Page 184 - My FlipBook

182 PRELIMINARY PREPARATION OF THE TEETH.

nic oxid (" tutty powder"), wliicli also is better applied when coml)inod
Avitli glycerin or rubbed np with vasolin.
Salivary calculus is found precipitated at parts not subject to free
friction, such as the buccal surfaces of the molars, the inner faces of
the lower incisors, and it frequently invades the interstices. These
deposits also should be displaced and the
Fig. 149. surfaces polished.
The better appliances for the removal
of superficial calculus are sickle-shaped
scalers of various sizes and forms, which
are inserted beneath the free margin of
the gum, when the direction of the move-
ment should be obliquely toward the
occlusal aspect to avoid injury to the
gingival attachment with the tooth. The
consideration of the removal of deeply
Abbott's scalers.
seated salivary calculus where some
serious injury has been caused by its presence is treated of in Chap.
XIX.
Polishing- the Triangular Portion of the Interproximal Spaces.
—When this is required an efficient means is to employ gilling twine
of sizes proportioned to the space. This is applied by looping one
or more strands with a piece of floss silk, when the silk is drawn up-
ward into the triangle and then is used to pull the twine into the
space, which being armed with suitable powders is drawn to and fro
until the absence of friction indicates that the surfaces have become
smooth.

CAEE BY THE PATIENT.
Coincident with the preparation above described the patient should
be given such instruction as will tend to maintain the state of cleanli-
ness. The importance of this should be impressed as a necessary
hygienic measure to preserve the teeth. This is to be accomplished by
the use of suitable brushes and properly compounded powders. The
detergent effect of powder is principally due to the particles becoming
mixed with the film of mucus. This action breaks up the continuity
of the film, which, with the accompanying sediments, is displaced by
the friction of the brush.
The correct use of the brush requires that it be placed with some
degree of firmness upon the outer and inner faces of the teeth and then
slightly rotated. The pressure drives the bristles into the valleys, and
the rotary movement being away from the gum avoids injury to that
structure. The application of this procedure in combination with the