Acrylic RPD Clinical Sequence — Form 26
Paste-ready chairside checklists for an acrylic-based removable partial denture (mucosa-supported, wrought-wire clasps added after processing). Extracted from Clinical Sequence for Partial Dentures and the RPD lecture series. Use Sequence A for an acrylic RPD with no OVD change, or Sequence B when increasing the OVD.
Acrylic RPD — when to choose it (indications & caveats)
- Interim / transitional: provisional prosthesis to restore aesthetics/function while healing, during the control phase, or before a definitive appliance. Easy to repair and to add teeth if further loss is expected.
- Immediate partial: fabricated pre-extraction, inserted immediately after extraction — stabilises the clot and maintains adjacent/opposing tooth position.
- Compromised abutments: acrylic is tissue/mucosa-supported, so it distributes load to the soft tissue rather than loading periodontally weak or mobile teeth — preferred when abutments cannot safely bear a cast framework.
- Cost / simplicity: cheaper and simpler to manufacture than Co-Cr.
- Limitations: bulkier; higher fracture risk (needs adequate acrylic thickness); poorer retention/longevity than cast metal.
With severe loss of vertical dimension there may be insufficient prosthetic space for adequate acrylic thickness (≥ ~2 mm) → a metal framework is required instead. Reassess before committing to acrylic.
Key differences from the Co-Cr template
- No framework fabrication and no framework try-in visit — the master model is not duplicated, surveyed or cast. MMR is recorded on a record base + wax rim built on the master model instead.
- Generally no second-stage biomechanical mouth prep (rest seats, guide planes, height-of-contour changes, survey crowns) — only the control phase applies. (Acrylic partials may still carry wrought-wire clasps engaging ~0.75 mm undercuts and occasionally simple rests — this is not “zero tooth contact.”)
- Clasps are added after acrylic processing (wrought-wire), not cast into a framework.
- Simpler lab prescription: master model + bite registration + lab slip (clasp positions, teeth to be replaced, shade). No study model with framework design, no major-connector/clasp-type/rest-location detail.
- Facebow mounting and a new base & wax rim on the master model are still required.
Sequence A — Acrylic RPD, NO OVD increase
VISIT 1 — Preliminary impressions
- Alginate prelim impressions U/L (stock trays, periphery wax)
- Bite reg: Kennedy III/IV (no free-end saddle) → conventional; Kennedy I/II → digital bite reg (video the contacts first)
- Lab: study models (type 3 gypsum), base & rim if needed
VISIT 2 — Jaw relations, tooth selection & design
- Try in base & rim (chairside technique: Registration Sequence for a Removable Partial Denture)
- Record CR (leaf gauge, confirmative/MIP), facebow, protrusive
- OVD = RVD - freeway; verify “Mississippi 66” (closest speaking space)
- Mark midline / canines / smile line
- Select shade & mould
- Plan clasp positions + teeth to be replaced (NO framework survey/design/cast)
- Note any minimal tooth modification only if needed (usually none — tissue-supported)
- Lab: mount on semi-adjustable articulator; make special (custom) tray on the study model
VISIT 3 — Mouth prep & final impression (KEY)
- Complete control phase first (perio/endo/resto/surgical)
- Generally NO rest-seat / guide-plane prep (mucosa-supported)
- Try-in custom tray (not overextended); copy frenula
- Border-mould (putty) -> light-body PVS -> heavy-body in tray
- Take final elastomeric impression
- Lab: bead/box/pour master model (NO duplication, NO framework); make new base & wax rim
VISIT 4 — MMR on record base (replaces framework try-in)
- Try in the new record base & wax rim built on the master model; check adaptation/stability
- Record MMR (facebow + CR at the established OVD)
- Confirm midline / occlusal plane / lip support on the rim
- Lab: cross-mount master models; tooth setting
VISIT 5 — Wax try-in
- Check occlusion, OVD, aesthetics, neutral zone
- Move teeth, don’t grind; get patient approval
- Lab: process denture + add wrought-wire clasps after processing
VISIT 6 — Insertion
- Inspect base: voids (->lab), nodules/sharp edges (remove chairside), overextensions (trim)
- Check retention, stability, extension, occlusion (articulating paper), OVD, appearance
- Check/adjust clasp engagement (wrought wire — bend to adjust; do not over-tighten)
- Reline if poor saddle adaptation (bite reg BEFORE pickup impression)
- Care / cleaning / adaptation instructions
VISIT 7 — Review (~2 weeks)
- Assess adaptation, address complaints
- Identify true pressure points (fit checker / light body), trim gradually
- Re-check clasp retention; add teeth later if further extractions occur
Sequence B — Acrylic RPD, WITH OVD increase
VISIT 1 — Preliminary impressions
- Alginate prelim impressions U/L (stock trays, periphery wax)
- Lab: study models, base & rim
VISIT 2 — Jaw relations at NEW OVD (reorganised)
- Establish target increased OVD on wax rim (NOT MIP)
- Extraoral refs (nose-chin), RVD - freeway; verify phonetics
- Facebow + jaw relation at the new VD
- Select shade & mould; mark landmarks
- Lab: mount at new OVD
VISIT 3 — Diagnostic wax-up at new OVD
- Wax up to new OVD; confirm occlusal plane
- Plan composite build-ups and/or restorations to support new VD
- Finalise design: clasp positions, teeth to replace, shade (no framework)
- Lab: special tray
VISIT 3b/4 — Stabilise the new OVD (extra step)
- Place composite build-ups and/or restorations to the planned OVD
- Verify comfort, phonetics, occlusion; allow adaptation period
- NOTE: heavily worn dentitions -> consider prosthodontic referral
VISIT 4 onward — REJOIN SEQUENCE A (from Mouth prep / final impression onward)
- Mouth prep, final impression, MMR on record base, wax try-in, insertion, review
- Acrylic denture built to the INCREASED OVD (can itself carry the interim OVD)
- Replace provisional composites with definitive restorations later if planned
Copy-pastable checklists
Sequence A — Acrylic RPD, NO OVD increase
VISIT 1 — Preliminary impressions
- Alginate prelim impressions U/L (stock trays, periphery wax)
- Bite registration
- Lab: study models (type 3 gypsum), base & rim if needed
VISIT 2 — Jaw relations, tooth selection & design
- Try in base & rim
- Record CR (leaf gauge, confirmative/MIP), facebow, protrusive
- OVD = RVD - freeway; verify "Mississippi 66"
- Mark midline / canines / smile line; select shade & mould
- Plan clasp positions + teeth to replace (NO framework survey/cast)
- Note minimal tooth mod only if needed (usually none)
- Lab: mount on articulator; make special (custom) tray
VISIT 3 — Mouth prep & final impression (KEY)
- Complete control phase first (perio/endo/resto/surgical)
- Generally NO rest-seat / guide-plane prep (mucosa-supported)
- Try-in custom tray (not overextended)
- Border-mould (putty) -> light-body PVS -> heavy-body in tray
- Take final elastomeric impression
- Lab: bead/box/pour master model (NO duplication, NO framework); make new base & wax rim
VISIT 4 — MMR on record base (replaces framework try-in)
- Try in new base & wax rim on master model; check adaptation
- Record MMR (facebow + CR at established OVD)
- Confirm midline / occlusal plane / lip support
- Lab: cross-mount, tooth setting
VISIT 5 — Wax try-in
- Check occlusion, OVD, aesthetics, neutral zone
- Move teeth, don't grind; get patient approval
- Lab: process denture + add wrought-wire clasps after processing
VISIT 6 — Insertion
- Inspect base: voids (->lab), nodules/sharp edges (remove chairside), overextensions (trim)
- Check retention, stability, extension, occlusion (articulating paper), OVD, appearance
- Check/adjust wrought-wire clasp engagement (bend to adjust)
- Reline if poor saddle adaptation (bite reg BEFORE pickup impression)
- Care / cleaning / adaptation instructions
VISIT 7 — Review (~2 weeks)
- Assess adaptation, address complaints
- Identify true pressure points (fit checker / light body), trim gradually
- Re-check clasp retention; add teeth later if further extractions
Sequence B — Acrylic RPD, WITH OVD increase
VISIT 1 — Preliminary impressions
- Alginate prelim impressions U/L (stock trays, periphery wax)
- Lab: study models, base & rim
VISIT 2 — Jaw relations at NEW OVD (reorganised)
- Establish target increased OVD on wax rim (NOT MIP)
- Extraoral refs (nose-chin), RVD - freeway; verify phonetics
- Facebow + jaw relation at the new VD
- Select shade & mould; mark landmarks
- Lab: mount at new OVD
VISIT 3 — Diagnostic wax-up at new OVD
- Wax up to new OVD; confirm occlusal plane
- Plan composite build-ups and/or restorations to support new VD
- Finalise design: clasp positions, teeth to replace, shade (no framework)
- Lab: special tray
VISIT 3b/4 — Stabilise the new OVD (extra step)
- Place composite build-ups and/or restorations to planned OVD
- Verify comfort, phonetics, occlusion; allow adaptation period
- NOTE: heavily worn dentitions -> consider prosthodontic referral
VISIT 4 — Mouth prep & final impression (KEY, at NEW OVD)
- Complete control phase first (perio/endo/resto/surgical)
- Generally NO rest-seat / guide-plane prep (mucosa-supported)
- Try-in custom tray (not overextended)
- Border-mould (putty) -> light-body PVS -> heavy-body in tray
- Take final elastomeric impression
- Lab: bead/box/pour master model (NO duplication, NO framework); make new base & wax rim
VISIT 5 — MMR on record base (replaces framework try-in)
- Try in new base & wax rim on master model; check adaptation
- Record MMR (facebow + CR at the NEW OVD)
- Confirm midline / occlusal plane / lip support
- Lab: cross-mount, tooth setting
VISIT 6 — Wax try-in
- Check occlusion, NEW OVD, aesthetics, neutral zone
- Move teeth, don't grind; get patient approval
- Lab: process denture + add wrought-wire clasps after processing
VISIT 7 — Insertion
- Inspect base: voids (->lab), nodules/sharp edges (remove chairside), overextensions (trim)
- Check retention, stability, extension, occlusion (articulating paper), NEW OVD, appearance
- Check/adjust wrought-wire clasp engagement (bend to adjust)
- Reline if poor saddle adaptation (bite reg BEFORE pickup impression)
- Care / cleaning / adaptation instructions
- Acrylic denture built to the INCREASED OVD (can itself carry the interim OVD)
VISIT 8 — Review (~2 weeks)
- Assess adaptation, address complaints
- Identify true pressure points (fit checker / light body), trim gradually
- Re-check clasp retention; add teeth later if further extractions
- Replace provisional composites with definitive restorations later if planned