12. rpd protocol & framework

7/30/2019 12. RPD Protocol & Framework

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Clinical Protocol forRemovable 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 teethSevere 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 approvedbefore 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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Material of Choice

Polyvinyl Siloxane


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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 seatsRetentive areas

Heights of contour


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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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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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Peripheries well defined

Accurately records supporting tissues

Allows for all elements of design


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Mandible

Measure FGM to floor ofmouth

Record measurements

Transfer to cast - inferiorframework border


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No significant areas of

burn through

Border molding not covered

Displaces the tissue

Change in contour caused bythe border molding


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Impression integrity

No significant tearsNot separated from tray


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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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Box & pour impression

Survey & tripodize Draw design

Send to Lab with Work

Authorization forframework 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 Summary1. Diagnosis, Treatment Plan, Hygiene

2. Diagnostic Casts

3. Draw Design & list abutment modifications4. 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 Summary9. Draw design on 2nd cast

10. Instructor approval/corrections

11. Cast to Lab with 1st pour & prescription

12. Inspect framework waxup

13. Framework Adjustment

14. Altered Cast impression, if needed

15. Try-in with teeth in wax

16. Process, deliver to patient

12. rpd protocol & framework

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