Cobalt Chrome II: Main Exam, 11 December 2018

1.

1. a) Define surveying in prosthodontics. (10 marks)
   Model answer

   • Surveying in prosthodontics
   • Definition: Surveying is the systematic measurement and recording of the spatial relationships of the teeth, jaws, and occlusion to guide the design and fabrication of prostheses.
2. b) List five types of model surveyors. (5 marks)
   Model answer

   • Types of model surveyors
   • Manual surveyor
   • Electronic surveyor
   • Digital surveyor
   • Hybrid surveyor
   • Custom surveyor
   • More answers: other specialized surveyors such as intraoral and intra‑maxillary surveyors.
3. c) Outline four steps involved in design transfer to the master cost. (4 marks)
   Model answer

   • Design transfer to the master cast
   • Step 1: Record the master cast on the articulator.
   • Step 2: Transfer the occlusal scheme from the articulator to the cast.
   • Step 3: Adjust the teeth arrangement on the cast accordingly.
   • Step 4: Verify the final arrangement against the design specifications.
4. d) Outline four factors which must be analyzed during surveying. (4 marks)
   Model answer

   • Factors to analyze during surveying
   • Jaw relationship
   • Occlusal vertical dimension
   • Incisal guidance
   • Bite registration accuracy
5. e) Describe how to determine path of insertion of a dentures. (5 marks)
6. f) Explain four general principles of spacing a wax pattern. (8 marks)
   Model answer

   • Principle 1: Ensure the wax pattern is fully supported by the die to prevent distortion.
   • Principle 2: Maintain a uniform thickness of wax to avoid uneven shrinkage during processing.
   • Principle 3: Keep the pattern free of voids and gaps; use proper packing to eliminate porosity.
   • Principle 4: Verify that the pattern’s contours are accurate by checking against the master cast before final processing.
7. g) Enumerate three tools used with a dental surveyor. (3 marks)

2. Describe the procedures of fabricating a metallic framework upto casting after receiving primary impressions. (20 marks)

3. Describe the following during fabrication of metallic removal dentures: i) Sand blasting ii) Electropolishing INSTRUCTIONS: ANSWER ALL QUESTIONS IN SECTION A (COMPULSORY) AND ANY OTHER TWO QUESTIONS IN SECTION B (10 marks)

5. With aid of a diagram describe a mechanical dental surveyor with a cast holder. (20 marks)

6. Describe the following during fabrication of metallic removal dentures: iii) Sand blasting iv) Electropolishing (10 marks)