DHA Restorative Dentistry exam questions

6 worked Restorative Dentistry 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 · Aesthetic Dentistry

   A patient is supplied with 10% carbamide peroxide gel for night-guard vital bleaching. What is the approximate equivalent hydrogen peroxide concentration?

   1. A10%
   2. B35%
   3. C6%
   4. D3.5%
   Show answer and explanation

   Correct answer: D. 3.5%

   Carbamide peroxide breaks down into about one-third hydrogen peroxide, so 10% carbamide peroxide releases approximately 3.5% hydrogen peroxide. 35% hydrogen peroxide is used for in-office power bleaching.

   Reference: Haywood VB. Quintessence Int 1992 (nightguard vital bleaching)

2. Question 2 · Dental Materials and Adhesion

   When restoring a deep Class II cavity with conventional resin composite, what is the maximum recommended increment thickness for curing?

   1. AAbout 2 mm
   2. BAbout 4 mm
   3. CAbout 6 mm
   4. DThe full cavity depth
   Show answer and explanation

   Correct answer: A. About 2 mm

   Conventional composites are placed in increments of about 2 mm to ensure adequate light curing and reduce shrinkage stress. Bulk-fill composites allow 4-5 mm increments, but conventional materials cure inadequately at that depth.

   Reference: Sturdevant's Art and Science of Operative Dentistry, 7th ed.

3. Question 3 · Fixed Prosthodontics

   What is the approximate average combined dimension of junctional epithelium and supracrestal connective tissue attachment (formerly biological width)?

   1. A0.5 mm
   2. B4 mm
   3. C6 mm
   4. D2 mm
   Show answer and explanation

   Correct answer: D. 2 mm

   Gargiulo's classic measurements give an average of about 2 mm (0.97 mm epithelial attachment and 1.07 mm connective tissue). Violating this dimension with restoration margins causes chronic inflammation or bone loss.

   Reference: Gargiulo AW et al. J Periodontol 1961; 2017 World Workshop Classification

4. Question 4 · Fixed Prosthodontics

   For a metal-ceramic crown on a mandibular molar with porcelain occlusal coverage, what reduction is recommended on the functional (buccal) cusps?

   1. A0.5 mm
   2. B1.0 mm
   3. C3.5 mm
   4. D2.0 mm
   Show answer and explanation

   Correct answer: D. 2.0 mm

   Functional cusps of a metal-ceramic crown with porcelain occlusal surfaces need about 2.0 mm reduction, and non-functional cusps about 1.5 mm, to provide thickness for metal and porcelain. Under-reduction leads to over-contoured restorations or thin, fracture-prone porcelain.

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

5. Question 5 · Implant Dentistry

   An implant restoration has no baseline records. Probing depth is 7 mm with bleeding and suppuration, and radiographic bone level is 4 mm apical to the most coronal part of the intraosseous implant. What is the diagnosis?

   1. APeri-implant health
   2. BPeri-implant mucositis
   3. CPeri-implantitis
   4. DSoft tissue recession only
   Show answer and explanation

   Correct answer: C. Peri-implantitis

   Without baseline data, peri-implantitis is defined by bleeding and/or suppuration on probing, probing depths of 6 mm or more and bone levels 3 mm or more apical to the most coronal part of the intraosseous implant. Mucositis has bleeding without bone loss beyond initial remodelling.

   Reference: 2017 World Workshop on Periodontal and Peri-Implant Diseases (Berglundh et al.)

6. Question 6 · Occlusion, Tooth Wear and TMD

   During a Basic Erosive Wear Examination, a sextant's most affected surface shows hard tissue loss of more than 50% of the surface area. What score is recorded for that sextant?

   1. AScore 1
   2. BScore 2
   3. CScore 0
   4. DScore 3
   Show answer and explanation

   Correct answer: D. Score 3

   In the BEWE, 0 is no wear, 1 initial loss of surface texture, 2 a distinct defect with hard tissue loss under 50% of the surface, and 3 hard tissue loss of 50% or more. The highest score in each sextant is recorded.

   Reference: Bartlett D et al. Clin Oral Investig 2008 (BEWE)