3. Learning outcomes
1. List the types of denture
fractures.
2. Explain the procedure for denture
repair.
3. Explain the procedure for denture
tooth replacement.
4. Types of Denture Fracture
Midline fractures
Fracture or chipping of a
portion of the denture
Multiple fractures (more
than two pieces)
Cracks in the denture
Fracture or dislodgement
of one or more teeth
5. The most common
fracture of a
complete denture
occurs in the
midline of the
maxillary complete
denture.
Causes of denture fracture
6. This occurs because
as a ridges resorb,
the palate does not
resorb. This results in
the dentures
contacting only in the
palatal area and not
contacting the ridge
area.
7. Therefore all the
pressure is
transferred to the
middle of the palate.
The stresses
increase as the
ridges resorb,
increasing the
likelihood that the
denture will fracture
in the mid-palate as it
8. Other causes of denture
fracture
1. Deep labial frenal notch
2. Absence of labial flange
3. Incomplete polymerization of acrylic
resin
4. Previous repair
5. Maxillary posterior teeth placed
buccally
6. V shaped palatal arch
9.
10.
11.
12. 7. Accidental dropping of
the denture
8. Faulty denture design
resulting in areas of
inadequate thickness
9. High occlusal loads
10. Single denture
15. When the dentures can not be repaired
When the broken pieces cannot be
joined accurately
When the dentures need to be replaced
anyway due to poor fit or occlusal wear
or any other reason
16. Types Of materials used in
repairs
1.Chemical-Cured acrylic
2.Visible Light Cured (VLC) acrylic
19. • Broken parts are
assembled &
fixed together
with sticky wax
on the polished
surface.
• Assembled
parts may be
strengthened
with burs or
plastic sticks.
20. • Any undercut on
the fitting surface is
blocked out with wax
or clay.
• The fitting surface
is painted with
petroleum jelly.
21. • Stone plaster is poured into
the fitting surface. After stone
has set, the denture is
removed from the cast and
cleaned from any traces of
sticky wax.
• Fractured edges are
widened along the fracture line
and beveled towards the
polished surface to increase
bonding surface area.
22. • The cast is painted with
separating medium and
the denture is secured to
the cast with rubber
bands.
• Self cure acrylic resin is
applied to the modified
fracture area until the
area is overfilled.
•Cure the denture in the
pressure pot.
38. Here a fractured flange is shown, but the process is
the same for any fracture of a denture base. A midline
fracture of a maxillary or mandibular denture would
follow the same steps.
Fracture Line
39. First, hold the pieces of the fractured appliance
together to evaluate their “fit”. If the segments
don’t relate very accurately, we have a problem
at this stage.
40. While CAREFULLY holding the segments
together, have someone flow sticky wax at
the fracture line to temporarily hold the
segments together.
41. These images show the segments held together with
sticky wax. Note that the inner aspect of the denture
has no wax in it at all. The fracture is visible as a fine
line on the inner surface of the denture. We will now
make an index which will orient the segments during
the remainder of the repair process.
42. Once the
segments of the
denture have been
related, we make
an index using fast
setting plaster. The
plaster is first
carefully placed in
the denture in the
area of the fracture
so that we have no
voids in the index
in this area. The
denture is then
inverted on a small
base of plaster to
complete the
index.
43. The denture is inverted on the
base of plaster and the
peripheries smoothed. After
the plaster sets we have an
index to relate the segments
for the repair procedure itself.
44. The denture is then lifted off the
index and the edges of the broken
segments are beveled toward the
outer surface. This will provide
fresh acrylic to allow a better repair
as well as provide more surface
area for the repair acrylic to bond
to.
45. Here we have two views of the beveled surfaces
ready for the addition of repair acrylic. Note the
bevel is toward the outer surface of the denture.
This leaves the inner surface minimally disturbed.
We also have a large surface area for the new
repair acrylic to form a bond with.
46. Repair acrylic is then placed
along the fracture line by
dipping the brush in liquid
and picking up a small
increment of powder. The
increments of repair acrylic
are placed in the defect and
the denture placed in warm
water.
47. The completed repair is removed from
the index and the area smoothed with an
acrylic bur.
48. After the repaired area has been shaped and
smoothed with a bur, the denture is polished
with pumice.
51. After block out of the undercuts in the denture
a cast is poured into the denture itself. Care is
taken to create a land area around the
denture especially in the posterior area.
52. The denture is removed from the cast. The posterior
area corresponding to the palatal seal is a good
reproduction of the inner surface of the denture with
the impression wax. Remember, the green stick had
been molded in the patient’s mouth and the
retention was seen to have been increased.
In the lab exercise, you will do a repair of a fracture of the mandibular complete denture. This is mainly because It is easier to break the mandibular complete denture into two pieces than it is to break the maxillary complete denture into two pieces.