Page 409 - My FlipBook
P. 409
:
REACTION OF THE PULP TO THERMAL TESTS. 407
A large proportion of persons manifest distress between 40° and
60° F.
Intolerance of heat is determined in the same manner, except that
it is frequently necessary to isolate the tooth by applying rubber dam,
since the gum usually begins to be pained at 130° F. In all cases in
Avhich the cementum is exposed isolation is required, since the cemen-
tum may react at slight variations from blood heat. To secure exact-
ness in any case isolation is better than an open test.
When disturbance of the pulp occurs from the extended progress
of caries the reaction of the pulp to changes of temperature is usually
marked, and the variation from the normal rate is indicative of the
degree of disorder of this organ. The response occurs to temperatures
both below and above the normal rate. When the irritation of the
pulp consequent upon its exposure is slight, the reaction is principally
to cold, the degree apparently depending upon the extent of the hyper-
emia. When the reaction to heat is marked, congestion of the organ
is threatening.
Disorders of the pulp appear to excite other anatomical elements of
the teeth, as is indicated by reaction to cold and heat being more
immediate than is the case with the sound teeth. A more exact
degree of temperature reaction may also be secured when this condi-
tion exists.
It is essential in making tests that a carious cavity be closed by a
pledget of wet cotton. This is sufficient to exclude the disturbing effect
of the hypersensitive dentin, since water is a nearly absolute non-con-
ductor.
Examples from practice to illustrate : 1. Cavity rate, + 110° — 80°,
when protected as above + 130° - 60°. Here the normal rate was
+ 131° - 58°. 2. Cavity rate, + 108° - 90° ; normal rate, + 134°
-65°. 3. Cavity, 4 120° - 50° ; normal, 128° -48°.
The following table of normal rates shows the relation between the
point of heat reaction of the pulp and the degree of its reaction upon
the abstraction of heat
+ 152° — 41° + 133° — 66°
+ 150° — 40° + 131° — 63°
+ 144° _ 48° + 130° — 55°
+ 144° — 32° + 130° — 72°
-f- 140° — 48° + 128° — 48°
+ 140° — 46° + 126° — 64°
+ 140° — 46° + 124° — 76°
+ 140° — 32° + 124° — 60°
+ 140° — 56° + 122° — 75°
+ 134° — 58° + 120° —72"
+ 134° — 65° + 118° — 74°
+ 134° — 60°
REACTION OF THE PULP TO THERMAL TESTS. 407
A large proportion of persons manifest distress between 40° and
60° F.
Intolerance of heat is determined in the same manner, except that
it is frequently necessary to isolate the tooth by applying rubber dam,
since the gum usually begins to be pained at 130° F. In all cases in
Avhich the cementum is exposed isolation is required, since the cemen-
tum may react at slight variations from blood heat. To secure exact-
ness in any case isolation is better than an open test.
When disturbance of the pulp occurs from the extended progress
of caries the reaction of the pulp to changes of temperature is usually
marked, and the variation from the normal rate is indicative of the
degree of disorder of this organ. The response occurs to temperatures
both below and above the normal rate. When the irritation of the
pulp consequent upon its exposure is slight, the reaction is principally
to cold, the degree apparently depending upon the extent of the hyper-
emia. When the reaction to heat is marked, congestion of the organ
is threatening.
Disorders of the pulp appear to excite other anatomical elements of
the teeth, as is indicated by reaction to cold and heat being more
immediate than is the case with the sound teeth. A more exact
degree of temperature reaction may also be secured when this condi-
tion exists.
It is essential in making tests that a carious cavity be closed by a
pledget of wet cotton. This is sufficient to exclude the disturbing effect
of the hypersensitive dentin, since water is a nearly absolute non-con-
ductor.
Examples from practice to illustrate : 1. Cavity rate, + 110° — 80°,
when protected as above + 130° - 60°. Here the normal rate was
+ 131° - 58°. 2. Cavity rate, + 108° - 90° ; normal rate, + 134°
-65°. 3. Cavity, 4 120° - 50° ; normal, 128° -48°.
The following table of normal rates shows the relation between the
point of heat reaction of the pulp and the degree of its reaction upon
the abstraction of heat
+ 152° — 41° + 133° — 66°
+ 150° — 40° + 131° — 63°
+ 144° _ 48° + 130° — 55°
+ 144° — 32° + 130° — 72°
-f- 140° — 48° + 128° — 48°
+ 140° — 46° + 126° — 64°
+ 140° — 46° + 124° — 76°
+ 140° — 32° + 124° — 60°
+ 140° — 56° + 122° — 75°
+ 134° — 58° + 120° —72"
+ 134° — 65° + 118° — 74°
+ 134° — 60°
