In the pre-transfer stage, grasp the used instrument
firmly using the little finger as shown in figure 4-34
(step C). Sometimes, you may prefer to use the last two
or even three fingers to receive the used instruments.
Immediately following this action, you carry out the
In this stage, place the next instrument into the
dentist's hand with the working end positioned toward
the treatment site, as shown in figure 4-34 (step D).
When the treatment site is located on the maxillary
arch, point the working end of the instrument up.
Likewise, when the treatment site is on the mandibular
arch, position the working end down. Do not release
your grip of the new instrument until the dentist has
firmly grasped the instrument. If the instruments
become tangled during the exchange, this is usually
caused by failure to parallel the handles before the
exchange. The exchange of all instruments is done
with firm, deliberate movements to give both the
dentist and the assistant the feeling of confidence and
to eliminate lost time and motion. Return the used
instrument to its original position on the instrument
tray and prepare to repeat the procedure with the next
Refer to figure 4-35 for an overhead view (left-
handed) of an instrument exchange during patient
treatment. When you assist from the right side of the
Figure 4-35.Overhead view of instrument exchange.
patient, use your right hand in the same manner
described for the left hand.
O T H E R I N S T R U M E N T E X C H A N G E
techniques may have to be used depending on what
type of instrument is being exchanged. These other
techniques have been described in "Oral Surgery
Assistance," Volume 2, chapter 5.
Handpiece and Bur Exchange
The dental handpiece can be exchanged for
another instrument in the same manner described in
this section. If two handpieces are exchanged, exercise
caution to avoid tangling the hoses during the
During the operative procedure, the dentist holds
the handpiece firmly over the patient's upper chest in
the transfer zone, and then the assistant will loosen and
remove the bur. The assistant next retrieves the bur
that was selected by the dentist and places it into the
dental handpiece and secures it. Always give the bur a
gentle tug to ensure that it is firmly seated in the
handpiece. If the dentist uses a different instrument
between bur exchanges, change the bur outside the
transfer zone, usually over the tray setup.
If the dentist changes handpieces and requires an
exchange of burs in the returned handpiece, be sure to
use the lock-out toggle switch for the handpiece before
attempting to change burs. If you fail to do this, you
could cause harm to yourself when the provider steps
on the foot control to activate the other handpiece.
Preparing and Passing Materials
Dental materials are exchanged at the patient's
chin in the transfer zone. This prevents materials from
being dropped on the patients face. Small amounts of
dental materials may be mixed and passed on a glass
slab, paper pad, or dappen dish.
As a dental assistant, you must prepare dental
materials at the proper time during the procedure. A
material mixed too soon does not allow sufficient
handling time. Knowing when to mix is equally as
important as knowing how to mix. As with
instruments, knowing the routine of the procedure lets
you anticipate when the dentist will need the specific
material. You should have the mixing equipment
ready and the material in position and in place slightly
before the time it is needed. Begin mixing only when
you know the dentist is ready.