Since only 46% of prepared molars
exhibit an adequate resistance form,54 according to
Goodacre et al.,51 at least 4 mm is recommended as the
minimal preparation height. If this height is not
available, then auxiliary retention and resistance
features should be incorporated. Therefore, with
increasing OVD, it is possible to crown teeth with an
original clinical crown height of 3 mm without
adjunctive therapy. As a result, it appears that the final
preparation height is a critical determinant of the need
and the magnitude of the OVD increase.