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

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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 of 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

• 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 occluding 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

• Diagnosis, Treatment Plan, Hygiene
• Diagnostic Casts
• Draw Design list abutment modifications
• Instructor Approval
• Abutment modifications
• Preliminary impression to check mod.s
• Final Framework Impression
• Pour two casts

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RPD Protocol Summary

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