OVERDENTURES - Part 1

Overdentures is defined as any removable dental prosthesis that covers and resta on one or more remaining natural teeth, the roots of natural teeth and/ or dental implants. Also called as biologic denture, telescopic denture, onlay denture, hybrid denture, root supported denture and superimposed denture.
Rationale - preserves bone, preserves periodontium and establishes favorable crown root ratio.
Preventive Prosthodontics - emphasizes the importance of any procedure that can delay or eliminate future Prosthodontic problems. This concept is highlighted in treatment of overdentures.
Requirements of overdentures -reduction of crown root ratio reduces mobility of tooth, basal seat tissues should be well healed, simple to fabricate, teeth or root should have sound periodontal health, easy manipulation of dentures
Classification of overdentures
1. On the basis of method of abutment preparation - non copings, copings and attachments
2. On the basis of method of retention - copings, attachments, sleeve coping prosthesis, submucosal vital root retention, implant supported
3. On the basis of time of fabrication - immediate overdentures, transitional overdentures and training overdentures
4. On the basis of type of tooth supported overdentures - conventional complete overdentures, immediate complete overdentures
5. On basis of type of design - bare root, telescopic and attachment fixation overdentures
Advantages -
preserves bone
preserves proprioceptive response
provides static stable base
enhances retention
inexpensive approach to restore function in congenital defects such cleft lip, partial anodontia
excellent patient acceptance
easy maintenance
easy conversion to complete denture
reasonable cost
reduces horizontal or torquing forces
roofless denture or open palate is possible
Disadvantages-
susceptible to caries
bony undercuts limits path of insertion
overcontouring or undercontouring
retained teeth susceptible to periodontal breakdown

Indications -
presence of few teeth
younger patients with less teeth
congenital defect
patient with high vault palate and sloping ridges
patient with poorly defined sublingual fold
coperative and motivated patient
Contraindications -
physically and mentally challenged patients
uncooperative and unmotivated patient
teeth with class III mobility
soft tissue and bony defects which cannot be corrected
vertical fracture of tooth
mechanical perforation of tooth or root
horizontal fracture of root below bony crest
broken instrument in root canal

Link for surveying -    • Cast Tilting during Surveying Procedure