Mixed Deck — All DANB Topics Flashcards

After taking an alginate impression, the dental assistant should immediately rinse it under cool running water and then disinfect it. What is the primary reason for wrapping the disinfected impression in a damp paper towel and placing it in a sealed bag before pouring?

Answer: To prevent distortion from syneresis or imbibition.

Alginate is a hydrocolloid material, meaning its primary component is water. It is dimensionally unstable and susceptible to changes if not handled correctly. Wrapping it in a damp towel in a sealed bag creates a 100% humidity environment, which prevents water loss (syneresis) or water gain (imbibition), either of which would cause the impression to distort. The impression should be poured as soon as possible, ideally within 10-15 minutes, to ensure accuracy.

Which instrument is used to carve occlusal anatomy in amalgam restorations?

Answer: Discoid-cleoid carver

The discoid-cleoid carver is a specialized dental instrument used to precisely shape and refine the occlusal (biting) surface of amalgam restorations. Its discoid end is spoon-shaped for carving broad areas, while the cleoid end is pointed for creating fine anatomical details like grooves and cusps. This helps restore the tooth's natural form and function.

The most common irrigant used to disinfect the canal system during root canal therapy is:

Answer: Sodium hypochlorite

Sodium hypochlorite (NaOCl), which is essentially household bleach in a diluted and purified form, is the most widely used irrigant. It is highly effective at dissolving necrotic tissue and killing bacteria within the complex root canal system.

Which type of cement is most commonly used to permanently seat a porcelain-fused-to-metal (PFM) crown?

Answer: Resin cement

Resin cements are preferred for PFM crowns because they provide strong adhesion, excellent marginal seal, and minimal film thickness.

A carious lesion located on the proximal surface of a posterior tooth is classified as:

Answer: Class II

G.V. Black's Classification system categorizes caries based on location. A Class II lesion involves the proximal (mesial or distal) surfaces of premolars and molars. These restorations often require an occlusal component for access.

Topical anesthetics are applied before injections primarily to:

Answer: Numb surface tissue and reduce injection discomfort

Topical anesthetics numb the superficial mucosal tissue before the injection, reducing the discomfort the patient experiences from needle penetration.

Which drug is used during a dental emergency to relieve chest pain caused by angina?

Answer: Nitroglycerin

Nitroglycerin is a coronary vasodilator used sublingually to relieve angina by increasing blood flow to the heart muscle.

What is the purpose of using a rubber dam during endodontic treatment?

Answer: To prevent contamination and protect the patient's airway

A rubber dam is essential in endodontics for several reasons. It isolates the tooth from the oral environment, preventing contamination from saliva and bacteria, and it protects the patient from aspirating or swallowing small instruments, irrigants, or debris.

Which periodontal finding is considered within NORMAL limits?

Answer: 2 mm probing depth with no bleeding on probing

A probing depth of 1–3 mm with no bleeding on probing indicates a healthy gingival sulcus and normal periodontal attachment.

What is the purpose of a bite registration in a crown and bridge procedure?

Answer: To record the occlusal relationship between upper and lower teeth

A bite registration records the exact opposing relationship of the arches so the dental laboratory can fabricate the crown with correct occlusal contacts.

Which of the following helps reduce patient radiation exposure?

Answer: Using a rectangular collimator

A rectangular collimator significantly reduces patient radiation exposure by restricting the x-ray beam to the exact size and shape of the film or sensor. Unlike a round collimator, which produces a larger, circular beam, the rectangular shape minimizes the irradiated area. This reduces the amount of unnecessary tissue exposure, adhering to the ALARA principle.

What concentration of epinephrine is most commonly found in standard dental local anesthetic cartridges?

Answer: 1:100,000

The 1:100,000 concentration of epinephrine is standard in most dental anesthetic carpules, providing effective vasoconstriction while minimizing cardiovascular side effects.

Which cement is commonly used for permanent crowns?

Answer: Glass ionomer

Glass ionomer cement is frequently used for permanent cementation of crowns, bridges, and other indirect restorations due to its chemical adhesion to tooth structure and metal, as well as its fluoride-releasing properties. Its biocompatibility and low solubility make it a reliable choice for long-term restorations. It also helps prevent secondary caries.

A carious lesion on the gingival third of the facial surface of tooth #6 would be classified as:

Answer: Class V

A Class V lesion is located on the gingival (cervical) third of the facial or lingual surfaces of any tooth, whether anterior or posterior. Tooth #6 is the maxillary right canine.

In four-handed dentistry, when assisting a right-handed operator, the assistant's zone of activity is located between:

Answer: 2 o'clock and 4 o'clock

For a right-handed operator, the assistant's zone is from 2 to 4 o'clock. This positioning allows the assistant to easily pass instruments, manage suction, and have a clear view of the operating field without interfering with the operator.

What is a 'pontic' in a fixed dental bridge?

Answer: The artificial tooth that replaces the missing tooth

The pontic is the artificial tooth component of a bridge that spans the edentulous space, supported by the abutment crowns on either side.

If a patient begins to have a grand mal seizure in the dental chair, the primary responsibility of the dental team is to:

Answer: Protect the patient from injury

During a seizure, the patient is at risk of injury from the convulsive movements. The dental team's priority is to prevent injury by clearing the area of sharp instruments and gently guiding the patient to prevent falls, without forcefully restraining them. Maintaining the airway is also critical.

What is considered the normal range for a healthy adult's resting pulse rate?

Answer: 60-100 beats per minute

A normal resting heart rate for adults ranges from 60 to 100 beats per minute (BPM). A rate below 60 BPM is bradycardia, and a rate above 100 BPM is tachycardia, both of which may warrant further medical evaluation.

During crown preparation, the dental assistant's primary chairside role is to:

Answer: Retract tissue, evacuate fluids, and transfer instruments to the dentist

The dental assistant supports the operator during crown preparation by maintaining visibility through tissue retraction, evacuation, and efficient instrument transfer.

Which of the following is an appropriate dietary recommendation for a patient on the day of a surgical extraction?

Answer: Yogurt, pudding, and lukewarm soup

A soft, non-chew diet is recommended for the first 24 hours after surgery. Foods like yogurt, smoothies (without a straw), pudding, and lukewarm soups provide necessary nutrition without requiring chewing or risking damage to the surgical site.