DENTURE BASESDENTURE BASESDENTURE BASESDENTURE BASES

FunctionsFunctionsFunctionsFunctions

Support & retain denture Support & retain denture teethteeth

Stress distribution - surface Stress distribution - surface area area

Improve estheticsImprove esthetics

Support & retain denture Support & retain denture teethteeth

Stress distribution - surface Stress distribution - surface area area

Improve estheticsImprove esthetics

MaterialsMaterialsMaterialsMaterials

Acrylic ResinAcrylic Resin MetalMetal

Acrylic ResinAcrylic Resin MetalMetal

Acrylic Resin BasesAcrylic Resin BasesAcrylic Resin BasesAcrylic Resin Bases

Most common typeMost common type Allows relining of the Allows relining of the

base to maintain base to maintain mucosal supportmucosal support

Most common typeMost common type Allows relining of the Allows relining of the

base to maintain base to maintain mucosal supportmucosal support

AdvantagesAdvantagesAdvantagesAdvantages

Esthetically superior to Esthetically superior to metal basesmetal bases

Ease of repairEase of repair

Esthetically superior to Esthetically superior to metal basesmetal bases

Ease of repairEase of repair

DisadvantagesDisadvantagesDisadvantagesDisadvantages

Dimensional stability- Dimensional stability- warpagewarpage

Lower strength/wear Lower strength/wear resistance than metalresistance than metal

Porous - hygienePorous - hygiene Low thermal conductivityLow thermal conductivity

Dimensional stability- Dimensional stability- warpagewarpage

Lower strength/wear Lower strength/wear resistance than metalresistance than metal

Porous - hygienePorous - hygiene Low thermal conductivityLow thermal conductivity

Metal BasesMetal BasesMetal BasesMetal Bases

Small edentulous spaces (no room for Small edentulous spaces (no room for gridworkgridwork

Less esthetic (metal show through)Less esthetic (metal show through)

Small edentulous spaces (no room for Small edentulous spaces (no room for gridworkgridwork

Less esthetic (metal show through)Less esthetic (metal show through)

Beaded Metal BaseBeaded Metal BaseBeaded Metal BaseBeaded Metal Base

Metal Filled SpaceMetal Filled SpaceMetal Filled SpaceMetal Filled Space

Retentive PostsRetentive PostsRetentive PostsRetentive Posts

AdvantagesAdvantagesAdvantagesAdvantages

Thermal conductivityThermal conductivity– Swallowing hot substancesSwallowing hot substances– Improved thermal perceptionImproved thermal perception

Thermal conductivityThermal conductivity– Swallowing hot substancesSwallowing hot substances– Improved thermal perceptionImproved thermal perception

AdvantagesAdvantagesAdvantagesAdvantages

Accuracy & Dimensional StabilityAccuracy & Dimensional Stability

– Minimal warpage (casting imbibtion)Minimal warpage (casting imbibtion)– Minimal need for a posterior palatal Minimal need for a posterior palatal

sealseal– Minimal abrasionMinimal abrasion

Accuracy & Dimensional StabilityAccuracy & Dimensional Stability

– Minimal warpage (casting imbibtion)Minimal warpage (casting imbibtion)– Minimal need for a posterior palatal Minimal need for a posterior palatal

sealseal– Minimal abrasionMinimal abrasion

AdvantagesAdvantagesAdvantagesAdvantages

Hygiene Hygiene

– Metal less porous than resinMetal less porous than resin– Less food, plaque & calculus Less food, plaque & calculus

accumulationaccumulation

Hygiene Hygiene

– Metal less porous than resinMetal less porous than resin– Less food, plaque & calculus Less food, plaque & calculus

accumulationaccumulation

AdvantagesAdvantagesAdvantagesAdvantages

Weight and BulkWeight and Bulk

– Metal bases can be cast Metal bases can be cast thinner than resin bases while thinner than resin bases while maintaining adequate maintaining adequate strength strength

Weight and BulkWeight and Bulk

– Metal bases can be cast Metal bases can be cast thinner than resin bases while thinner than resin bases while maintaining adequate maintaining adequate strength strength

Flange ExtensionFlange ExtensionFlange ExtensionFlange Extension

Tooth- tissue supported partial Tooth- tissue supported partial dentures should be maximally dentures should be maximally extended for support & retentionextended for support & retention

No overextension or impingement No overextension or impingement on movable border tissues on movable border tissues

Tooth- tissue supported partial Tooth- tissue supported partial dentures should be maximally dentures should be maximally extended for support & retentionextended for support & retention

No overextension or impingement No overextension or impingement on movable border tissues on movable border tissues

Flange ExtensionFlange ExtensionFlange ExtensionFlange Extension

Class I & II RPD’sClass I & II RPD’s

– Posterior extension same as a Posterior extension same as a complete denturecomplete denture

– Hamular notches, retromolar Hamular notches, retromolar padspads

Class I & II RPD’sClass I & II RPD’s

– Posterior extension same as a Posterior extension same as a complete denturecomplete denture

– Hamular notches, retromolar Hamular notches, retromolar padspads

Flange ExtensionFlange ExtensionFlange ExtensionFlange Extension

Soft Tissue UndercutsSoft Tissue Undercuts Soft Tissue UndercutsSoft Tissue Undercuts

Do Not RelieveExcessively

Do Not RelieveExcessively

Shorten FlangeShorten FlangeDeep UndercutDeep Undercut

XX

Acrylic Resin Finish LinesAcrylic Resin Finish LinesAcrylic Resin Finish LinesAcrylic Resin Finish Lines

Internal & external finish Internal & external finish lines should not coincidelines should not coincide

Internal & external finish Internal & external finish lines should not coincidelines should not coincide

a

major connectoredentulous ridge

slight undercut

staggered finish linesgridwork

Acrylic denturebase

Replacement TeethReplacement TeethReplacement TeethReplacement Teeth

Acrylic denture teethAcrylic denture teeth

– Cause less attrition than Cause less attrition than porcelainporcelain

– Easier to arrange, modify & Easier to arrange, modify & adjustadjust

Acrylic denture teethAcrylic denture teeth

– Cause less attrition than Cause less attrition than porcelainporcelain

– Easier to arrange, modify & Easier to arrange, modify & adjustadjust

Replacement TeethReplacement TeethReplacement TeethReplacement Teeth

Tooth FormTooth Form

– Harmonize with Harmonize with adjacent teethadjacent teeth

– Shade, shape, length, Shade, shape, length, width & occlusal formwidth & occlusal form

– Occlusion almost Occlusion almost always requires always requires adjustmentadjustment

Tooth FormTooth Form

– Harmonize with Harmonize with adjacent teethadjacent teeth

– Shade, shape, length, Shade, shape, length, width & occlusal formwidth & occlusal form

– Occlusion almost Occlusion almost always requires always requires adjustmentadjustment