Overdentures Flashcards
Definition
An overdenture is one which gains its
support partly or wholly from the
roots of retained, decoronated (or
crown modified) teeth
Advantages of retaining roots
- The retained root preserves the associated
alveolar bone - The root face gives extra support
- Extra retention can be gained via attachments
- Psychological benefit
- Retained proprioception and tactile discrimination
- The retained root preserves associated alveolar bone
Enhances stability
Prevents resorption
- The root face gives extra support
Allows the tissues to support greater occlusal loads and protects the soft tissues against the effects of mechanical trauma
- Extra retention can be gained via attachments
CEKA and magnetic attachments provide positive retention
- Knowing that the remaining teeth will not be lost gives some patients reassurance
The psychological benefits of retaining teeth should not be underestimated
- Retained proprioception and tactile discrimination
Claimed
Certainly feedback from the periodontal ligament allows
better discrimination of particle sizes and textures
Disadvantages of retaining roots
- More expensive
- Failure can occur due to caries
- Takes longer
- More expensive
Primarily in carrying out root canal
treatment, but also because denture reinforcement
and/or extra retention is sometimes needed
- Failure can occur due to caries
The
retained roots are susceptible to caries in the protected environment under a
denture
- Takes longer
Although review is less expensive (fewer alterations needed), preparatory work (RCT) and aftercare (primarily caries prophylaxis) are more prolonged
Cases in which overdenture treatment specially indicated
- When it is thought that alveolar resorption will be
significant. - When repeated alterations to dentures might be
undesirable and extractions are contraindicated - When increases in face height are to be produced in
cases of tooth wear or hypodontia - When it is thought that adaptation might be poor and
extra retention is desirable
- When it is thought that alveolar resorption will be
significant
(Unopposed mandibular anterior teeth can predispose to maxillary atrophy)
- When repeated alterations to dentures might be
undesirable and extractions are contraindicated
(The elderly often
have problems with
transport and may
heal slowly)
Individual tooth selection
• Root -simple root canal shape: endodontics -adequate root size -sufficient support • Tooth site -near canine region • Bone -no buccal undercuts
Tooth arrangement
Site -bilateral tripod of support -opposed if possible Proximity -not in contact
Types of overdenture
1. Immediate – analogous to the immediate complete 2. Transitional (temporary) – by addition to a partial denture. Generally provided to assess tolerance, caries rate, and outcome 3. Permanent/ Replacement – a permanent overdenture which often has extra strengtheners or retaining mechanisms
- Immediate – type I, extractions necessary
Canines are to be retained. Molar and premolar are to be extracted – due to difficult endodontics and caries respectively
- Immediate - type II, no extractions
URincisors and canine are to be
preserved as denture abutments
- Transitional (temporary)
overdenture
Not quite analogous to the transitional partial
denture. Provided by extension of a current partial
denture or after making a temporary PD
Placement always carried out in
hope – which is either fulfilled later when permanent overdenture is placed, or frustrated
when a complete conventional denture is place
Associated problems
- Endodontics
- Functional contact
- Abutment form
- Additional retention
- Aftercare
- Endodontics
Overdentures on root filled teeth are more
successful that on non-root filled teeth
- Functional contact
If abutments on
model are longer
than the prepared
abutments
