Overdenture Treatment Planning and Factors Affecting Teeth Selection
1.
2. Dr. Amal Fathy Kaddah
Professor of Prosthodontic,
Faculty of Oral &Dental Medicine, Cairo University
Dr. Mohammad Abbas
Dr. Khalil Ibrahim Sharif
3. Learning Objectives
Definitions
Types
Indications/contraindications
Advantages/disadvantages
Treatment plan
Factors affecting teeth selection and teeth
preparation for overdenture
Protocol – lab/clinic
4. Definitions
The overdenture is a
removable complete or
partial denture prosthesis
constructed over existing
teeth, root structure
and/or dental implants.
5. A removable dental prosthesis
that covers and rests on one
or more remaining natural
teeth, roots, and/or dental
implants.
The overdenture is also called
“overlay denture”, “overlay
prosthesis”, “superimposed
prosthesis”
An overdenture is
Partial overdenture
6. Maxillary alveolar ridge with the remaining
roots (canine, second premolar, and first
molar covered with metallic caps
Initial aspect after insertion of maxillary
overdenture >>>
Tooth supported complete
overdenture
10. 1. Preservation of the remaining teeth
A. Preservation of proprioceptive response
that Enhance neuromascular control,
occlusal awareness and biting force.
B. Increased patient acceptance and
psychological benefits.
Advantages of Overdentures
Tallgreen A
Acta Odontol Scand 24: 195-239, 1966.
11. Mechanoreceptors
Are sensory neurons or peripheral
afferents specialized to receive
tactile information are in the
epidermisz.
Within joint capsular tissues,
ligaments, tendons, muscle, and
skin.
Exist in abundance within the periodontal
ligaments and anterior part of the palate
12. Ligamentous mechanoreceptors
There are four types of mechanoreceptors
embedded in ligaments. As all these types of
mechanoreceptors are myelinated, they can
rapidly transmit sensory information to the central
nervous system.
• Type II and Type III mechanoreceptors in particular
are believed to be linked to one's sense
of proprioception
13. Proprioception
Periodontal mechanoreceptors are said to allow
a finer discrimination of food texture, tooth
contacts and levels of functional loading.
This neuromuscular coordination allows patient
to have better control and greater confident in
their ability to eat, drink and speak.
The bite force for natural dentition is 150-200
lb/in². Complete denture is 25 lb. and
overdenture is 75 Lb.
14. Proprioception
Periodontal proprioception plays a role in
Neuromuscular coordination,
jaw position perception and
Protection from accidental overloading
More masticatory efficiency was reported
in patients treated by overdentures when
compared to complete denture wearers.
15. c. Improved Crown to Root ratio (C/R)
Tooth height is reduced >> provide
enough space for the denture base
and artificial teeth without
interfering with the patient’s VDO
A clinical crown 1-2 mm above the
gingival margin
The favorable C/R diminishes the
lateral forces on the abutment and
decreases the tooth mobility
elicited by occlusal overloading.
16. 2- Preservation of residual ridge
•Improved occlusal stress distribution.
•Edentulous mouth Bone loss of 6.6mm in
7 years.
•Dentate mouth Bone loss of 0.8mm in 7
years.
Mandibular bone is affected four times
more than the maxillary bone.
Tallgreen A
Acta Odontol Scand 24: 195-239, 1966.
Advantages of Overdentures
22. Advantages of Overdentures
Enhance Support >>
a. Preservation of the alveolar bone
b. Presence of natural teeth leading to
less trauma to soft tissues
23. Advantages of Overdentures
Enhance Stability >> The denture
seats in an exact position, with minimal
or no lateral movements
Improved retention
More accurate jaw relation records
Occlusion can be easily perfected
Less soft tissue trauma
Increased biting force
24. Advantages of Overdentures
Enhance Stability >> The denture
seats in an exact position, with minimal
or no lateral movements
Improved retention >> enhance stability.
More accurate jaw relation records: as a
result of increased stability and retention of
the recording bases; J.R.Rs. are easily
obtained and verified.
25. Advantages of Overdentures
Enhance Stability >>
Occlusion can be easily perfected by
the accuracy of jaw relation records,
while the occlusal relationships are
maintained by the positive support from
the abutments.
26. Advantages of Overdentures
Enhance Stability >>
Less soft tissue trauma:
Perfect occlusion
jaw position perception, provided by the
proprioception of natural teeth,
Leads to a rapid development of a more
efficient masticatory function and Increased
biting force.
27. Advantages of Overdentures
Enhance Retention through the
use of attachments >>
The denture is chiefly retained
mechanically. Less soft tissue coverage is
needed when attachments are used
28. 4. Patient acceptance and
Psychological Benefits
5. Convertibility
6. Conventional dental procedures
Advantages of Overdentures
30. 2. Periodontal breakdown of the
abutment teeth (loss of
periodontal attachment).
– Gingivitis
– Periodontitis
– Hyperplasia
due to Covering of the gingival margins
Uncovered teeth are less
protected against caries
Disadvantages of Overdentures
31. • To account for the height of
the abutment, the coping, and
the attachment system
• Inadequate reduction of the
abutment teeth may increased
vertical dimension
Disadvantages of Overdentures
3. Requires a larger inter-arch space
32. Inter-arch Space
The determination of a case to be treated with
overdentures should be done with care, mounted
models are extremely beneficial in determining
whether there is adequate space for the
overdenture, attachments
or copings.
33. Disadvantages of Overdentures
An adequate space is required
between the highest point of the
abutment’s gingival margin and
the opposing occlusal plane. The
minimal required space ranges
between 8 – 13 mm
and depends on the type of abutment preparation
(e.g. short or long coping, with or without attachment,
the attachment type and its height, etc.).
35. 4. Bony undercuts:
A. Limitation of the
path of insertion
of O. D.
Disadvantages of Overdentures
36. B. Surgical alteration of the denture-bearing area.
C. Blocking out of the undercuts
D. Careful planning of the path of insertion
E. The use of resilient lining materials in the
undercut areas.
F. Trimming of the denture base.
38. 1. The remaining teeth cannot support
traditional fixed or removable partial denture
A. Insufficient number of teeth
B. Unfavorable location
C. Periodontally weak teeth
D. The reduction of the coronal portion of the tooth
improves the crown/root ratio and decreases the
teeth mobility.
Indications for Overdentures
39. 2. Preserve strategic tooth
Sometimes a remaining weak tooth
gained a special strategic importance
as in case of:
“Combination syndrome”
A weak lonely standing molar next to
an edentulous area.
40. 4. Compensation for
alveolar deficiency:
Angle’s class II and class III
Microdontia and partial anodontia
Maxillofacial restorations
Indications for Overdentures
3. Severe attrition
41. A patient with repaired cleft who was treated by upper partial
overdenture to compensate for arch size discrepancy
42. Contraindications for Overdentures
1. If any other prosthetic plan (fixed or removable) can give
superior results.
2. Poor oral hygiene (Patient who does not respond to oral
hygiene motivation)
3. Inadequate interarch distance.
4. Poor periodontal condition
Sever alveolar bone loss (less than 5-6 mm)
Inadequate zone of attached gingiva
5. Non-restorable abutment teeth
Unpredictable root canal treatment
Severely mutilated teeth
44. Detailed logical sequence of
procedures to restore the
patient’s dentition to good health,
with optimal function and
appearance.
Treatment planning for
overdenture cases
46. Diagnostic phase
Medical and dental history.
Photographs (Extra-oral and intra-oral).
Panoramic and periapical radiographs of the remaining teeth.
Clinical examination and periodontal charting.
Study casts mounted in centric relation at the proposed
vertical dimension of occlusion.
Diagnostic Wax-up and trial setting-up of teeth.
Study casts mounted in centric relation at properly estimated
vertical dimension (VD) is critical in planning for overdentures,
evaluation of the interarch space
47. Abutment selection
1. Periodontal condition
2. Endodontic evaluation
3. Number, Position and distribution of abutments
teeth
4. The space between abutments
5. Decay or previous restorations.
6. Teeth present in the opposing arch
48. – Periodontal condition: About 6 mm of
bone support with minimal mobility and
2-3 mm of attached gingiva around the
tooth.
– Endodontic evaluation: single rooted
teeth are usually preferred than multi-
rooted teeth.
Abutment selection
49. Number, Position and distribution of
abutments teeth
– Widely separated, symmetrically distributed
abutments is the ideal situation for
overdenture support.
– More abutments can be retained, two
abutments in the canine region are
satisfactory
Abutment selection
50. Number & Position of abutments
At least one tooth per quadrant.
Retained teeth should preferable
not be adjacent ones.
There should be several
millimeters of space between the
reduced tooth forms.
Canines and premolars are the
best overdenture abutments to
reduce adverse forces at this site.
51. Periodontal and Mobility Status
Bone support, pocket depth, width of attached
gingiva, mobility, furcation involvement, & root
morphology.
Minimal mobility
At least 6mm of bone support
Attached gingiva around the abutments
Good oral hygiene
Proper emergence profile to support the
marginal gingiva.
53. Endodontic Potential and prosthetic status
• Single rooted teeth are easer to treat.
• Pulpal recession
• The use of restorative materials and
sealants
• Prior RCT already done.
• Potential for RCT.
54. Restorative Condition
Caries.
Previous restorations.
Crown lengthening indicated.
Teeth present in the opposing arch
select overdenture abutments, if possible,
opposite to remaining natural teeth.
55. Provisional restorations
It is unacceptable to leave a patient
without a temporary restoration
during any lengthy phase of denture
construction.
56. Detailed logical sequence of
procedures to restore the
patient’s dentition to good health,
with optimal function and
appearance.
Treatment planning for
overdenture cases
57. Planning of the next stages depends
on the patient situation where
1. The patient is already wearing a partial denture.
2. The patient has no partial denture
Immediate
Transitional
Definitive (Remote)
58. Immediate Overdenture
I.O.D. is constructed prior to
the preparation of abutment
teeth and inserted after the
preparation.
When the processed denture
is fitted, it is relined with cold
cured acrylic in the areas
around the abutment teeth to
make it fit as well as
possible.
59. Transitional Overdenture
Obtaining by Converting an
already existing RPD to an O. D.
The patient is sequentially
modified by addition of artificial
teeth
62. Tooth-supported Overdentures
Tooth modification of
vital abutments
Tooth modification
with Endo therapy
Non
coping
Coping
Dome
shaped
Long
coping
With cast
coping and
attachments
With post
and coping
With
amalgam
plug
Simple
tooth
reduction Thimble
tooth
reduction
Short
coping
Telescopic
Overdenture
Stud
Bar
Magnet
63. Tooth-supported over-dentures
I. Tooth modification of vital abutments
1. Simple tooth modification without cast coping
2. Tooth modification with cast coping:
a. Thimble Shaped abutments (Long Coping)
b. Dome- shaped abutments (Short Coping)
c. Telescopic Overdenture
II. Tooth modification with Endodontic therapy and
amalgam plug
III. Tooth modification with Endodontic therapy with post
and coping
IV. Tooth modification with Endodontic therapy with cast
coping and attachments
64. 1- Simple tooth modification of vital abutments
• The abutments are reshaped to just
eliminate undercuts,
• The patient must have good oral
hygiene and low caries index.
• Wide inter-occlusal distance is
essential,
• Microdontia, or partial Anodontia
65. This method has the advantage of:
1. Being reversible.
2. It is used as a temporary restoration to try the
acceptance of the patient to the overdenture
option or during other treatment steps.
3. It may be used as a final restoration
69. Abutments are considerably
prepared to provide space for a
thin metal or zirconium coping
called “primary coping” or
“thimble crown” that may be
covered with another coping,
attached to the denture base,
called secondary coping.
2- Thimble-Shaped abutments (Long Coping)
70. This technique requires
inter-arch space enough to
accommodate the copings
and the denture base with
the artificial teeth, without
over shortening of the
abutments.
2- Thimble-Shaped abutments (Long Coping)
74. 4. Telescopic overdenture: (Tooth reduction with long
cast coping of vital or Endodontically treated
abutments)
A.Conical shaped copings with rounded top
B.Parallel surfaces copings with flat top
75. Gold or metallic cast Copings and telescopic crowns
are a method of improving overdenture retention and /or
support and bracing according to their types:
1. Milled crowns for larger areas and parallel
surfaces. (support and bracing)
2. Conical crowns (semi-parallel wall) with a
friction adaptation at the marginal area of the
abutment
Friction retention is more commonly used in exclusively
tooth-supported overdentures that are not supported by
soft tissue.
76. Full extension of flanges is not
critical. the abutments are designed
to provide support and bracing
telescopic overdenture: the copings
have milled parallel walls and the
denture has secondary copings.
Retention is gained from friction
due to the parallel walls of the
primary copings and the precise fit
of the secondary copings
82. Normal clinical crown
Normal inter-arch distance
With no or little loss of vertical dimension.
As the abutments must be extremely
reduced to create enough space for the
overdenture, endodontic treatment is
necessary.
83. Abutments are reduced to be 1-
2 mm above the gingival margin
Part of the root canal filling is
removed;
Small cavity is prepared and
filled with direct restorative
material as amalgam or
composite resin.
84. If this will be the final abutment form, the patient
must have good oral hygiene and low caries index.
The root face is contoured into dome shape
and polished.
The buccal surface is beveled 30°, the
lingual surface 15°, and the proximal
surfaces are modified to remove the
undercuts
This form prevents lingual bulging of the
denture base at the abutment site and
allows an esthetic setting of artificial
teeth.
85. 6- Endodontic therapy with post and cast
coping
Thin cast metal copings to protect them from
caries, the copings are retained by custom
made posts cemented in their root canals
86. 7- Endodontic therapy with cast coping
and attachments
Requires an extra space over the dome shaped
abutment which varies according to the attachment
shape and height., Not alter the crown/root ratio
87. 7- Endodontic therapy with short cast
coping and attachments
Good periodontal condition of the abutments is
essential to withstand the added stress that
attachments bring to the abutments
88. 8- Endodontic therapy with ready made
post with attachment
The post system has special drills that
prepare the root canal to a shape suitable
to receive the post.
The post usually carries the male part of
the attachment while the female part is
picked up in the fitting surface of the
denture after cementation of the post.
As the dentin of the root face is exposed,
this technique is not regularly used to
retain definitive overdentures
89. Treatment Planning
Patient Selection
– Medical History.
– Oral Hygiene.
– Compliance.
– Motivation.
Abutment selection.
– Position.
– Number of abutments
– Periodontal evaluation.
– Endodontic evaluation.
– Decay or previous restorations.
Inter-arch space.
90. Selection of Overdenture
Attachments
Available interarch space
Cost
Alignment of the roots
Maintenance issue
Clinical experience and
personal preference
92. 1. Crown root ratio.
2. Type of coping.
3. Vertical space available.
4. Number of teeth present.
5. Amount of tooth support.
6. Location of abutments.
Attachment selection:
it based on:
93. 7. Location of the strongest abutments.
8. Whether the overdenture is to be a tooth-
supported or tooth-tissue supported.
9. Type of the opposing dentition whether
complete denture, overdenture, fixed
appliances or natural dentition.
10.The maintenance problems and of least
importance the cost.
Attachment selection:
it based on:
94. Clinical Procedures
I-Abutment preparation:
- Crown reduction and contouring with or
without endodontic treatment
- Periodontal treatment.
II-Primary impression:
Alginate impression in stock tray.
III- Special trays constructed on primary cast.
95. Preparing the Abutments
1. Maximum Reduction of the Coronal
Portion
2. Crown-root ratio
3. No interference with artificial tooth
placement
4. Restoration and polishing
Crown reduction
96. Abutments are reduced to be
1-2 mm above the gingival
margin
Preparing the Abutments
Cylindrical with flat and round ends, flame shaped,
and wheel shaped stones
98. Preparing the Abutments
The root face is contoured into dome
shape and polished. The buccal
surface is beveled 30°, the lingual
surface 15°, and the proximal surfaces
are modified to remove the undercuts.
99. This form prevents lingual bulging of the
denture base at the abutment site and
allows an esthetic setting of artificial
teeth.
105. Clinical Procedures
Secondary impression is made using rubber
base, pour stone casts
Wax patterns for copings
Casting into metal
Copings are cemented on prepared
abutments
Another Impressions are made to obtain
casts for the coping-covered abutments.
106. Another Impressions are made to obtain casts
for the coping covered abutments
Upper special tray which is
spaced for an alginate
impression technique
107. If precision attachments are
used, a special tray is used
with either impression paste
or elastomers depending on
the presence of undercuts.
The tray has a window over
each of the abutments,
Another Impressions are made to obtain casts
for the coping covered abutments
this ensures any excess material flows out, without
displacing any of the tissues
108. Polyvinyl siloxane or poly ether is
recommended when copings or
attachments are planned for. These
impression materials can be accurately
poured twice to obtain two duplicate
models, one of them is used for the
fabrication of the metal work, and the
other is used for the denture
processing.
109. Zinc oxide impression paste may be
used in cases with minimal
undercuts as in case of abutments
with restorative plugs or short
copings that were previously
fabricated from another impression
and cemented before the final
impression for the denture
110. Clinical Procedures
IV- Jaw Relation Records:
Mounting of upper cast on semi ad. art.
by face-bow record >> mounting of
lower cast by centric occluding relation
Setting up of teeth.
111. Construction of copings or attachments
To avoid overdenture’s metal
frameworks or attachments that may
interfere with setting up of teeth or
leading to unacceptable bulky base a
putty index is made for the accepted
waxed denture.
112. Clinical Procedures
Fitting surface of the trial denture should be
relieved over the abutments for proper denture
settling
Check for stability
Check vertical dimension
Check occlusion.
V- Try-in:
115. “Passive” Contact
Abutment contacts denture
in function only
Fitting surface of the trial
denture should be relieved
over the abutments for
proper denture settling,
avoid pressure on the
gingival margin of the
abutments
RESTING
FUNCTION
117. Post insertion care
A series of post-insertion
appointments must be planned when
plaque control and denture hygiene is
stressed. Plaque control instruction
plays an important role in the initial
therapy.
118. 1. Remove the denture when sleeping.
2. Kept it in tap water or denture cleanser
3. Rinse the mouth, and clean the dentures after every
meal.
4. Brush teeth with fluoride toothpaste at least twice
a day.
5. Put one drop of high concentration neutral fluoride
gel (5,000 ppm) in the depression of the denture
corresponding to the abutment after brushing once
a day, and then seat the denture in the mouth.
6. To get the maximum benefit of the fluoride
treatment, the patient should not eat or drink
anything for at least half an hour.
