Course Outline DL 211 (Laboratory) Spring : 2002

Session No.1 (2/1/02)
1. Reading assignment - Waxing the denture base, waxing the palate, preparing the posterior palatal seal (postdam). Section F, P.73 - 80 of AFP Vol 11. Study centric occlusal views on P.65, 66, 67 of AFP and compare to your set-up.
2. Lecture Notes:
A. Posterior palatal seal (Postdam).
(a) Butterfly type.
1. 0.5 deep in center of palate.
2. 1 mm deep from beginning to center of palate.
3. 1 mm wide at beginning ( hamular notch).
4. 5 mm wide in widest part.
5. 2 mm wide in center of palate.
(b) Purpose of post dam.
1. Compensate for shrinkage of acrylic.
2. Improve retention.
3. May be made in impression by dentist.
(c) Constructed at vibrating line.
(d) Use right and left hamular notches and fovea - draw a line straight from hamular notch to hamular notch thru the fovea. This line is the location of the posterior part of the palatal seal.
(e) How to locate the vibrating line in the oral cavity.

Session No.2 (2/8/02)
(1) Reading assignment - P. 84 (2) Relief areas. Section G (P.80 - 81).
(2) Lecture Notes:                                                         A. Palatal Relief. (These areas may require relief):
1. Incisive papilla
2. Median palatine raphae
3. Tori formations
B. How to create the relief:
1. Mark area to relieve with a wax pencil.
2. Cut foil to shape.
3. Glue foil into palate.
C. Flasking (Use flask and model to explain            procedures).
1. Bottom part.
a. Check for clearance. (Sides and top of flask)
b. Knock-out plate
c. No stone in tongue space on lower flasks.
2. Middle part.
3. Top part (cap)

Session No.3 (2/15/02)
(1) Reading assignment - Wax elimination & mold preparation, Characterizing denture base resins, mixing and packing acrylic, placing denture identification, processing denture resins.
(2) Lecture Notes:(Wax elimination and mold preparation).
1. Place in boiling water for 4.5 minutes.
a. Insufficient time results in teeth being removed from the mold with the wax.
b. Too much time causes the wax to turn liquid and soak into the mold.
2. Three tanks are best.
a. Tank No.1 remove bulk wax.
b. Tank No.2 detergent rinse.
1. Use a detergent solution and denture brush to lightly scrub mold.
c. Tank No.3 is hot - clean water rinse.
1. Do not use last 1/4 inch of water in dipper. Liquid wax is floating here.
d. Replace teeth that have come loose.
1. Use tweezers to replace teeth into their index.
3. Tin foil substitute. (Prevents resin from bonding to teeth)
a. Case must be hot, but no steam or water on stone mold.
b. No tin foil substitute on teeth.
1. Teeth will not bond to denture base if tin foil is on teeth.
c. No more than 3 brush strokes per area.
4. Mixing acrylic.
a. Liquid first.
b. Ratio 10/30.
c. Mix and cover (two times).
1. Cover prevents evaporation of liquid.
d. When acrylic no longer sticks to side of mixing container and snaps when pulled apart, it is ready to pack.
e. Place gingitone around necks of teeth if desired.
1. Use liquid powder - liquid powder technique.
5. Packing acrylic.
a. Use overfill method.
b. Pack acrylic around teeth with fingers.
c. Use two sheets of wet cellophane between mold halves.
d. Trial pack a minimum of three times, more if necessary.
e. Remove cellophane before final closure.
f. Place case in denture press.
6. Curing acrylic.
a. Long cure
1. 165 degrees for 8 hours.
b. Short cure
1. 165 for 1 hour.
2. Boil for 1/2 hour.
c. Cool to room temperature before deflasking.

Session No.4 (2/22/02)
(1) Reading Assignment - Deflasking. P.95 - 106 of AFP Vol 11.
(2) Lecture Notes: (Deflasking)
1. Remove lid.
2. Strike knockout ring with wood or rawhide mallet.
3. Remove bottom half of flask.
4. Drive investment through top half of flask.
5. Make cuts in cuspid and heel areas with plaster saw.
6. Using your lab knife as a wedge, place the knife blade into the saw cuts and bread away the investment. Remove the plaster from the model first. Note: More than four cuts will be required on some cases.
7. Do not break casts. They must be rearticulated.
(3) Review for quiz No.1.

Session No.5 (3/1/02) * Quiz No.1.

Session No.6 (3/8/02)
(1) Reading Assignment - Remounting and selective grinding. P.97 - 106.
(2) Lecture Notes: (Selective Grinding)
A. Teeth move during festooning and packing.
1. Correct occlusal discrepencies before
removing dentures from casts.
a. Remount dentures on articulator (Use
mounting indexes).
b. Correct processing errors by selective
grinding:
1.Restore vertical (Deepen fossa, do
not grind on cusps).
2. Perfect working & balancing (Rull of
"BULL"for working side).
B. Mill in the occlusion.
1. Cover occlusal surfaces with milling paste
(Abrasive paste).
C. Two types of milling paste:
1. One type for porcelain teeth.
2. One type for acrylic teeth.

Session No.7 (3/15/02)

(1) Lecture Notes:Remounting Index (A record of the facebow transfer).
A. Allows the remount of the finished denture in
the same relationship as original facebow
transfer).
B. Reasons for the remount:
1. Teeth not occluding correctly in the mouth.
2. To many additional corrections.
C. How to make an index for remounting:
1. Use a remounting jig or boxing wax
shaped around a mounting plate to
support a mixture of plaster.
2. Close upper member of articulator, with
denture attached, into plaster and
cover the incisal and occlusal surfaces
with approximately 3 mm of plaster.
3. Store index for future use.

(2) Review for midterm exam.

Session No.8 (3/22/02)
* Midterm exam

Session No.9 (4/5/02)
(1) Reading Assignment - Denture Repairs P.123
- 130 of AFP Vol. II
(2) Denture repairs:
A. Tooth Replacement
1. Reduce lingual area of acrylic.
2. Remove all acrylic from around retaining
pin if porcelain tooth.
3. If plastic tooth remove all of tooth from
facial surface to ajoining pink acrylic
(Do not remove any pink acrylic, or very
little).
4. Inspect ridge lap of tooth for mold No. of
tooth (Porcelain only).

Session No.10 (4/12/02)
(1) Reading Assignment - Denture Repairs P.123
- 130 of AFP Vol. II
(2) Fractured denture repairs:
A. Midline fractures.
1. Caused by poor denture fit or occlusal
problems.
2. Do denture repair, then reline the denture
if poor fit or occlusal problems are the
cause of the breakage.
3. This type of fracture is most ofter seen on
a max denture against natural lower
teeth.
B. How to repair.
1. Assemble the parts.
a. Use old metal burs to hold parts
together.
b. Do not use wood sticks to hold parts
together. (Wood will expand when in
contact with moisture from the stone)
2. Pour casts.
a. Blockout undercuts in denture prior to
pouring casts.
3. Prepare denture for repair.
a. Make bevel in repair area.
b. Make rabbit joint.
c. Do not grind all the way through the
denture.
4. Prepare cast to receive acrylic.
a. Paint cast with one coat of tinfoil
substitute.
b. Soak cast in slurry water.
c. Apply acrylic.

Session No.11 (4/19/02)
(1) Relining complete dentures.

Session No.12-13 (4/28/02 / 5/3/02)
(1) Questions from students (written) on areas of dental technology that they would like more clarification/information on. * Lectures for 5/2, 5/9 will cover these specific topics requested by the students.

Session No.14 (5/10/02)
(1) Review for final exam.

Session NO.15 (5/17/02)
(1) Final exam.

 

Notes from your previous semester for review:

Notes Week No. 1-3:

(1) Know the two basic materials that teeth are made from & the advantages/disvantages of each.
(2) Know how to select teeth based on patient's age, sex, and facial profile.