Prosthodontics Prometric exam questions with answers

1. Question 1Complete denturesmedium

   At try-in, which speech sounds are best used to check the incisal edge position of maxillary anterior teeth against the lower lip?

   1. AS and Z sounds
   2. BT and D sounds
   3. CM and B sounds
   4. DF and V sounds
   Show answer and explanation▾

   Answer: D. F and V sounds

   F and V are labiodental sounds where the maxillary incisal edges should lightly contact the wet-dry line of the lower lip. S sounds are mainly used to assess the closest speaking space and vertical dimension.

2. Question 2Dental materials and laboratory procedureshard

   For a durable metal-ceramic restoration, how should the coefficient of thermal expansion of the alloy relate to that of the porcelain?

   1. AMuch lower, placing porcelain in tension
   2. BSlightly higher, placing porcelain in compression
   3. CExactly equal to eliminate residual stress
   4. DIrrelevant, as bonding is purely mechanical
   Show answer and explanation▾

   Answer: B. Slightly higher, placing porcelain in compression

   An alloy with a slightly higher coefficient contracts more on cooling, leaving the porcelain under residual compression, which it resists well. Porcelain is weak in tension, and the bond relies largely on the oxide layer, not only mechanical retention.

3. Question 3Dental materials and laboratory proceduresmedium

   Why should casts be poured promptly from a condensation silicone impression?

   1. AEthanol by-product evaporates, causing shrinkage
   2. BWater absorption causes swelling
   3. CHydrogen gas release causes bubbles
   4. DSulphur by-product causes surface softening
   Show answer and explanation▾

   Answer: A. Ethanol by-product evaporates, causing shrinkage

   Condensation silicones release ethanol during setting, and its evaporation causes ongoing shrinkage, so casts should be poured soon. Hydrogen release occurs with some addition silicones and is managed by delayed pouring or palladium scavengers.

4. Question 4Dental materials and laboratory proceduresmedium

   A heat-cured acrylic denture shows internal porosity confined to the thickest part of the base. What is the most likely cause?

   1. AInsufficient packing pressure
   2. BExcess polymer in the mix
   3. CCuring temperature raised too rapidly
   4. DToo long a bench cooling time
   Show answer and explanation▾

   Answer: C. Curing temperature raised too rapidly

   Rapid heating raises the temperature in thick sections above the boiling point of monomer (about 100.8 degrees C), causing gaseous porosity in the bulk of the base. Inadequate packing pressure causes more widespread, irregular porosity.

5. Question 5Infection control, ethics and patient safetyeasy

   An alginate impression has just been removed from a patient's mouth. What is the correct infection control step before sending it to the laboratory?

   1. ASeal it dry in a bag and send it without treatment
   2. BAutoclave it at 134 degrees C before dispatch
   3. CSoak it in tap water for one hour before dispatch
   4. DRinse, then disinfect with a compatible disinfectant
   Show answer and explanation▾

   Answer: D. Rinse, then disinfect with a compatible disinfectant

   Impressions should be rinsed to remove saliva and blood and then disinfected with a disinfectant compatible with the material, following the manufacturer's contact time. Heat sterilisation destroys alginate, and prolonged immersion causes distortion.

6. Question 6Diagnosis, treatment planning and occlusionmedium

   In a mutually protected occlusion in a dentate patient, which statement is correct?

   1. APosterior teeth contact on both sides during excursions
   2. BAll teeth contact evenly in lateral excursions
   3. CCanines are kept out of contact in all movements
   4. DAnterior teeth disclude the posterior teeth in excursions
   Show answer and explanation▾

   Answer: D. Anterior teeth disclude the posterior teeth in excursions

   In mutually protected occlusion, posterior teeth support the bite in maximum intercuspation and anterior teeth (canine and incisor guidance) disclude the posterior teeth in excursions. Bilateral posterior contact in excursions describes balanced occlusion used in complete dentures.

7. Question 7Maxillofacial prosthetics and temporomandibular disordershard

   A patient after a stroke has a soft palate of normal length but poor movement, causing hypernasal speech. Which prosthesis is most appropriate?

   1. ASpeech bulb obturator
   2. BPalatal lift prosthesis
   3. CComplete denture with thick palate
   4. DNasal stent
   Show answer and explanation▾

   Answer: B. Palatal lift prosthesis

   Velopharyngeal incompetence with adequate tissue but poor movement is managed with a palatal lift that elevates the soft palate. A speech bulb fills a tissue deficiency, as in insufficiency after cleft or surgical loss.

8. Question 8Removable partial dentureseasy

   A mandibular partial denture is planned. The distance from the gingival margin to the floor of the mouth is 5 mm. Which major connector is indicated?

   1. ALingual plate
   2. BLingual bar
   3. CSublingual bar
   4. DLabial bar
   Show answer and explanation▾

   Answer: A. Lingual plate

   A lingual bar needs adequate vertical space (commonly about 8 mm) for the bar and clearance from the gingival margin. With limited depth, a lingual plate is indicated.

9. Question 9Fixed prosthodonticsmedium

   When preparing a post space in a root-filled tooth, how much apical gutta-percha should be retained?

   1. A1 mm
   2. B10 mm
   3. C4 to 5 mm
   4. DNone if the post is cemented
   Show answer and explanation▾

   Answer: C. 4 to 5 mm

   Retaining about 4 to 5 mm of apical gutta-percha maintains the apical seal while allowing an adequate post length. Leaving less risks leakage and periapical disease.

10. Question 10Implant prosthodonticsmedium

    Which occlusal principle is recommended for a single posterior implant crown?

    1. ANarrow occlusal table and reduced cusp inclination
    2. BHeavy contacts to stimulate bone
    3. CWide occlusal table to spread load
    4. DGroup function contacts in all excursions
    Show answer and explanation▾

    Answer: A. Narrow occlusal table and reduced cusp inclination

    Implants lack a periodontal ligament, so implant-protected occlusion reduces lateral loads through a narrower occlusal table, shallow cusps and light contacts. Heavy or wide contacts increase bending forces on the implant.

11. Question 11Infection control, ethics and patient safetymedium

    A 30-year-old with healthy, sound teeth requests 20 full-coverage zirconia crowns to whiten her smile. What is the most appropriate response?

    1. AExplain risks and offer less invasive options such as whitening
    2. BProceed, as the patient has requested it
    3. CPrepare the teeth but advise against it in writing
    4. DRefer to a colleague who will do the crowns
    Show answer and explanation▾

    Answer: A. Explain risks and offer less invasive options such as whitening

    Extensive preparation of sound teeth carries risks of pulp damage and long-term failure, and the clinician should explain these and offer conservative alternatives. The duty to act in the patient's best interest means a clinician may decline unnecessary invasive treatment.

12. Question 12Maxillofacial prosthetics and temporomandibular disordersmedium

    A patient is to undergo partial maxillectomy. When is the definitive obturator usually made?

    1. AAt the time of the resection, in the operating room
    2. BOne week after surgery, when the packing is removed
    3. CBefore surgery, from preoperative casts of the maxilla
    4. DAfter healing and tissue stability, often 3 to 6 months
    Show answer and explanation▾

    Answer: D. After healing and tissue stability, often 3 to 6 months

    A surgical obturator is placed at surgery, an interim obturator follows during healing, and a definitive obturator is made once tissues have healed and stabilised, usually after several months. Early definitive prostheses fit poorly as the defect changes.

13. Question 13Removable partial denturesmedium

    A patient is missing maxillary right first and second molars and the left first premolar. Third molars are absent and will not be replaced. All other teeth are present. What is the Kennedy classification?

    1. AClass I, modification 1
    2. BClass III, modification 1
    3. CClass IV
    4. DClass II, modification 1
    Show answer and explanation▾

    Answer: D. Class II, modification 1

    The most posterior edentulous area determines the class: a unilateral free-end saddle makes this Class II, and the additional bounded space is modification 1. Class I would need bilateral free-end saddles.

14. Question 14Removable partial denturesmedium

    In the RPI clasp system on the terminal abutment of a distal extension partial denture, where is the occlusal rest placed?

    1. AOn the distal of the abutment
    2. BOn the buccal surface of the abutment
    3. COn the cingulum of the canine only
    4. DOn the mesial of the abutment
    Show answer and explanation▾

    Answer: D. On the mesial of the abutment

    The RPI system uses a mesial rest, distal proximal plate and buccal I-bar, so that the clasp disengages when the saddle is loaded, reducing torque on the abutment. A distal rest would tip the abutment distally.

15. Question 15Removable partial denturesmedium

    Where should an indirect retainer be placed for a mandibular Kennedy Class I partial denture?

    1. ADirectly on the fulcrum line
    2. BDistal to the fulcrum line
    3. CAs far anterior to the fulcrum line as possible
    4. DOn the residual ridge under the saddle
    Show answer and explanation▾

    Answer: C. As far anterior to the fulcrum line as possible

    An indirect retainer resists rotation of the distal extension away from the tissues about the fulcrum line, and its effectiveness increases with distance anterior to that line. A rest on the fulcrum line gives no leverage.

Last reviewed September 2026. Questions are original and written to the published exam blueprint; they are not taken from any real paper.