1. Week 3 Session 2
Anatomy Quiz & Lower Special Tray
2. Part 1
A short quiz of upper oral anatomy and
PLEASE PUT ALL NOTES AWAY
F > I
NIdentify the oral structures
lettered J > N
What did you remember?
7. Answers A to G
F. Mesiobuccal cusp
G. Mesiopalatal cusp
8. Answers H to N
H. Distobuccal cusp
I. Distopalatal cusp
J. Upper labial frenum
L. Upper right buccal frenum (Just ‘buccal
frenum’ does not count)
M. Hard palate
9. Part 2
Making an edentulous lower special
tray for ZOE (Zinc Oxide Eugenol)
10. Mark line of the ridges and outline of
Identify location for rests, in the
second premolar/first molar region
margin to be
just above the
Identify areas of undercut e.g.
below retromolar pad and block
out with wax
12. Carefully adapt a sheet of light
Do not over thin
If the cast shows through add
13. Initial trimming
14. Push the material into the sulcus
ensuring the material fully
extends into it
15. Using a sharp tool carefully trim
the material to the marked
16. Trim all around the sulcus to the
17. Make a handle approximately 20mm long, 15mm wide and
5mm thick taper towards the tip.
Flare the base of the handle to ease adaption to the base
18. Position the handle in the midline of
the anterior ridge.
The handle should be between 22mm
and 25 mm from the depth of the
It should be vertical but a slight anterior
tilt may be acceptable.
When correctly positioned the flared
edges are blended into the base
• The rest is made in the same way as the handle
although slightly shorter.
• The base is flared and the rest positioned
centrally on the ridge approximately in the
position of the second premolar/first molar.
• The rest should be a maximum of 15 mm from
the depth of the sulcus.
• If the rest is placed too far lingually it will restrict
the tongue, too far buccally will distort the
• When both rests are completed the tray is
checked and then smoothed with petroleum
jelly. This smoothes the material and acts to
seal the material to reduce surface inhibition
of the set by oxygen in the atmosphere.
• The tray is placed in a light curing box and
cured for 3 minutes. When cured the tray is
removed from the cast, the tray is turned
over and the fitting surface cured