Welch Allyn Kreativ Mach 4.0, Инструкция по эксплуатации

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Page 21 990242 Rev. A
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Enamel cuts slower than dentin thus:
•
It may take
1-2 minutes
to complete a class I preparation on a molar
•
But it may take only 5 seconds to complete a class V preparation on a premolar.
⇒
Increased powder flow and air pressure will increase cutting speed, but it will also deliver more
powder which must be controlled with the high volume evacuation.
With experience you will find a comfortable balance between
cutting speed and controlling the powder flow in the mouth.
⇒
Most preparation procedures can be easily accomplished with:
•
about 60-80 PSI (619-825 kPa)
•
the powder flow set at about 3-5.
⇒
Start by using the general settings (above) and the 0.018 (0.46 mm) tip.
⇒
As you gain experience choose the nozzle size and system settings which suit your individual needs.
General Operating Procedures
The Cutting Process:
The unit performs a cutting action by impinging sharp-edged powder particles onto a surface. A
cylindrical powder/air stream emerges from the nozzle for a short distance (approximately 1.6
mm) and then diverges into a cone shape, with a seven degree included angle. Within the 1.6 mm,
the nozzle makes small holes and straight walled cuts. As one moves the nozzle away from the
work, the hole diameter or width of cut increases, and the walls become angular. The angle can be
determined with a few trials. To obtain sharp definition (as in precise cutting) use the 0.014
″
(0.36mm) diameter nozzle and keep the nozzle tip to a minimum of 0.8 mm from the work.
Cutting Speed:
The cutting speed (removal of material) increases up to a certain nozzle distance.
Vary the cutting rate by:
1) adjusting the powder flow and/or air flow.
2) using different pressure settings .
3) using different powder sizes.
4) using special type nozzles.
Etch or remove broad areas of metallic film or coatings by increasing the nozzle tip distance and
diverting the air stream at an acute angle.