1.
RECORD BASES AND
OCCLUSION RIMS

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)

10.
Technique of construction of
autopolymerizing acrylic resin
record base
(sprinkle‐on technique)

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

12.
Materials

13.
Block-out undercuts
 Block-out under cuts with
modelling wax.

14.
So that the record base can easily
be removed from the cast without
damaging the master cast.

15.
 Blocked out Master Casts
coated with separating media.

16.
Maxillary record base fabrication
 Sprinkle-on Technique of
resin addition

17.
Build up labial flange by alternating
polymer and monomer addition

18.
Sprinkle on a thin consistent
layer over the palate

19.
Reinforce the ridge crest to
prevent slumping

20.
Keep the surface moist with monomer to
prevent porosity

21.
Manipulate the cast to prevent slumping
Build up the flanges

22.
Reinforce the lingual portion of
the flange and ridge crest

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

26.
Areas requiring
modification on
unfinished record
bases
Land
Flash

27.
Trim excess acrylic- flash

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.

35.
MATERIALS USED FOR MAKING
OCCLUSION RIMS
1. Base plate wax

36.
Anterior
land area
Midline
Incisive
papilla
Guidelines drawn on the master
casts

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

40.
Dimensions of occlusion rims

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.

45.
Use hot plate

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

49.
Mandibular Occlusion Rim
Adjustment
 Centered
over the
ridge to
maximize
stability

50.
Mandibular Occlusion Rim
Adjustment
 Posteriorly, the
occlusion rim
intersects 1/2 -
2/3 up the
retromolar pad