DANB NELDA cheat sheet

ALARA principle: keep occupational exposure As Low As Reasonably Achievable using time, distance, and shielding; radiation intensity falls with the inverse square of distance from the source.

Maximum permissible occupational dose (whole body) is 50 mSv (5 rem) per year; the general public limit is 1 mSv (0.1 rem) per year.

A dosimeter badge is worn at collar level outside the apron; a second badge, if used, is worn under the apron at waist level and the two readings are not simply added.

Lead apron and thyroid collar must be at least 0.25 mm lead equivalent; aprons are inspected radiographically or fluoroscopically for cracks.

Digital sensors are more sensitive than film, so exposure times are reduced; receptor holders and beam alignment devices replace finger stabilization.

Collimation to the size of the receptor and a rectangular PID reduce the volume of tissue irradiated and scatter.

Operator must stand at least 6 feet (2 m) from the patient and out of the primary beam during exposure; never hold the receptor or tubehead in the beam.

Scatter radiation is the principal occupational hazard in dental radiography; the primary beam is attenuated by the patient's tissues.

Chain of infection requires a pathogen, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host; breaking any link prevents transmission.

Standard precautions apply to all patients regardless of diagnosis; they include hand hygiene, gloves, masks, eye protection, and gowns when splash is anticipated.

Hand hygiene with soap and water or alcohol-based rub is performed before and after glove use and after contact with contaminated items; artificial nails and chipped polish are avoided.

Critical items (e.g., surgical instruments, scalers) penetrate tissue and must be sterilized; semicritical items contact mucosa and require at least high-level disinfection; noncritical items touch intact skin.

Steam autoclave cycles typically run at 121°C (250°F) for 15–30 minutes or 132°C (270°F) for 3–4 minutes; biological spore testing monitors sterilization efficacy.

A biological indicator using Geobacillus stearothermophilus spores is the standard weekly (or per policy) check for steam sterilizers.

Surface barriers or EPA-registered hospital disinfectant with tuberculocidal claim are used for operatory surfaces; blood and saliva are treated as potentially infectious.

Sharps are placed in puncture-resistant, labeled containers; needles are never recapped by hand (use scoop technique or a recapping device).

Four-handed dentistry positions the operator and assistant so that transfer zones and the patient's oral cavity are reached without crossing the patient's face or the operator's field.

Instrument transfer: assistant passes the instrument handle into the operator's palm while retrieving the used instrument in the same motion, keeping the working end oriented toward the tooth.

The dental assistant's expanded functions are defined by state dental practice acts; typical allowable duties include suctioning, retraction, mixing materials, and passing instruments.

Universal/ISO tooth numbering: permanent teeth 1–32 (1 = maxillary right third molar); primary teeth A–T; FDI uses two digits (quadrant + tooth).

A matrix band and retainer restore proximal contour and contact when a class II cavity is prepared; wedges stabilize the band and protect the adjacent tooth.

Common dental cements: zinc phosphate (strong, acidic), glass ionomer (fluoride release, bonds to tooth), zinc oxide-eugenol (sedative, palliative for pulp).

Vital signs: normal adult blood pressure ~120/80 mmHg, pulse 60–100 bpm, respirations 12–20/min, temperature ~37°C (98.6°F).

Medical emergency basics: syncope - supine position and oxygen; hypoglycemia - oral glucose if conscious; angina - nitroglycerin as prescribed; anaphylaxis - epinephrine.