DHA Prosthodontics exam questions

6 worked Prosthodontics practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Complete dentures

   A patient has a mobile, fibrous anterior maxillary ridge. What impression approach best avoids distorting this tissue?

   1. AHigh-viscosity material under heavy pressure
   2. BClosed-mouth impression with heavy bite force
   3. CSelective pressure with a window over the flabby area
   4. DSurgical excision before any impression
   Show answer and explanation

   Correct answer: C. Selective pressure with a window over the flabby area

   A window or selective pressure technique records the flabby tissue in an undisplaced state, often with a low-viscosity material, while recording the rest of the denture-bearing area normally. Heavy pressure displaces the tissue, which rebounds and unseats the denture.

   Reference: Zarb's Prosthodontic Treatment for Edentulous Patients, 13th ed.

2. Question 2 · Diagnosis, treatment planning and occlusion

   Which description best defines centric relation?

   1. AThe position of maximum intercuspation of the teeth
   2. BThe mandibular position when the patient is at rest
   3. CThe jaw position determined by the first tooth contact in closure
   4. DA jaw relationship with condyles seated anterosuperiorly, independent of tooth contact
   Show answer and explanation

   Correct answer: D. A jaw relationship with condyles seated anterosuperiorly, independent of tooth contact

   Centric relation is a reproducible maxillomandibular relationship with the condyles in the anterosuperior position against the articular eminences, independent of tooth contact. Maximum intercuspation is determined by the teeth and may differ from centric relation.

   Reference: The Glossary of Prosthodontic Terms, 10th ed.

3. Question 3 · Diagnosis, treatment planning and occlusion

   What is the main purpose of a facebow record in fixed or removable prosthodontics?

   1. ATo record the vertical dimension of occlusion
   2. BTo record lateral condylar guidance
   3. CTo transfer the maxillary cast's relation to the hinge axis
   4. DTo measure the interocclusal rest space
   Show answer and explanation

   Correct answer: C. To transfer the maxillary cast's relation to the hinge axis

   A facebow relates the maxillary arch to the condylar hinge axis so the cast is mounted correctly on the articulator, making arcs of closure more accurate. Condylar guidance is set from protrusive or lateral records.

   Reference: The Glossary of Prosthodontic Terms, 10th ed.

4. Question 4 · Fixed prosthodontics

   A five-unit bridge from canine to second molar has the second premolar as a pier abutment. Where is the non-rigid key and keyway connector usually placed?

   1. AKeyway on the distal of the pier abutment retainer
   2. BKeyway on the mesial of the canine retainer
   3. CKey on the distal of the molar retainer
   4. DA rigid connector at every joint
   Show answer and explanation

   Correct answer: A. Keyway on the distal of the pier abutment retainer

   In a pier abutment situation, a non-rigid connector reduces stress concentration; the keyway is usually placed on the distal of the pier retainer with the key on the mesial of the distal pontic, so mesial forces seat the key. A fully rigid design can lead to loosening of a terminal retainer.

   Reference: Shillingburg's Fundamentals of Fixed Prosthodontics, 4th ed.

5. Question 5 · Fixed prosthodontics

   Which surface treatment is recommended before adhesive cementation of a zirconia crown?

   1. AAir abrasion with alumina and an MDP-containing primer
   2. BHydrofluoric acid etching and silane
   3. CPhosphoric acid etching alone
   4. DNo treatment; zirconia bonds like glass ceramic
   Show answer and explanation

   Correct answer: A. Air abrasion with alumina and an MDP-containing primer

   Zirconia contains no glass phase, so hydrofluoric acid etching is ineffective; low-pressure alumina air abrasion and an MDP-containing primer give a durable bond. Hydrofluoric acid and silane are used for glass ceramics such as lithium disilicate.

   Reference: Rosenstiel's Contemporary Fixed Prosthodontics, 5th ed.

6. Question 6 · Implant prosthodontics

   Two adjacent implants are planned to replace maxillary central and lateral incisors. What minimum distance between the implants is recommended to preserve interimplant crestal bone?

   1. A1 mm
   2. B1.5 mm
   3. C6 mm
   4. D3 mm
   Show answer and explanation

   Correct answer: D. 3 mm

   An interimplant distance of at least 3 mm reduces crestal bone loss and helps preserve the papilla, while about 1.5 mm is advised between an implant and a natural tooth. Less than 3 mm between implants was linked to greater bone loss.

   Reference: Tarnow et al., Journal of Periodontology 2000