Figure 8-37.adapting a denture tooth to the edentulous
template off the cast for final trimming with scissors.
Cut out the section needed for the provisional
restoration plus one or two uninvolved teeth anterior
and posterior to it as shown in figure 8-38. When you
are finished, clean and disinfect the template; and
place it and any of the unused arch sections back on the
cast so they won't distort. Often, subsequent
restorations are made for the same patient, and the
unused arch sections are kept in case they will be
needed at a later date.
SIMPLE ACRYLIC REPAIRS
Occasionally, you will be required to perform
minor repairs on complete and removable partial
dentures. These repairs may include fractured
dentures, or replacing fractured, missing or loose teeth.
These repairs may be caused by changes in the oral
tissues, careless handling, etc. The dentist will decided
if any impression of the patient's mouth is needed for
the repair, and will tell you what needs to be done to
complete the repair. Since every repair is a little
different, these next procedures describe some, but not
all, of the possible repair solutions. If you need
assistance, refer your questions to the dentist or
DENTURE BASE REPAIRS
Figure 8-39 shows a simple denture base fracture.
The repair procedures will include aligning the
fractured parts, pouring a plaster cast (matrix),
Figure 8-38.Trimming away excess material with scissors.
Figure 8-39.Simple denture base fracture.
widening the fracture line and making retentive
grooves, applying self-curing acrylic resin, adjusting,
and polishing. When the pieces of the denture base
cannot fit against one another in a precise relationship,
or one or more fragments have been lost, this type of a
fracture is classified as complex. Since complex
fractures should be repaired by prosthetic technicians,
they will not be covered in this chapter. To repair a
simple denture base fracture, perform the following
steps (A-H) shown in figure 8-40:
1. Align the fractured denture parts and apply
sticky wax over the fracture line on the external surfaces
of the denture.
2. Stabilize the parts by positioning denture burs
with sticky wax as shown in step A.
3. Block out all undercuts on the internal surface
that will be exposed to the plaster with a wet pumice mix
or block out wax (step B). Do not block out undercuts
along the fracture line. Blocking out the undercuts
enable you to remove the plaster cast after it sets.
4. Prepare a plaster mix.
5. Slowly pour the plaster into the internal surface
of the denture. The plaster cast should cover the fracture
line, but not the entire denture. This procedure is
accomplished by holding the denture in you hand and
gently resting it against the vibrator.
6. Place the denture in an upright position (step C)
and allow the plaster to cure.
7. Once the plaster is set, gently remove it from the
8. Remove the denture burs and all traces of the
sticky wax and pumice.
9. With a new denture bur, widen the fracture lines
(step D) on the denture and place retentive grooves
along the fracture line.
10. Paint two thin, even coats of tinfoil substitute on
the cast (step E).