Mark II Instruction Manual - Whip Mix

error was not introduced in the laboratory.
He can then re-evaluate his procedure
to determine the source of error.
In other words, if the restoration fits the
mounted casts but not the mouth, the
technician cannot be expected to participate
in the additional cost of remakes
not attributed to laboratory procedures.
CLASSIFICATIONS OF
OCCLUSAL CARVINGS
The following classification of occlusal
carvings as illustrated in figure 82 enables
the dentist to specify to the laboratory
the relative amount of time and effort
he desires the laboratory to expend (and
consequently the laboratory fee) to fabricate
the prescribed occlusion.
Alloy Restorations
Class A – Refined Occlusal Carving
The restoration is fabricated in the manner
the technician might employ when
using a simple crown and bridge hinge
mechanism. When the occlusion is
semi-developed, the technician simply
bruxes the instrument to burnish away
eccentric interferences and refines the
anatomy of the remaining wax. Eccentric
irritations are removed from the
occlusion in the laboratory. This is the
application of principles of occlusion in
its simplest form and consequently is a
minimum fee laboratory service.
Class AA – Modified Drop Wax
Basically, this is a Class A carving
with more refinement. The technician
carves in supplemental grooves and
then accentuates triangular, cuspal and
marginal ridges with the drop wax technique.
The ultimate appearance will be
similar to a Class AAA carving. A Class
AA carving requires more laboratory
time than a Class A carving and so the
laboratory fee should reflect 10% to
30% increase in the labor factor of the
Class A carving.
fig. 82
Class AAA – Complete Drop Wax
The drop wax technique is employed to
restore the total occlusal surface and
all restored axial surfaces to obtain the
maximum esthetic cusp height, optimum
cusp distribution, and to harmonize
the occlusal anatomy with condylar
paths of movement. This type of occlusal
fabrication requires more time and
skill than a Class A or Class AA carving
and consequently the laboratory
fee reflects a 50% to 100% increase in
the labor factor of a Class A carving.
However, this can only be done on a
restoration involving extensive tooth reduction.
For example, if the restorations
are MOD inlays or onlays with minimum
tooth reduction, the cusp distribution
has already been accomplished and the
laboratory only needs to do the fill-inprocedures
of the drop wax technique.
Consequently, a Class AA or AA+ carving
would suffice.
Centric Contacts
The character of the centric contacts
must produce axial loading of the teeth.
This can be accomplished by:
1. Point Contact (•). There is an absence
of contacting inclines. Centric
stops are on high spots or low
spots of cusps.
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