators, however, seem to show that these methods have no advantage over the chisel or its equivalent. In fact, they conclude that, unless special care as to direction of rotation of the stone is taken, the result is far inferior to that obtained with the chisel. The rods break out of the wall if the stone is rotated from the dentin toward the outer enamel surface. In addition, the abrasives produce scratches in the surface which require polishing in order
Associate clinical professor of operative dentistry, College of Dentistry, University of California. I. Ward, Marcus L. American textbook of operative dentistry. Philadelphia, Lee & Febiger, 1940, p. 240-242.