CCE Preliminary & Diagnostic Work Up 5 — Questions and Answers
Question 1: When assessing a patient's smile for ceramic restoration planning, what is the significance of the 'commissure line'?
- It indicates the midpoint of the palate
- It helps determine the esthetic width of the smile and how many teeth should be visible (Correct answer)
- It marks the attachment of the frenum
- It identifies the location of the infraorbital foramen
Correct answer: It helps determine the esthetic width of the smile and how many teeth should be visible
The commissure line drawn between the corners of the mouth helps the ceramist determine how many teeth will be visible in a full smile and guides arch width design.
Question 2: In the preliminary work-up, which of the following best describes 'occlusal plane analysis'?
- Measuring the thickness of enamel with a caliper
- Evaluating the orientation of the biting surface relative to a reference plane such as the ala-tragus line (Correct answer)
- Determining the VDO using a Willis gauge
- Assessing caries depth on radiographs
Correct answer: Evaluating the orientation of the biting surface relative to a reference plane such as the ala-tragus line
Occlusal plane analysis compares the existing or planned occlusal plane to facial reference planes to ensure the ceramic restorations will appear level and harmonious.
Question 3: A patient scheduled for ceramic crown restorations is found to have active periodontal disease during the preliminary work-up. What is the appropriate action?
- Proceed with impressions immediately to avoid delaying treatment
- Complete periodontal therapy and achieve stability before fabricating any ceramic restorations (Correct answer)
- Place temporary restorations and monitor for six months
- Adjust ceramic margin placement to compensate for diseased tissue
Correct answer: Complete periodontal therapy and achieve stability before fabricating any ceramic restorations
Active periodontal disease must be treated and tissue must be stable before ceramic restorations are placed, as inflamed tissue levels will change after treatment.
Question 4: During a diagnostic evaluation for ceramic veneers, the patient shows evidence of gastric acid erosion on lingual tooth surfaces. This finding suggests the ceramist should:
- Increase veneer thickness on the labial surface only
- Advise the restorative team to coordinate with medical care to control acid exposure before and after restoration (Correct answer)
- Use a more translucent ceramic to compensate for enamel loss
- Place restorations on the lingual surfaces instead
Correct answer: Advise the restorative team to coordinate with medical care to control acid exposure before and after restoration
Acid erosion from gastric reflux will continue to degrade tooth structure and restoration margins unless the underlying medical condition is managed alongside dental treatment.
Question 5: What is the primary purpose of a 'preliminary impression' versus a 'final impression' in the context of diagnostic work-up?
- Preliminary impressions are taken with irreversible hydrocolloid to make study casts for diagnosis and treatment planning, not for fabricating final restorations (Correct answer)
- Preliminary impressions are taken with PVS for higher accuracy
- Preliminary impressions record the bite registration only
- There is no difference; both are used for final restoration fabrication
Correct answer: Preliminary impressions are taken with irreversible hydrocolloid to make study casts for diagnosis and treatment planning, not for fabricating final restorations
Preliminary (study) impressions, typically taken with alginate, are used to create diagnostic casts for analysis and planning, while final impressions use more accurate elastomeric materials for restoration fabrication.
Question 6: When the ceramist evaluates pre-treatment photographs and notices asymmetric gingival margins, the recommended first step is to:
- Design the wax-up to mask the asymmetry with longer teeth on one side
- Flag the discrepancy for the restorative dentist to determine if tissue recontouring is indicated before ceramic fabrication (Correct answer)
- Select a darker shade to minimize the visual impact of uneven margins
- Proceed normally since minor asymmetries are acceptable
Correct answer: Flag the discrepancy for the restorative dentist to determine if tissue recontouring is indicated before ceramic fabrication
Gingival asymmetry is best resolved at the tissue level through clinical procedures rather than compensated for in ceramic design, and must be discussed with the treating dentist.
Question 7: In a ceramic reconstruction case, which finding on the diagnostic casts would most indicate the need for an anterior deprogrammer before mounting in centric relation?
- Presence of ceramic restorations on posterior teeth
- A significant discrepancy between the patient's habitual bite and the CR position, causing muscle tension (Correct answer)
- Missing third molars on both sides
- Crowding of the mandibular anterior teeth
Correct answer: A significant discrepancy between the patient's habitual bite and the CR position, causing muscle tension
When habitual occlusion differs substantially from centric relation, an anterior deprogrammer relaxes the muscles of mastication so that a true CR record can be captured for accurate cast mounting.
CCE Preliminary & Diagnostic Work Up 5
When assessing a patient's smile for ceramic restoration planning, what is the significance of the 'commissure line'?