DANB CDA: earning the Certified Dental Assistant credential

A right-handed operator is preparing an MO on #3. The assistant should place the HVE tip:

Pick the option you would mark on test day. The choice stays fixed, and every option then explains itself.

1. Directly over the occlusal of #3

   A tip held over the occlusal surface sits between the bur and the operator's eyes, blocking both the view and the light.
2. Lingual, slightly distal to #3

   For a right-handed operator the assistant sits on the patient's left, so on the maxillary right the palatal side is the near side; the tip goes just distal to the tooth being cut, where it catches the spray.
3. Lingual, slightly mesial to #3

   The palatal side is right, but standard placement is slightly distal to the tooth being prepared; moving the tip mesial shifts it away from where the spray collects.
4. Buccal, slightly distal to #3

   Buccal placement is the rule for the patient's left side; on #3 the buccal surface faces the operator, so the tip would cross the patient and crowd the operator's field.

An office connects an independent water reservoir to the dental unit. On its own, the reservoir:

1. Keeps water under 500 CFU/mL

   500 CFU/mL is the target for treated unit water, but a reservoir alone does not reach it; without a cleaner or chemical treatment counts climb well above that level.
2. Makes water sterile for surgery

   Reservoir water is not sterile; surgical procedures call for sterile solution delivered through a sterile system.
3. Does not stop waterline biofilm

   A separate bottle only changes the water source; the narrow tubing still grows biofilm, so the system still needs a treatment product and regular monitoring.
4. Does not require water testing

   A reservoir gives no information about water quality, so periodic testing is still how the office confirms the water meets the standard.

After lubricating a high-speed handpiece that requires it, the assistant should, before packaging it for sterilization:

1. Place it in the ultrasonic

   Most manufacturers prohibit ultrasonic cleaning of handpieces because it damages bearings and optics; cleaning was already done before lubrication.
2. Wipe it with disinfectant only

   Wiping the outside does nothing about the surplus lubricant inside the head, and disinfection never replaces heat sterilization of a handpiece.
3. Seal it wet in the pouch

   Packaging a handpiece with oil and moisture still on it traps residue in the pouch and can keep steam from reaching every surface.
4. Run it to expel excess oil

   Running the handpiece briefly after lubrication pushes out surplus oil that would otherwise bake onto the turbine and soil the package during sterilization.

An assistant has a herpetic whitlow on her finger. According to CDC, she should:

1. Be kept from patient contact

   CDC's personnel-health guidance restricts a worker with herpetic whitlow from patient contact and from handling the patient's environment until the lesion has healed.
2. Double-glove and work as usual

   Doubling gloves is the protective reflex many staff reach for, but glove tears and leaks make it no substitute for keeping the infected finger away from patients.
3. Bandage it and keep working

   Bandaging treats the whitlow like a minor cut, but the lesion sheds infectious virus, so a dressing does not make patient care safe.
4. Wear a finger cot under the glove

   A finger cot covers the lesion yet leaves the herpes virus one tear away from a patient; a covering does not replace work restriction.