CDC Quality Control & Industry Standards 2 — Questions and Answers
Question 1: Which ISO standard specifically governs ceramic materials used in dentistry?
- ISO 6872 (Correct answer)
- ISO 9001
- ISO 13485
- ISO 14971
Correct answer: ISO 6872
ISO 6872 specifies requirements and test methods for ceramic materials used in restorative and prosthetic dentistry.
Question 2: During incoming inspection of dental porcelain, which defect would most critically warrant rejection of a batch?
- Slight variation in lot number labeling
- Crystalline inclusions visible under magnification (Correct answer)
- Minor color deviation within shade tolerance
- Packaging with minor cosmetic damage
Correct answer: Crystalline inclusions visible under magnification
Crystalline inclusions in dental porcelain indicate contamination or improper manufacturing and can compromise restoration strength and esthetics.
Question 3: What does the term 'process validation' mean in a dental laboratory quality system?
- Verifying that instruments are calibrated annually
- Documenting that a process consistently produces results meeting specifications (Correct answer)
- Confirming that technicians have current certifications
- Reviewing customer feedback on completed restorations
Correct answer: Documenting that a process consistently produces results meeting specifications
Process validation establishes documented evidence that a dental laboratory process will consistently produce a product meeting its predetermined specifications.
Question 4: Under FDA regulations, a dental laboratory that fabricates custom ceramic restorations is classified as a:
- Medical device manufacturer requiring a 510(k)
- Device establishment subject to registration requirements (Correct answer)
- Exempt entity with no regulatory obligations
- Clinical laboratory under CLIA oversight
Correct answer: Device establishment subject to registration requirements
Dental laboratories that fabricate custom devices are typically required to register as device establishments with the FDA.
Question 5: A shade guide used for quality control verification should be replaced when:
- A new technician joins the laboratory
- Tabs show visible wear, fading, or damage affecting color accuracy (Correct answer)
- The laboratory undergoes accreditation review
- Six months have passed since purchase regardless of condition
Correct answer: Tabs show visible wear, fading, or damage affecting color accuracy
Worn or faded shade tabs produce inaccurate color comparisons, making replacement necessary when physical condition compromises reliability.
Question 6: In a dental laboratory's corrective action process, the 'root cause analysis' step is critical because:
- It satisfies insurance documentation requirements
- Identifying the true cause prevents recurrence of the nonconformance (Correct answer)
- It provides data for technician performance reviews
- It determines the financial cost of the defect
Correct answer: Identifying the true cause prevents recurrence of the nonconformance
Root cause analysis identifies why a defect occurred so that effective corrective actions can eliminate the cause and prevent future occurrences.
Question 7: Which measurement tool is most appropriate for verifying the marginal fit tolerance of a ceramic crown in a quality control check?
- Digital caliper
- Micrometer screw gauge
- Calibrated explorer probe
- Optical comparator or digital microscope (Correct answer)
Correct answer: Optical comparator or digital microscope
An optical comparator or digital microscope provides magnified, measurable assessment of marginal gap dimensions with the accuracy needed for crown fit verification.
CDC Quality Control & Industry Standards 2
Which ISO standard specifically governs ceramic materials used in dentistry?