DENTURE BASES
Functions Support & retain denture teeth Stress distribution - surface area Improve esthetics
Materials Acrylic Resin Metal
Acrylic Resin Bases Most common type Allows relining of the base to maintain mucosal support
Advantages Esthetically superior to metal Ease of repair
Disadvantages Dimensional stability - warpage Lower strength/wear resistance than metal Porous - hygiene Low thermal conductivity
Metal Bases Small edentulous spaces Less esthetic (metal show through) no room for gridwork Less esthetic (metal show through)
Beaded Metal Base
Metal Filled Space
Retentive Posts
Advantages Thermal conductivity Swallowing hot substances Improved thermal perception
Advantages Accuracy & Dimensional Stability Minimal warpage (casting imbibtion) Minimal need for posterior palatal seal Minimal abrasion
Advantages Hygiene Metal less porous than resin Less food, plaque & calculus accumulation
Advantages Weight and Bulk Metal bases can be cast thinner than resin bases while maintaining adequate strength
Flange Extension Tooth- tissue supported partial dentures Extend maximally for support & retention No overextension or impingement on movable border tissues
Flange Extension Class I & II RPD’s Posterior extension same as a complete denture Hamular notches, retromolar pads
Flange Extension Soft Tissue Undercuts
Acrylic Resin Finish Lines Internal & external finish lines should not coincide
Replacement Teeth Acrylic denture teeth Cause less attrition than porcelain Easier to arrange, modify & adjust
Replacement Teeth Tooth Form Harmonize with adjacent teeth Shade, shape, length, width & occlusal form Occlusion almost always requires adjustment Poor Occlusogingival Harmony Good Occlusogingival Harmony
Video Clips Cl III Path of Insertion Cl IV Path of Insertion