Mixed Deck — All CDT Topics Flashcards

Which mandibular incisor typically has a bifurcated root canal system despite appearing to have only one root externally?

Answer: Mandibular central incisor

The mandibular central incisor, although it appears to have a single slender root, frequently has a labiolingual bifurcation of its root canal system.

Type III gold alloy is preferred over Type I for fixed partial dentures primarily because of its:

Answer: Greater hardness and strength to withstand masticatory forces

Type III gold alloys have higher hardness and strength compared to Type I, making them suitable for load-bearing restorations like fixed partial dentures.

Which groove on the mandibular first molar separates the mesiolingual and distolingual cusps?

Answer: Lingual groove

The lingual groove of the mandibular first molar runs between the mesiolingual and distolingual cusps on the lingual surface.

Which material is commonly used for dental impressions?

Answer: Alginate

Alginate is a widely utilized impression material in dentistry due to its ease of use, cost-effectiveness, and ability to capture sufficient detail for many applications. It is an irreversible hydrocolloid that sets quickly, making it ideal for creating study models, orthodontic appliances, and preliminary impressions for dentures. While other materials exist, alginate remains a popular choice for general dental impressions.

What is 'sintering' in the context of zirconia processing?

Answer: High-temperature densification that transforms porous zirconia into a hard, dense ceramic

Sintering fires zirconia at approximately 1,450–1,530°C, driving off porosity and transforming it into its final, hard, dense form.

A technician notices small voids (porosity) throughout a cast metal framework after casting. The most likely cause is:

Answer: Insufficient alloy volume in the crucible

Using too little alloy means insufficient metallostatic pressure to fill the mold completely, leading to shrinkage porosity throughout the casting.

Which practice violates standard infection control protocols in a dental laboratory?

Answer: Touching a phone with contaminated gloves to answer a call

Touching personal items such as phones with contaminated gloves spreads pathogens to non-clinical surfaces and represents a cross-contamination breach of infection control protocol.

What is the coefficient of thermal expansion (CTE), and why is it critical in PFM restorations?

Answer: A measure of how a material expands/contracts with temperature; metal and ceramic CTEs must be compatible

CTE compatibility between metal and porcelain prevents internal stresses that would cause cracking or delamination during cooling.

What is the primary objective of crown & bridge fabrication in Certified Dental Technicians practice?

Answer: Ensuring consistent quality and adherence to professional standards

The primary objective of crown & bridge fabrication is ensuring consistent quality and adherence to professional standards that protect both practitioners and those they serve.

Which milling bur diameter is typically used for final marginal finishing in a 5-axis milling unit?

Answer: 0.6 mm or 1.0 mm diameter bur

Small-diameter burs (0.6–1.0 mm) allow the mill to follow tight marginal curves and produce accurate finish lines.

The term 'embrasure' in dental anatomy refers to which space?

Answer: The V-shaped space that widens from the contact area toward the facial, lingual, or occlusal

An embrasure is the triangular space adjacent to the contact area of two teeth that opens toward the facial, lingual, or occlusal surface.

What defines a cusp-to-fossa occlusal arrangement?

Answer: Each supporting cusp is directed into the opposing central fossa

In cusp-to-fossa occlusion, the supporting cusps are directed into the opposing central fossae, creating stable tripod centric contacts and favorable load distribution along the long axis of teeth.

A laboratory technician receives a scan body scan from a digital workflow. What does the scan body capture in intraoral scanning?

Answer: The three-dimensional position and orientation of the implant

Scan bodies (scan abutments) are precision components placed on implants that allow intraoral scanners to record the implant's exact 3D position and angulation.

Which base metal alloy component is primarily responsible for the natural oxide layer that improves ceramic bonding in PFM restorations?

Answer: Beryllium or tin

Beryllium and tin in base metal alloys form surface oxides during oxidation that chemically bond to porcelain for improved ceramic adhesion.

What is an 'immediate denture' and what is a primary disadvantage of this prosthesis?

Answer: A denture placed immediately after extraction; disadvantage is that post-extraction ridge resorption makes it loose within months

Immediate dentures are placed at the time of extraction but require frequent relines or replacement as the ridge resorbs rapidly in the first 6–12 months.

What does the term 'emergence profile' refer to in CAD design of a crown?

Answer: The contour of the restoration as it exits the gingival margin

Emergence profile describes how the restoration transitions from the subgingival finish line through the gingival tissue.

What is a pantograph used for in dental prosthetics?

Answer: Recording all three-dimensional mandibular movements to program a fully adjustable articulator

A pantograph records the full three-dimensional movements of the mandible in all excursions, providing the data needed to program a fully adjustable articulator.

What is the purpose of 'platform switching' in implant design?

Answer: Using a narrower abutment on a wider implant platform to preserve crestal bone

Platform switching positions the abutment-implant microgap away from the bone crest, which is associated with reduced crestal bone resorption.

What is the primary purpose of a face-bow transfer in dental prosthetics?

Answer: To relate the maxillary cast to the hinge axis of the articulator

A face-bow transfer records the spatial relationship of the maxillary arch to the temporomandibular joint hinge axis so the upper cast can be correctly mounted on the articulator.

When addressing challenges in cad/cam digital dentistry, what approach is most effective?

Answer: Systematic analysis of root causes followed by evidence-based solutions

Systematic root cause analysis with evidence-based solutions addresses problems at their source, preventing recurrence and leading to lasting improvement.