CCE Preliminary & Diagnostic Work Up 3 — Questions and Answers
Question 1: Which of the following best describes the purpose of a diagnostic mock-up applied directly in the patient's mouth?
- To permanently bond ceramic to enamel for testing
- To allow intraoral evaluation of proposed tooth shape and length before any preparation (Correct answer)
- To take a final impression for the laboratory
- To measure centric relation before mounting casts
Correct answer: To allow intraoral evaluation of proposed tooth shape and length before any preparation
An intraoral mock-up uses provisional composite or bisacryl material to preview proposed changes directly on the patient's teeth without altering tooth structure.
Question 2: During the preliminary evaluation, the ceramist notes that a patient's existing PFM crowns have black gingival margins. What does this indicate for planning all-ceramic replacements?
- The patient has periodontal disease requiring surgery before ceramics
- Metal substructure oxidation is telegraphing through; all-ceramic restorations should eliminate this issue (Correct answer)
- The teeth are non-vital and require endodontic retreatment
- Shade B1 should be selected to mask the margins
Correct answer: Metal substructure oxidation is telegraphing through; all-ceramic restorations should eliminate this issue
Black or gray gingival margins on PFM crowns result from metal oxide show-through; replacing them with metal-free all-ceramic restorations removes this esthetic problem.
Question 3: What is the significance of recording centric relation (CR) during the preliminary work-up?
- It establishes the patient's preferred esthetic position
- It provides a reproducible reference position of the condyles to mount casts accurately (Correct answer)
- It records the maximum intercuspation of the existing teeth
- It measures the vertical dimension of rest
Correct answer: It provides a reproducible reference position of the condyles to mount casts accurately
Centric relation is the most reproducible and stable mandibular position and serves as a reliable starting point for mounting diagnostic casts and designing occlusion.
Question 4: A patient presents with multiple failing ceramic restorations that fractured within two years of placement. What preliminary diagnostic step is most important before replacement?
- Selecting a stronger ceramic material immediately
- Identifying the occlusal load or parafunctional habits contributing to failure (Correct answer)
- Increasing wall thickness of new restorations by 0.5mm
- Changing the cement type for rebonding
Correct answer: Identifying the occlusal load or parafunctional habits contributing to failure
Understanding why restorations failed—such as bruxism, heavy occlusal contacts, or inadequate preparation—is essential to prevent recurrence.
Question 5: In the preliminary work-up, the ceramist evaluates the patient's lip line at full smile. A high lip line affects ceramic design primarily because:
- It requires a darker shade to compensate for light reflection
- The gingival margin and cervical third of restorations will be visible and must be esthetically refined (Correct answer)
- It indicates the patient needs crown lengthening
- High lip lines have no bearing on ceramic design
Correct answer: The gingival margin and cervical third of restorations will be visible and must be esthetically refined
A high lip line exposes the gingival margins of anterior restorations during smiling, making precise margin placement and cervical contour critical to the final esthetic result.
Question 6: What does an occlusal analysis during preliminary work-up help the ceramist determine?
- The patient's preference for composite vs. ceramic materials
- Guidance patterns, premature contacts, and occlusal interferences that could stress ceramic restorations (Correct answer)
- The number of assistants needed in the lab
- Whether impressions should be taken with alginate or polyvinyl siloxane
Correct answer: Guidance patterns, premature contacts, and occlusal interferences that could stress ceramic restorations
Occlusal analysis identifies guidance patterns and contacts so ceramic restorations can be designed to function within the patient's occlusal scheme without undue stress.
Question 7: When evaluating tooth proportions in a diagnostic work-up for ceramic veneers, the ideal width-to-length ratio for a maxillary central incisor is approximately:
- 50–55%
- 75–80% (Correct answer)
- 90–95%
- 60–65%
Correct answer: 75–80%
A width-to-length ratio of approximately 75–80% is considered esthetically pleasing for maxillary central incisors in dental ceramic design.
CCE Preliminary & Diagnostic Work Up 3
Which of the following best describes the purpose of a diagnostic mock-up applied directly in the patient's mouth?