Overdentures Flashcards
Overdenture definition
Prosthesis that derives support from one or more abutment teeth (implant) by completely enclosing them beneath its impression surface
Reasons for tooth supported overdentures?
Maintenance of alveolar bone
Why is it important to maintain alveolar ridge height?
Increased resistance to antero-posterior, lateral and rotational displacement (improved stability)
Increased denture bearing area = better retention
Root can be used for precision attachments for even better retention
Improved sensory feedback
Decreased psychological trauma
Problems with overdentures?
High degree of maintenance
Potential for caries and peri
Undercuts
Fracture of acrylic
Patient selection for overdentures?
Single complete denture
Cleft palate
Hypodontia
Severe tooth wear
Contraindications for overdentures
Extremes of age Severe debilitation Poor co-operation Mental handicap Any condition which precludes RCT Previous treatment and attitude
How do clinical stages for overdenture differ to complete denture?
Treatment plan including abutment selection
Endo on abutment teeth
What is required for abutment selection?
Good crown:root (canine) No sub-gingival caries RCT possible Symmetrically distributed in the arch Cleansable
List teeth from best to worst abutment
Canines
Premolars
Molars
Incisors
Whats the simplest abutment preparation? Describe?
Doming
- dome the crown = can’t use precision attachments
Relies on retained height of alveolar bone and root to give additional stability adn retention
Benefits of precision attachments
Open face
Decrease palatal coverage
Increased retention
Disadvtagaes of precision attachments
Cost More complicated maintenance Weaken denture base – fracture OH requirements – awkward spaces to clean Increased load to abutments (perio)
Mandibular implant supported over dentures vs maxillary - no. of implants
mandibular = 2 maxillary = 4
