INTEGRATED DENTAL PRACTICE 1 — Module RPD DENT5310
2026 Practical Examination — Assessment Sheet
Exam Identification
- Student Name:
- Student Number:
- Seat Number:
Overview
Task: Dental Surveying and Framework Design for RPD — Total 10 points
Instructions
- You have 1.5 h to complete the task
- Write your FULL NAME, STUDENT NUMBER and SEAT NUMBER on the envelope, cast, and assessment sheet
- Read the clinical case (displayed on screen) before answering
- Dental surveying is assessed on the cast; framework design is assessed on both the cast drawing and the answer sheet
- At the end: place the cast and this sheet in the envelope → designated box
Key Vault References
| Source | Use for |
|---|---|
| L2 Components and Classifications | Kennedy classification, Applegate’s rules, components, retention concepts |
| L3 Rests and Rest Seats | Rest-seat dimensions, shape, placement rationale |
| L4 Clasp Assembly | Clasp types, suprabulge vs infrabulge, RPI, aesthetics |
| L5 Major and Minor Connectors | Major and minor connectors with images 308–324 |
| L7 Survey and Design | Full surveying + design workflow |
| DENT1158 Surveying Lecture | Denture Adventure walkthrough of surveying steps |
| DENT 1158 Surveying Project 1 | Tripoding methods, clasp anatomy |
| DENT1158 Project 4 Design Survey Blockout | Block-out, bead line, horizontal shoe extensions |
| Cast Partial Denture Design Kennedy Class I / II / III / IV | Kennedy-class-specific design strategy |
| Partial Dentures - Indications for Clasps and Connectors Overview (rough) | Connector-by-connector indications + drawing tips |
Pre-Exam Video Refresher
Exercises
1) Kennedy Classification (0.25 pt)
Answer: ______________________________________
Tips for classifying quickly L2 Components and Classifications
- Determine the most posterior edentulous space first — it dictates the main class
- Apply Applegate’s rules to resolve ambiguity
- Classify after extractions, not at the moment of loss
- 3rd molar missing and not being replaced → ignore it
- 3rd molar present and used as abutment → include it
- The most posterior edentulous area sets the classification
- Additional spaces = modifications, numbered by count (not location)
- Class IV has no modifications (only one space, crosses the midline)
Memory aid:
- Class I — Bilateral distal extension
- Class II — Unilateral distal extension
- Class III — Tooth-bounded posterior edentulous span
- Class IV — Single span crossing the midline anteriorly
2) Dental Surveying of the Diagnostic Cast (2 pts)
The Nine Purposes of Surveying DENT1158 Surveying Lecture
- Determine the path of placement
- Identify guide planes
- Identify retentive undercut areas
- Evaluate soft-tissue undercuts (vestibule / lingual)
- Evaluate aesthetics (clasp display, “black holes”)
- Determine restorative procedures (re-contouring, crowns)
- Delineate survey lines
- Locate undesirable undercuts for block-out
- Tripod the cast
Surveying Tools Cheat Sheet DENT 1158 Surveying Project 1
| Tool | Purpose |
|---|---|
| Analyzing rod | Check parallelism and undercuts without marking |
| Carbon / graphite marker | Draw the height of contour |
| Undercut gauges (0.25, 0.50, 0.75 mm) | Measure undercut depth for clasp planning |
| Wax trimmer / scalpel | Contour wax during block-out |
2a. Find the Initial POI (0.25 pt)
- Start with the occlusal plane parallel to the surveyor base (zero tilt) DENT1158 Surveying Lecture
- Lock the cast flat on the surveying table
- Use the analyzing rod (not carbon yet) to read proximal parallelism of abutment teeth adjacent to edentulous spaces
2b. Initial Undercut Assessment — verify POI is adequate (0.25 pt)
- Guide-plane check: the rod should contact the occlusal portion of each proximal surface adjacent to an edentulous space. Excessive undercuts here → re-tilt to equalise
- Confirm a 0.25 mm retentive undercut exists buccally (or wherever clasped) on each abutment — if unreachable, tilt the table (Roach or Applegate technique) L7 Survey and Design
- Trade-off: tilting to gain retention on one tooth may introduce unwanted undercuts elsewhere — aim to equalise DENT1158 Surveying Lecture
2c. Height of Contour — RED carbon (0.5 pt)
- Swap the analyzing rod for the red carbon marker
- Mark using the side of the lead (not the tip) — gives a clean single line
- Gently rotate the model against the marker at the fixed tilt
- Mark the survey line on every abutment — only the single highest equator
- Also trace soft-tissue contours that might interfere with the major connector (floor of mouth, vestibule, lingual undercuts, tori) L7 Survey and Design
2d. Tripoding (after the final POI) (0.5 pt)
Tripoding records the chosen POI so the cast can be returned to the exact same tilt. Use one method:
Method A — Tissue-surface bullseyes DENT 1158 Surveying Project 1
- Lock the spindle at a fixed vertical height
- Touch three widely-spaced points on the tissue surface (palate / edentulous ridge)
- Circle each point with a pencil “bullseye” and mark the centre with an “X”
Method B — Cast-base scoring DENT1158 Surveying Lecture
- Score three short vertical lines on the sides and back of the cast base, parallel to the analyzing rod
Warning
Tripod after the final POI is set. Moving the cast after tripoding invalidates the marks.
2e. Retentive Undercut Identification — CoCr (0.5 pt)
- Select the 0.25 mm gauge (one line = CoCr standard) DENT1158 Surveying Lecture
- Raise/lower the gauge until the shank contacts the HOC and the tip contacts the tooth
- That tip position = the retentive point; mark it with a dot — this is where the clasp terminal will sit
Record the location:
- Tooth: ______________
- Surface: ______________ (e.g., disto-buccal, mesio-lingual)
Clasp geometry reminder L4 Clasp Assembly
Only the terminal third of the retentive arm crosses below the HOC. The first two-thirds remain above (passive). A rigid CoCr clasp placed in a 0.75 mm undercut will fracture or damage the abutment — do not exceed 0.25 mm for cast Cr-Co.
Undercut-gauge sizing quick reference:
| Gauge | Use case |
|---|---|
| 0.25 mm (1 line) | Cast Cr-Co clasps (Akers, E-clasp, RPI I-bar) |
| 0.50 mm (2 lines) | Gold alloy / some wrought wire |
| 0.75 mm (3 lines) | Deeper undercut — rarely compatible with cast Cr-Co |
3) Draw the RPD Framework on the Model (2.5 pts)
3a. Rest Seats L3 Rests and Rest Seats
- Shape: rounded triangular, apex toward the centre of the tooth
- Width (B/L): ≈ ½ the inter-cusp distance
- Floor: concave, spoon-shaped — directs force along the long axis of the tooth
- Cingulum / lingual rest: “inverted smile” — convex M-D so the framework can rotate around it (critical for free-end saddles)
- Incisal rest: last resort only — aesthetically poor
Tip
Rest-seat preparation should never perforate enamel. Check thickness before reducing — thin areas on premolars and mandibular molars are common pitfalls.
3b. Grids (Mesh Lattice) L5 Major and Minor Connectors
- Maxilla: grid must cover the tuberosity
- Mandible: extend the grid 2/3 the length of the edentulous ridge
- Grid sits ~1 mm above the tissue to allow acrylic flow underneath
- Use a cast stop (tissue stop) — a small pinpoint of the minor connector contacting the master cast — to prevent framework distortion during acrylic packing (Kennedy I/II especially)
- Internal finish line = 90° butt joint with acrylic
- External finish line = < 90° (beveled) for mechanical retention of the acrylic veneer
3c. Clasps L4 Clasp Assembly
| Situation | Clasp of choice | Why |
|---|---|---|
| Standard tooth-borne abutment | Simple Akers / E-clasp | Most versatile suprabulge clasp |
| Free-end distal extension (Class I/II terminal abutment) | RPI, RPA (Y/G), or I-bar | Stress-breaking; rotates away from abutment under load |
| Aesthetic zone (canines / premolars in smile) | I-bar or Y-bar (infrabulge/Roach) | Minimal metal display; crosses gingival margin at 90° |
| Isolated / tipped molar | Ring clasp with mesial and distal rests | Encircles the tooth; engages mesio-lingual or mesio-buccal undercut |
| Two adjacent tooth-borne sides in same quadrant | Embrasure (double Akers) — or split clasps | Split clasping is more stable (trapezoid > tripod) Cast Partial Denture Design Kennedy Class III |
Universal rules:
- CoCr terminal engages 0.25 mm undercut only
- The flat side of the half-round cross-section faces the tooth (directs flexion in one plane)
- Retentive arm tapers uniformly middle-to-tip
- Reciprocal arm is rigid and sits entirely above HOC on the opposite side of the tooth
Soft-tissue-undercut rule L7 Survey and Design
If the adjacent soft-tissue undercut is > 3 mm, switch to a suprabulge clasp to avoid impinging on tissue. If < 3 mm, infrabulge (I-bar, T-bar) is acceptable.
3d. Major Connector Partial Dentures - Indications for Clasps and Connectors Overview (rough)
Universal drawing rules:
- Cross the midline at right angles — mandatory for rigidity
- Mandibular border clearance: ≥ 3–4 mm (lectures); Denture Adventure uses 3–5 mm DENT1158 Project 4 Design Survey Blockout
- Maxillary border clearance: ≥ 5–6 mm from gingival margins; also ≥ 6 mm from the incisive papilla
- Lingual bar tissue clearance: 0.3–0.5 mm from the lingual mucosa DENT1158 Surveying Lecture
- Posterior maxillary limit: anterior to the vibrating line
- Bead line (maxilla only): at anterior and posterior borders, but not across the median palatal suture or incisive papilla
Connector choice quick reference:
| Kennedy | Maxillary | Mandibular |
|---|---|---|
| I | A-P Palatal Strap (closed oval) / Palatal Plate | Lingual Bar; Linguoplate/Kennedy Bar if splinting |
| II | Palatal Strap / A-P / Palate (width ~ posterior occlusion replaced) | Lingual Bar; Linguoplate if < 7–8 mm vestibule |
| III | Palatal Strap / Single Palatal Bar (small span) / A-P (with ant modification) | Lingual Bar; Linguoplate or Kennedy Bar for stability |
| IV | A-P Palatal Strap / Palatal Plate (horseshoe often insufficient for long spans) | Lingual Bar — watch for ridge atrophy / lingually-inclined posteriors |
3e. Minor Connectors L5 Major and Minor Connectors
- Meet the major connector at a right angle
- Placed in interdental embrasures (minimise tongue interference)
- Cross-section: wider linguobuccal, narrower mesiodistal → minimises gingival-margin coverage
- Proximal plate (RPI): ~1 mm thick; contacts the distal guiding plane fully
4) Adjust Height of Contour / Create Guiding Planes (0.25 pt)
Block-out and ledging are preparation steps for duplication. DENT1158 Project 4 Design Survey Blockout
- Proximal wax block-out: apply wax below the HOC on all abutment proximal surfaces; use the analyzing rod to make them parallel to the POI
- Gingival block-out: lightly block out free gingival margins so rigid framework cannot impinge
- Ledging: create a sharp wax ledge at the survey line where suprabulge clasps will sit — acts as a guide for the wax pattern. Do not ledge guide-plane surfaces or wrought-wire / infrabulge areas
- Horizontal shoe extensions: 0.6 mm wax extensions distal to canines and mesial to molars → clean internal finish line for the acrylic-metal junction
5) Draw the Design on the Answer Sheet (2.5 pts)
Colour Code
| Colour | Component |
|---|---|
| 🔴 Red | Rests |
| 🟢 Green | Retentive arm |
| 🔵 Blue | Reciprocative (bracing) arm + major/minor connectors |
| ⚫ Black / pencil | Saddle (mesh area) |
Drawing order
- Outline edentulous areas and saddles (pencil/black)
- Place rest dots (red)
- Trace retentive arms (green) — first 2/3 above HOC, terminal 1/3 crosses below
- Trace reciprocal arms (blue) — entirely above HOC, on the opposite side of the tooth to the retentive arm
- Draw minor connectors (blue) meeting the major connector at right angles
- Draw the major connector (blue) — respect the minimum distances from gingival margins
Drawing quality tips Cast Partial Denture Design Kennedy Class I
- Symmetry over the arch is a sign of balanced design — avoid straight-line frameworks
- Simplicity — use the simplest clasp form that satisfies retention needs
- Future-proof — for teeth with guarded prognosis, design so a replacement tooth can be added to the acrylic base without reworking the framework
6) Component → Biomechanical Function Table (2.5 pts)
Instruction: According to your design, fill in the table to show which component provides each requirement. Use the general guide below — adapt to match the clasps and connector you actually drew for this case.
| Requirement | Components that typically provide it |
|---|---|
| Support (resists vertical seating force toward tissue) | Rests — occlusal, cingulum, incisal — transmit load along the long axis of the abutment; denture base / saddle on the residual ridge (tissue-borne portion, major in Kennedy I/II); proximal plate contributes vertical support in RPI designs; maxillary major connector (palatal mucosa) adds vertical support only in the maxilla — the mandibular major connector provides no vertical support L5 Major and Minor Connectors |
| Retention (resists vertical dislodgement away from tissue) | Retentive clasp arm — terminal third engaging a 0.25 mm undercut (CoCr) — Akers, I-bar, T-bar, ring, etc.; guide-plane frictional retention (parallel proximal surfaces resist vertical lift); adhesion / cohesion of denture base to tissue (minor but real); precision attachments or implants when present |
| Indirect Retention (resists rotation of distal-extension bases away from tissue) | Indirect retainers — rests placed perpendicular to and as far from the fulcrum line as possible; typically cingulum rests on canines or occlusal rests on premolars opposite the distal-extension side; linguoplate / Kennedy bar can contribute when present; guide planes anterior to the fulcrum line also resist rotation. Only relevant in Kennedy I, II, and long-span IV L2 Components and Classifications |
| Reciprocation / Bracing (counteracts the force exerted by the retentive arm during insertion) | Reciprocal arm on the opposite side of the tooth, entirely above the HOC; in RPI designs the minor connector + proximal plate provide reciprocation (no separate arm needed); linguoplate reciprocates against the retentive arms of anterior clasps; guide planes with their contacting minor connectors also reciprocate L5 Major and Minor Connectors |
| Stabilization (resists horizontal forces during function) | All rigid components contacting a tooth at or above the HOC: minor connectors crossing interdentally, reciprocal arms, proximal plates, guide-plane contacts, linguoplate, and the major connector itself (through cross-arch rigidity). Rest seats with flat floors also resist lateral sliding |
Direct vs Indirect Retention
- Direct retention resists dislodgement of the whole prosthesis from the ridge (sticky foods, chewing gum)
- Indirect retention prevents rotation of a free-end saddle away from tissue — it activates only when the saddle tries to lift. In a pure Class III case, indirect retention is usually not needed L2 Components and Classifications
End-of-Exam Checklist
- Full name, student number, seat number on envelope, cast, and this sheet
- Kennedy classification written (section 1)
- Cast: initial POI set → HOC marked in red → tripod marks placed → retentive undercut dots marked
- Location of retentive undercut written in section 2e
- Framework drawn on cast — rests, grids, clasps, major and minor connectors
- Framework drawn on answer sheet in the correct colours
- Section 6 table completed based on the design you drew
- Cast + sheet placed in envelope → designated box