16. Tooth supported overdentures Flashcards
What is a tooth supported overdenture?
-Removeable dental prosthesis
-partially supported by 1 or more remaining natural teeth/roots and/or implants
-
Advantages of a tooth supported overdenture? (5)
- Preservation of alveolar bone.
- Improvement of support, retention and stability.
- Increased masticatory efficiency.
- Preservation of proprioception.
- Comfort
Tooth supported overdenture indications? (4)
• Have teeth that are unreliable for RPDs but are in good condition for an overdenture.
• Patients that will probably have bad adaptation to
a CD.
• Extreme dental wear.
• Patient can’t pay for an implant treatment
Tooth supported overdenture contraindications? (4)
• Unreliable teeth. - Periodontal decease. - Endodontic treatment. • Bad teeth location. • Small interocclusal space.
Tooth supported overdenture: What is the periodontal condition required for abutment teeth? (4)
- probing of less than 4mm
- discard teeth of type II and III mobility
- adequate crown to root ratio
- atleast 50% bone attachment
Tooth supported overdenture: What is the endodontic condition required for abutment teeth?
-ALWAYS preform endodontic treatemnt when placing attachments
Tooth supported overdenture: When do we do endodontic retreatment? (2)
◦ Previous one is not adequate.
◦ Radiolucent periapical area.
Tooth supported overdenture:
tooth number?
more teeth = better
Tooth supported overdenture: tooth placement? (3)
- At both sides and symmetrically placed: best
situation.
◦ Teeth are not overloaded.
◦ Less fractures.
Tooth supported overdenture: Ideal abutment teeth?
- Two anterior and two posterior teeth
- Canines are the best
Tooth supported overdenture: What happens if abutment teeth are placed next to eachother?
Hindered hygiene
Tooth supported overdenture: Antagonist natural dentition?
tends to load more
abutment teeth
Tooth supported overdenture: combination syndrome? (4)
◦ Upper edentulous arch.
◦ Lower front teeth.
◦ Increased upper anterior ridge resorption.
◦ Preserve upper anterior roots as much as possible.
Tooth supported overdenture: choice of root shape and support? (2)
- Multi-rooted teeth: greatest support.
- Conical roots: least support.
Tooth supported overdenture: root shape and hygiene?
Noticeable root concavities hinder hygiene and produce periodontal problems
Tooth supported overdenture: What are the types of attachments? (2)
Axial
Bar
Tooth supported overdenture: What are the types of axial attachments? (4)
◦ Coping.
◦ Ball.
◦ Locator.
◦ Magnetic attachments.
Tooth supported overdenture: What are the types of bar attachments?
◦ Ackerman bar.
◦ Dolder bar.
◦ Hader bar.
◦ Mechanized parallel wall bar.
Tooth supported overdenture: Where should bar attachments be?
Over the edentulous ridge
Tooth supported overdenture: Bar attachments and no rotation? (3)
- ex. 4 abutment teeth
- U and Parallel wall bar shapes
Tooth supported overdenture: Bar attachements and rotations? (4)
-ex. 2 abutment teeth
-shapes:
◦ Cylindrical bars.
◦ Ovoid bars.
◦ Parallel to the transverse
horizontal axis.
Tooth supported overdenture:
Endodontic treatment procedure? (4)
- START WITH Gates n*1 and Peeso burs
- Conical drills
- min 4mm gutta percha
- from smaller diameter to bigger
Tooth supported overdenture: procedure for preparation?
- endodontic
2. coronal portion
Tooth supported overdenture: Procedure for coronal portion prep? (3)
- Leave 2-3 mm of tooth over the gingiva. (smaller lever effect over the tooth)
◦ The coping should embrace the root (ferrule effect). - Chamfer finish line all around the tooth (0.3-0.5 mm)
- Build boxes if necessary.
- Round edges.
Tooth supported overdenture:
Height of abutment teeth? (2)
- Low profile to decrease the lever effect
* > 2-3 mm when doing telescopic crowns.
Tooth supported overdenture: What is the furrule effect? (2)
• If placing any kind of attachment, build a coping.
- Provides metallic support to the overdenture.
Tooth supported overdenture: What do we do if the tooth is not high enough?
Place just a coping
Tooth supported overdenture: both the post and coping must have…?
an adequate path of insertion
An overdenture is weakend by…? (2)
attachments
-use a built in frame work for reinforcement
Tooth supported overdenture: What is the importance of placing copings?
Preventing root fractures
Tooth supported overdenture: What hinders hygiene?
Attachments hinder hygiene more than plain copings
Tooth supported overdenture: Post design? fractures? (4)
- Some are placed directly into the root, without laboratory coping.
◦ Higher risk of root fracture.
Tooth supported overdenture: Post material? (2)
- Should be made of a flexible alloy.
◦ Type III gold alloys
Tooth supported overdenture: which posts are more retentive? (2)
- Parallel walls are more retentive than conical ones
- Conical posts adapt better to the root
Tooth supported overdenture: What posts do we never use?
threaded - higher fracture risk
Tooth supported overdenture: Post width?
Not to be greater than 1/3 of the diameter of the root
Tooth supported overdenture: If there are only two anterior teeth?
One then allows rotation
Tooth supported overdenture: IF there are anterior and posterior abutments?
- Attachments allow vertical resilience
Tooth supported overdenture: What must we do for attachment and prosthetic space? (3)
- Measure vertical prosthetic space.
- There must be room for the attachment.
- Check that the diameter of the root also provides
room for the attachment.
Tooth supported overdenture: Requirements for bar attachments? (5)
- Splint abutment teeth.
- Occupy more space.
- Metallic framework.
- More difficult hygiene.
- Minimum space between bar and gingiva of 2 mm.
Tooth supported overdenture: What happens if you use putty and light body silicone?
Soft tissues would be copied under pressure
Tooth supported overdenture: Procedure for taking impressions? (3)
- Castable post.
- Light-body silicone for the coping.
- Monophase silicone for the soft tissue.
Tooth supported overdenture:
Alternative impression taking procedure? (3)
- Take putty and light body silicone impression.
- Finish and cement the attachments.
- Adapt them to the CD with acrylic resin.
