Record bases provide support for recording jaw relations and arranging teeth. They are made of materials like acrylic resin or metal and must be rigid, accurately adapted to casts, and comfortable. Occlusion rims are placed on record bases and are used to establish vertical dimension and make interocclusal records. They are constructed of baseplate wax and should be the proper dimensions with smooth contours. Together, record bases and occlusion rims are used to arrange teeth and make jaw relation records.
2. Learning Objectives
1. Define a record base and list the
materials used to make a record base.
2. Explain the technique of construction of
autopolymerizing acrylic resin record
base.
3. Define an occlusion rim and list the
uses of occlusion rims.
4. Explain the technique of making
occlusion rims.
3. Patient Visit #3
Visit 3
Clinical
procedure
Lab.
procedure
Jaw relations Face bow record
Transferring Jaw
Relations to the
Articulator
Anterior teeth
Arrangement
Horizontal
relations
Posterior teeth
Arrangement
Waxing & carving
Teeth arrangement
Vertical
relations
Orientation
relations Teeth selection
4. Record base: an interim
denture base used to support
the record rim material for
recording maxillomandibular
records.
Also called denture base
5. Requirements of record bases:
1. It should be rigid,
2. Accurately adapted to the
casts,
3. Fully cover the entire
supporting tissues of the arches,
4. Esthetic and
5. Comfortable to the patient.
6. Materials used to make record
bases:
1. Temporary record bases: They
are discarded and replaced by
denture base material, once their
role in establishing jaw relation,
teeth arrangement and try-in is
complete.
7. Materials used to make record
bases:
2. Permanent record bases: They
are not discarded and become
part of the actual base of the
finished complete denture.
8. Materials used to make record
bases:
Types of temporary record bases:
Shellac base plate
Reinforced shellac base plate
Chemically cured acrylic resin
Visible Light Cured (VLC) acrylic
resin
9. Materials used to make record
bases:
Types of permanent record bases:
Heat cured acrylic resin
Metal (Au, co-cr, Ti)
11. Clinical Context of Lab Exercise
Record Bases are fabricated on the
Master Casts following the 2nd
Clinical
Appointment (Final Impression
Appointment) and
Are used during the 3rd
and 4th
clinical
appointments for:
Maxillomandibular relation records
Arrangement of teeth for the wax trial
denture
23. Record Base Polymerization
Process acrylic resin in pressure pot
20 psi pressure
45 degrees C water
10 to 15 minutes
In absence of a pressure pot, place casts
under an over-turned rubber mixing bowl
24. Record base removal
Gently pry the record bases from the
master cast
Soak the polymerized record
base and casts in hot water to
soften the block-out wax
25. Remove wax which may prevent seating of record base from
tissue surface
Gently remove all block-out wax
from master cast without
damaging surface
28. Completed Record Bases Checklist
Palate should be consistent 2mm thick and well adapted to
tissue surface
Roughened ridge areas
Thin areas labial to ridge
Retromolar pad area covered
29. Completed Record Bases Checklist
No porosity or voids on tissue surface
Flanges smooth and rounded
Tissue surface well adapted
30. Completed Record Bases Checklist
No excess flash (acrylic) on land area of master casts
Flanges smooth and rounded
31. Record Bases & Occlusion Rims
Maxillary Occlusion Rim
Mandibular Occlusion Rim
Occlusion rims
32. Occlusion Rim: Occluding
surfaces fabricated on record bases
for the purpose of making
maxillomandibular relation records
and arranging teeth.
also called record rim
33. The record base and occlusion rims
are necessary for:
(1) establishing facial contours,
(2) help in tooth selection,
(3) establishing and maintaining the
vertical dimension of occlusion,
(4) making interocclusal records,
34. (5) the arrangement of the
denture teeth,
(6) a waxed-up mold for the
external surface of the complete
denture.
37. Mark the casts indicating midline, crest of the
ridge, and the midpoint of the retromolar pad.
These landmarks will be used to check teeth
arrangement.
maxilla mandible
Incisive
papilla
midline
Anterior
land area
Ridge
crest
Retromolar
pad
38. Lines indicating
the crest of the
ridge
Midpoint of
retromolar pad
Mark on land
indicating the
midpoint of the
retromolar pad
Land
39. Instruments and Materials
a) Baseplate wax
b) Wax knife & scale
c) Occlusal plane former (hot
plate)
d) Master casts with denture
bases
41. 22 mm height from labial frenum,
12 mm height in the tuberosity from the
record base
8-10 mm width posteriorly
6-8 mm width anteriorly
Maxillary occlusion rim
42. Mandibular occlusion rim
18 mm height from labial frenum, mid-
point or 2/3rds of retromolar pad
posteriorly,
8-10 mm width posteriorly
6-8 mm width anteriorly
43. a) Place maxillary record base
on the cast.
b) Heat a sheet of baseplate
wax in the bunsen burner
until the wax is soft.
c) Roll the wax into long tube.
d) Starting at the tuberosity,
press the roll of wax against
the crest of the ridge.
e) Seal the wax to the record
base with a wax knife.
Procedure
44. f) Heat the occlusal plane
former in a flame and
carefully form the occlusal
aspect of the rim.
g) Form the buccal and
labial contours with the
wax knife.
46. Maxillary wax rim check list
a) The occlusal portion of
the rim should have
the following thickness
1) Posterior region - 8-
10 mm
2) Anterior region - 6-
8 mm
b) The plane of the rim
should be parallel to
the plane of occlusion
AnteriorAnterior
regionregion
PosteriorPosterior
regionregion
47. Maxillary Wax Rim Check List
c) The labial and
palatal surfaces
must be smooth
and free of voids
d) The curvature of
the anterior portion
must simulate the
curvature of the
edentulous arch
48. The mandibular wax
rim is fabricated in a
similar manner.
However, the rim
should be centered
over the crest of the
ridge.
Lingual contours must be
concave and not impinge
on the tongue space