Page 41 - My FlipBook

OUTLINE FORM 37

Its maximum application is found in the management of small
cavities where the ravages of decay have not yet carried the out-
line of the cavity to areas not subject to primary enamel dissolu-
tion.
The abuses of extension for prevention result in much unneces-
sary loss of tooth substance, while its sane and legitimate use is one
of the most important factors in tooth salvage.
Dangers of Increased Cavity Outline. The danger of secondary
caries increases in each mouth proportionately as the aggregate
length of cavity outline is increased.
To Illustrate. If the total length of cavity outline of all fillings
in a mouth is doubled by the increase in number of fillings the
liability to secondary caries is doubled, all else being equal. For
that reason each individual cavity should have its outline as short
as permissible.
The laying of cavity outline in locations not susceptible to pri-
mary caries will materially decrease the liability to recurrent de-
cay, even though the aggregate cavity outline in the mouth is
thereby greatly lengthened. An aggregate cavity outline of two
feet is preferable to a total of one foot, provided the additional
length has been caused to extend to locations not liable to caries.