Clinical Protocol for Removable Partial Dentures

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Clinical Protocol for Removable Partial Dentures
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Diagnosis Treatment Planning

• Gather diagnostic info
• Make preliminary impressions
• Pour diagnostic casts

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Mounting Diagnostic Casts

• If required
• Extruded teeth
• Severe attrition
• Insufficient interarch space
• Deep overbite, etc.
• use Semiadjustable Articulator

4
Formulate Treatment Plan

• Overall Treatment Plan
• Specific RPD Treatment Plan
• Select abutments, direct retainers
• Major connectors
• Position of rests, g.p., bracing retentive arms

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Critical!!!

• When RPD is part of treatment
• Draw design on surveyed cast
• Design approved before any treatment started
• Affects direct restorations
• Can influence need for/preparations for crowns
• Insures RPD can be completed successfully
• Survey, tripod, heights of contour

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Formulate Treatment Plan

• Discuss with instructor prior to discussing with
  patient
• Provide rationale for design

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Final Impressions for Partial Dentures

• Framework Impression
• Altered Cast Impression

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Framework Impression

• Border Molded Custom Tray
• Tray that is made for patient
• Mold tray periphery with thermoplastic compound

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Framework Impression

• Material of Choice
• Polyvinyl Siloxane

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Framework Impression

• Polyvinyl siloxanes
• Excellent dimensional stability
• Good tear strength
• No taste
• Glove contamination
• Relatively hydrophobic - improved

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Prior to the Final Impression

• No plaque or calculus
• Healthy soft tissues
• Initial therapy complete

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Prior to the Final Impression

• Make alginate impression to check
• Guiding planes
• Rest seats
• Retentive areas
• Heights of contour

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Framework Impression

• Syringe low viscosity material
• Around abutment teeth
• Over occlusal surfaces
• Use care in rest seats
• Do not over fill trays - overextension

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Framework Impression

• Medium viscosity in tray
• Increased filler content
• less shrinkage
• Less displacement of soft tissues than high
  viscosities

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Evaluating the Impression

• Absence of Significant Voids
• Any area where metal contacts abutment (e.g.
  rests, minor connectors)
• Any area where major or minor connectors contact
  soft tissue

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Evaluating the Impression

• Peripheries well defined
• Accurately records supporting tissues
• Allows for all elements of design

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Evaluating the Impression

• Mandible
• Measure FGM to floor of mouth
• Record measurements
• Transfer to cast - inferior framework border

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Evaluating the Impression

• No significant areas burn-through
• Border molding not covered
• Displaces the tissue
• Change in contour caused by the border molding

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Evaluating the Impression

• Impression integrity
• No significant tears
• Not separated from tray

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Evaluating the Impression

• Impression integrity
• No significant tears
• Not separated from tray

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Evaluating the Impression

• Critical Anatomy Recorded
• Vestibular depths
• Hamular notches (marked)
• Vibrating line (marked)
• Retromolar pads
• Frenal attachments
• Floor of mouth (measured)

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Preparation for Impression

• Practice inserting removing tray
• Dry tissues

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Preparation for Impression

• Block out
• large embrasures
• bridge pontics
• Dont cover occlusion or framework surfaces

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Preparation for Impression

• Teeth must be DRY for wax to stick

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Dont Reseat Impression

• Wont fully seat over undercuts

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Framework Impression

• Box pour impression
• Survey tripodize
• Draw design
• Send to Lab with Work Authorization for framework
  fabrication

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Master Cast

• Pour in improved dental stone
• Type IV (Silky Rock)
• Vacuum mix stone
• Allow to set at least 1 hour
• strength to resist fracture

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Master Casts

• No significant bubbles or flaws
• Teeth not fractured from cast
• Includes all anatomical surfaces of final
  impressions
• Includes 3-4 mm. land area

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Master Cast

• Base parallel ridge
• 12 mm (.5) thick (minimum)
• Evidence of a dense stone surface
• Clean well trimmed (keep wet while trimming)

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Pour Secondary Cast

• Draw design on secondary cast
• Checked/corrected with instructor
• Correct design on 2nd cast
• Send to lab with 1st poured cast
• lab will transfer the design to this cast

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RPD Protocol Summary

1. Diagnosis, Treatment Plan, Hygiene
2. Diagnostic Casts
3. Draw Design list abutment modifications
4. Instructor Approval
5. Abutment modifications
6. Preliminary impression to check mod.s
7. Final Framework Impression
8. Pour two casts

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RPD Protocol Summary

1. Draw design on 2nd cast
2. Instructor approval/corrections
3. Cast to Lab with 1st pour prescription
4. Inspect framework waxup
5. Framework Adjustment
6. Altered Cast impression, if needed
7. Try-in with teeth in wax
8. Process, deliver to patient