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DENTURE BASES

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					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 bases
    Ease of repair
Disadvantages

     Dimensional stability-
      warpage
     Lower strength/wear
      resistance than metal
     Porous - hygiene
     Low thermal conductivity
Metal Bases
     Small edentulous spaces (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 a 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 should be maximally
      extended 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



                       X
                       X




  Deep Undercut
  Deep Undercut   Do Not Relieve
                  Do Not Relieve   Shorten Flange
                                   Shorten Flange
                   Excessively
                   Excessively
Acrylic Resin Finish Lines

     Internal & external finish
      lines should not coincide

                             edentulous ridge
                                                   major connector
     Acrylic denture
          base

                                                staggered finish lines
                  gridwork

                                           slight undercut
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

				
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