Complete Overdentures

Question 1

What is an overdenture?

Answer 1

One which gains its support partly or wholly from the roots of retained, decoronated (or crown modified) teeth

Question 2

Advantages of retaining roots?

Answer 2

• Retained root preserves the associated alveolar bone
• Root face gives extra support = allows tissues to support greater occlusal loads and protects the soft tissues from mechanical trauma
• Extra retention can be gained via attachments - CEKA and magnetic attachments
• Psychological benefit = knowing that remaining teeth will not be lost gives some pts reassurance
• Retained proprioception and tactile discrimination

Question 3

Disadvantages of retaining roots?

Answer 3

More expensive - primarily in doing RCT and denture reinforcement or/and extra retention is sometimes needed
Failure can occur due to caries - retained roots susceptible to caries under the denture as uncleansible
Takes longer - RCT and caries prophylaxis are prolonged

Question 4

When are overdentures specially indicated?

Answer 4

When alveolar bone resorption will be significant
When repeated alterations to dentures might be undesirable and extractions are contraindicated (elderly - issues with transport and may heal slowly)
When increases in face height are to be produced in cases of tooth wear or hypodontia
That adaptation might be poor and extra retention is desirable

Question 5

Which teeth are good for overdentures?

Answer 5

Root :

• Simple root canal shape - endodontics
• Adequate root size
• Sufficient support

Tooth site - near canine region
Bone - no buccal undercuts

Question 6

What tooth arrangement is good for dentures?

Answer 6

Site - bilateral tripod of support, opposed if possible

Proximity - not in contact

Question 7

Types of overdenture?

Answer 7

• Immediate - analogous to the immediate complete
• Transitional (temporary) - by addition to a partial denture. Generally provided to assess tolerance, caries rate, outcome
• Permanent/replacement - a permanent overdenture which often has extra strenghtheners or retaining mechanism

Question 8

Features of type 1 immediate dentures?

Answer 8

Extractions necessary
Canines are to be retained
Molar and premolar to be extracted due to difficult endodontics and caries

Question 9

Features of type 2 immediate dentures?

Answer 9

No extractions

Upper right incisors and canine are to be preserved as denture abutments

Question 10

Features of transitional (temporary) overdenture?

Answer 10

Provided by extension of a current partial denture or after making a temporary partial denture
Its placement is carried out in hope - either fulfilled later when a permanent overdenture is placed or frustrated when a complete conventional denture is placed

Question 11

Associated problems with over dentures?

Answer 11

Endodontics - overdentures on root filled teeth are more successful
Functional contact 
Abutment form
Additional retention
Aftercare