Page 219 - My FlipBook
P. 219
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REMOVING THE DECAY. 217
instrument may move in a eurve. By this means the motion of the
chisel is regulated and controlled and all danger of slipping avoided.
It will sometimes be of advantage to roughly pack the interior of the
cavity with cotton or spunk to receive the impact of the instrument
should the chisel accidentally be forced to the bottom of the cavity.
The better plan, however, in most cases, is to employ mallet force
for the cleavage of enamel unsupported by dentin. By holding the
chisel between the thumb and three fingers of the left hand and resting
the little finger of the same hand on an adjacent tooth for steadiness, a
smart but light blow of a mallet in the right hand upon the end of the
chisel will easily and painlessly cleave off portions of the enamel.
In opening cavities of small extent or limited depth upon approxi-
mal surfaces a round or inverted-cone bur will best
Fig. 166.
serve the purpose, but where caries is more exten-
sive and the surrounding enamel is unsupported by
dentin the orifice of the cavity can be more advan-
tageously enlarged by means of a delicate chisel
(shown in Fig. 1 66) the blade of which is bent at a
slight angle to the shank and all three of the edges
of which are bevelled to convert them into cutting
edges. This instrument will be found especially
useful in opening cavities of medium or larger size
on the approximal surfaces of the incisors, the point
doing the cleaving and the side edges being used to Delicate three-sided
chisel, useful for
smooth the enamel margins.
opening cavities on
After the orifice of the cavity has been sufficiently approximal sur-
faces.
enlarged to afford a full vie^v of its interior the next
stage of the operation is entered upon
Removing the Decay.
The character or consistence of the carious structure has much to
do with the method and means employed for its removal. If it be of
the semi-elastic or leathery variety so often found in the teeth of young
persons, it can be most easily removed by means of spoon-shaped or
round-bladed excavators, which being oval or circular in edge out-
line and free from marginal angles, will lift and separate the layers
witliout danger of injuring the underlying healthy dentin and with the
infliction of a minimum amount of pain. Fig. 167 illustrates this kind
of instrument in some of its forms, selected from the Darby-Perry set.
In the dark, hard variety of caries, as also in the tchite, chalky
variety, the diiferent forms of l)urs and excavators will be found best
suited for the purpose.
In tlio removal of caries care should be exercised to inflict as little
REMOVING THE DECAY. 217
instrument may move in a eurve. By this means the motion of the
chisel is regulated and controlled and all danger of slipping avoided.
It will sometimes be of advantage to roughly pack the interior of the
cavity with cotton or spunk to receive the impact of the instrument
should the chisel accidentally be forced to the bottom of the cavity.
The better plan, however, in most cases, is to employ mallet force
for the cleavage of enamel unsupported by dentin. By holding the
chisel between the thumb and three fingers of the left hand and resting
the little finger of the same hand on an adjacent tooth for steadiness, a
smart but light blow of a mallet in the right hand upon the end of the
chisel will easily and painlessly cleave off portions of the enamel.
In opening cavities of small extent or limited depth upon approxi-
mal surfaces a round or inverted-cone bur will best
Fig. 166.
serve the purpose, but where caries is more exten-
sive and the surrounding enamel is unsupported by
dentin the orifice of the cavity can be more advan-
tageously enlarged by means of a delicate chisel
(shown in Fig. 1 66) the blade of which is bent at a
slight angle to the shank and all three of the edges
of which are bevelled to convert them into cutting
edges. This instrument will be found especially
useful in opening cavities of medium or larger size
on the approximal surfaces of the incisors, the point
doing the cleaving and the side edges being used to Delicate three-sided
chisel, useful for
smooth the enamel margins.
opening cavities on
After the orifice of the cavity has been sufficiently approximal sur-
faces.
enlarged to afford a full vie^v of its interior the next
stage of the operation is entered upon
Removing the Decay.
The character or consistence of the carious structure has much to
do with the method and means employed for its removal. If it be of
the semi-elastic or leathery variety so often found in the teeth of young
persons, it can be most easily removed by means of spoon-shaped or
round-bladed excavators, which being oval or circular in edge out-
line and free from marginal angles, will lift and separate the layers
witliout danger of injuring the underlying healthy dentin and with the
infliction of a minimum amount of pain. Fig. 167 illustrates this kind
of instrument in some of its forms, selected from the Darby-Perry set.
In the dark, hard variety of caries, as also in the tchite, chalky
variety, the diiferent forms of l)urs and excavators will be found best
suited for the purpose.
In tlio removal of caries care should be exercised to inflict as little
