RPD Design

Question 1

Max Major connectors Purposes

Answer 1

• Connects all elements
• Cross arch stability
• strength
• Must be beaded

Question 2

Palatal Strap Specs

Answer 2

• Must be keep metal at least 6 mm from gingival margin
• Min width 8-10mm
• Usually useful in a tooth-borne edentulous sapce
• Should cross palate at right angles
• Placed curves near one side or the other

Question 3

A-P Strap Specs

Answer 3

• Must be 6 mm from gingival margin
• Cross palate at right angles
• Most versatile for max
• Post strap should be flat and at least 8 mm in width
• Space btw ant and post straps should be at least 15mm

Question 4

Beading Purposes

Answer 4

• Maintain positive contact with palatal tissues
• Provides bulk on the edges to allow the metal to be thinned
• Should be 0.5-1mm thick, thinnes around midline
• Increase rigidity of connector

Question 5

Lingual Bar Specs

Answer 5

• 8 mm from gingival margin to floor of mouth needed
  
  • superior border must be at least 4 mm from gingival margin
  • Bar thickness 4 mm

Question 6

Lingual bar contraindications (4)

Answer 6

• Inoperable tori
• High frenum
• Undercut on lingual ridge
• Lingually inclined teeth

Question 7

Lingual Bar Pros(3) and Cons (2)

Answer 7

• Pros
  
  • No contact with teeth
  • Min contact with tissues
  • Half pear cross section
• Cons
  
  • Flexible
  • Cannot add more teeth

Question 8

Linguplate Specs, when to use

Answer 8

• Used when anatomy is not conducive to ling bar
• or to help brace teeth
• Place scalloped superior border at height of contour

Question 9

Linguplate Contraindications

Answer 9

Lingually inclined teeth

Diastemas

Question 10

Linguplate Pros (3) Cons 1

Answer 10

• Pros
  
  • More support stabilization
  • Indirect retention
  • Teeth can be added
• Cons
  
  • Prevents self cleaning

Question 11

Occlusal rests specs

Answer 11

• Depth 1.5 mm
• Width 2.5 mm
• 1/3 bucco-lingual width

Question 12

Cingulum rest specs

Answer 12

• Internal
  
  • tilted 90 degrees
  • deeper gingivally near axial
  • 1mm depth
• External
  
  • chevron shaped consider enamel thickness for location
  • Consider occlusion, must have room to connect to major connector

Question 13

C- clasp

Answer 13

• preferred for tooth bound areas
• Half circle cross section only flexes in single plane
• Retentive arm
  
  • tapered
  • Originates above HOC
  • Terminates under HOC engages undercut
• Reciprocated arm
  
  • Non tapered
  • Originates and ends above HOC

Question 14

RPI/I Bar Specs

Answer 14

• Rest
  
  • Mesial rest seat
• Proximal Plate
  
  • Lateral endentolous space
• I Bar
  
  • ).01 undercut
  • On FACIAL, slight m to center
• Infrabulge
• Encirclement

Question 15

RPI/I bar contraindications

Answer 15

High frenum attachments

Improper tooth undercuts

Deep tissue Undercuts (food Impaction)

Question 16

Combo Clasp

Answer 16

• AKA wrouught wire
• Looks similar to C clasp
• Contains
  
  • cast elements (reciprication/prox plate)
  • Wrought wire for retention
• More flexible due to cross section of the wire
• Deeper retention 0.02

Question 17

Indirect retention

Answer 17

• Resists leverage when chewing of distal extension
  
  • from forces away from residual ridge
• Placed anterior to retentive arms on distal extension RPDs
• Second support w fulcrum to resist lever action
• Usually placed on canine

Question 18

Tissue Stops

Answer 18

• Metal finger that contacts the cast to ensure denture base is floating once acrylic is added

Question 19

Guide Planes/ Proximal Plates

Answer 19

• Guide planes are vertical and parallel with crresponding metal plates
• Allows for single path of insertion
• Placed adjacent to edentolous space

Question 20

Guide planes prep and concerns

Answer 20

• 1/3 BL width
• 1/3-1/2 Height
• Min 2mmx2mm
• NOT in gingival 1/3
• Concerns
  
  • Over prep
    
    • Too much contact can lead to unfavorable forces when placing removing
    • Dentin exposure