Removable Partial Dentures Lab
Describe the process of making a custom tray - correct answer ✔-after
blocking out undercuts, put 2 layers of baseplate was over tissue (~3mm) and
3 layers over teeth (b/w 3-5mm)
-trim wax away and smooth with wax spatula
-create tissue stops (3x3mm) on non-functional cusps in on anterior in a
tripodized manner
-coat wax with vaseline and then apply triad, making sure to fill the tissue-
stops first
-trim triad and make a handle, not too high and up and out
-punch holes in triad with back of cotton-tipped applicator to make it easier to
make larger holes later with #8 round bur (1/4" apart)
-cure for 2 minutes, remove wax, then cure again for 2 minutes
-punch holes and trim edges and disinfect
-should be 3-5mm short of the vestibule
What should you do before prepping the teeth? - correct answer ✔-discuss
with the patient about what you are going to do and why (i.e. design
principles)
-answer questions
-inform the patient that a restoration involves risks and if the crown breaks
then the patient is responsible for paying for a new one
What is the order of tooth preparation? - correct answer ✔1) guiding
surfaces
2) H.O.C.
3) Rests
, *This is different then the design principles and is always on the boards
*once you make all the cuts with a coarser bur, go back and refine everything
all at once
What principles and burs are used when prepping the guiding surfaces? -
correct answer ✔-prep guiding surfaces parallel in a curve-linear fashion
-parallel minor connectors with each other and guide planes
6836 and 6856 (coarse)
8836 and 8856 (fine)
the 836 is cylindrical and the 856 gives a chamfer
What principles and burs are used when prepping the rests? - correct answer
✔-cingulum rests: use inverted diamond, 876, or 1172; must be concave
mesial/distal and convex lingual; dont touch the cingulum to maintain positivity
(confirm with explorer tip)
-occlusal rests: use #6 or 8 round carbide bur on premolars (depending on
size); #8 on molars and diamond if on a crown; must uniformly reduce 1.5mm
and be wider towards the marginal ridge and deepest in the center (spoon
shaped)
How do you check the reduction of a rest? - correct answer ✔-use 0-bite,
regisil, or occlusal wax and let set for about 5 minutes in occlusion
-use Iwanson gauge (blunt end) to check thickness of the wax (must be at
least 1.5mm)
What should you use to refine if you're working with...
1) gold
2) ceramic
Describe the process of making a custom tray - correct answer ✔-after
blocking out undercuts, put 2 layers of baseplate was over tissue (~3mm) and
3 layers over teeth (b/w 3-5mm)
-trim wax away and smooth with wax spatula
-create tissue stops (3x3mm) on non-functional cusps in on anterior in a
tripodized manner
-coat wax with vaseline and then apply triad, making sure to fill the tissue-
stops first
-trim triad and make a handle, not too high and up and out
-punch holes in triad with back of cotton-tipped applicator to make it easier to
make larger holes later with #8 round bur (1/4" apart)
-cure for 2 minutes, remove wax, then cure again for 2 minutes
-punch holes and trim edges and disinfect
-should be 3-5mm short of the vestibule
What should you do before prepping the teeth? - correct answer ✔-discuss
with the patient about what you are going to do and why (i.e. design
principles)
-answer questions
-inform the patient that a restoration involves risks and if the crown breaks
then the patient is responsible for paying for a new one
What is the order of tooth preparation? - correct answer ✔1) guiding
surfaces
2) H.O.C.
3) Rests
, *This is different then the design principles and is always on the boards
*once you make all the cuts with a coarser bur, go back and refine everything
all at once
What principles and burs are used when prepping the guiding surfaces? -
correct answer ✔-prep guiding surfaces parallel in a curve-linear fashion
-parallel minor connectors with each other and guide planes
6836 and 6856 (coarse)
8836 and 8856 (fine)
the 836 is cylindrical and the 856 gives a chamfer
What principles and burs are used when prepping the rests? - correct answer
✔-cingulum rests: use inverted diamond, 876, or 1172; must be concave
mesial/distal and convex lingual; dont touch the cingulum to maintain positivity
(confirm with explorer tip)
-occlusal rests: use #6 or 8 round carbide bur on premolars (depending on
size); #8 on molars and diamond if on a crown; must uniformly reduce 1.5mm
and be wider towards the marginal ridge and deepest in the center (spoon
shaped)
How do you check the reduction of a rest? - correct answer ✔-use 0-bite,
regisil, or occlusal wax and let set for about 5 minutes in occlusion
-use Iwanson gauge (blunt end) to check thickness of the wax (must be at
least 1.5mm)
What should you use to refine if you're working with...
1) gold
2) ceramic
