1. DENTURE BASES

2. FunctionsFunctions Support & retain denture teeth Support & retain denture teeth Stress distribution - surface area Stress distribution - surface area Improve esthetics Improve esthetics Support & retain denture teeth Support & retain denture teeth Stress distribution - surface area Stress distribution - surface area Improve esthetics Improve esthetics

3. MaterialsMaterials Acrylic Resin Acrylic Resin Metal Metal Acrylic Resin Acrylic Resin Metal Metal

4. Acrylic Resin Bases Most common type Most common type Allows relining of the base to maintain mucosal support Allows relining of the base to maintain mucosal support Most common type Most common type Allows relining of the base to maintain mucosal support Allows relining of the base to maintain mucosal support

5. AdvantagesAdvantages Esthetically superior to metal bases Esthetically superior to metal bases Ease of repair Ease of repair Esthetically superior to metal bases Esthetically superior to metal bases Ease of repair Ease of repair

6. DisadvantagesDisadvantages Dimensional stability- warpage Dimensional stability- warpage Lower strength/wear resistance than metal Lower strength/wear resistance than metal Porous - hygiene Porous - hygiene Low thermal conductivity Low thermal conductivity Dimensional stability- warpage Dimensional stability- warpage Lower strength/wear resistance than metal Lower strength/wear resistance than metal Porous - hygiene Porous - hygiene Low thermal conductivity Low thermal conductivity

7. Metal Bases Small edentulous spaces (no room for gridwork Small edentulous spaces (no room for gridwork Less esthetic (metal show through) Less esthetic (metal show through) Small edentulous spaces (no room for gridwork Small edentulous spaces (no room for gridwork Less esthetic (metal show through) Less esthetic (metal show through)

8. Beaded Metal Base

9. Metal Filled Space

10. Retentive Posts

11. AdvantagesAdvantages Thermal conductivity Thermal conductivity –Swallowing hot substances –Improved thermal perception Thermal conductivity Thermal conductivity –Swallowing hot substances –Improved thermal perception

12. AdvantagesAdvantages Accuracy & Dimensional Stability Accuracy & Dimensional Stability –Minimal warpage (casting imbibtion) –Minimal need for a posterior palatal seal –Minimal abrasion Accuracy & Dimensional Stability Accuracy & Dimensional Stability –Minimal warpage (casting imbibtion) –Minimal need for a posterior palatal seal –Minimal abrasion

13. AdvantagesAdvantages Hygiene Hygiene –Metal less porous than resin –Less food, plaque & calculus accumulation Hygiene Hygiene –Metal less porous than resin –Less food, plaque & calculus accumulation

14. AdvantagesAdvantages Weight and Bulk Weight and Bulk –Metal bases can be cast thinner than resin bases while maintaining adequate strength Weight and Bulk Weight and Bulk –Metal bases can be cast thinner than resin bases while maintaining adequate strength

15. Flange Extension Tooth- tissue supported partial dentures should be maximally extended for support & retention Tooth- tissue supported partial dentures should be maximally extended for support & retention No overextension or impingement on movable border tissues No overextension or impingement on movable border tissues Tooth- tissue supported partial dentures should be maximally extended for support & retention Tooth- tissue supported partial dentures should be maximally extended for support & retention No overextension or impingement on movable border tissues No overextension or impingement on movable border tissues

16. Flange Extension Class I & II RPDs Class I & II RPDs –Posterior extension same as a complete denture –Hamular notches, retromolar pads Class I & II RPDs Class I & II RPDs –Posterior extension same as a complete denture –Hamular notches, retromolar pads

17. Flange Extension Soft Tissue Undercuts Soft Tissue Undercuts

18. Acrylic Resin Finish Lines Internal & external finish lines should not coincide Internal & external finish lines should not coincide

19. Replacement Teeth Acrylic denture teeth Acrylic denture teeth –Cause less attrition than porcelain –Easier to arrange, modify & adjust Acrylic denture teeth Acrylic denture teeth –Cause less attrition than porcelain –Easier to arrange, modify & adjust

20. Replacement Teeth Tooth Form Tooth Form –Harmonize with adjacent teeth –Shade, shape, length, width & occlusal form –Occlusion almost always requires adjustment Tooth Form Tooth Form –Harmonize with adjacent teeth –Shade, shape, length, width & occlusal form –Occlusion almost always requires adjustment

21. Replacement Tooth Modification

22. Occlusal Scheme Varies from fully balanced (opposing a complete denture), to anterior disclusion Varies from fully balanced (opposing a complete denture), to anterior disclusion As more of the occlusal table is involved, the more a balanced occlusal scheme may be of benefit As more of the occlusal table is involved, the more a balanced occlusal scheme may be of benefit Varies from fully balanced (opposing a complete denture), to anterior disclusion Varies from fully balanced (opposing a complete denture), to anterior disclusion As more of the occlusal table is involved, the more a balanced occlusal scheme may be of benefit As more of the occlusal table is involved, the more a balanced occlusal scheme may be of benefit