DANB CDA cheat sheet

ALARA principle: keep occupational and patient exposure As Low As Reasonably Achievable through time, distance, and shielding; distance is the most effective operator control because exposure falls with the inverse square of distance.

Inverse square law: I1/I2 = (D2/D1)^2 - doubling the distance from the source reduces intensity to one quarter.

Maximum permissible occupational dose is 50 mSv (5 rem) per year; the public limit is 1 mSv (0.1 rem) per year. Cumulative lifetime allowance formula: age in years × 10 mSv (1 rem).

Personnel monitoring uses film badges, TLDs, or OSL dosimeters worn at collar level outside the lead apron; a second badge worn under the apron is used for declared pregnant staff or high-dose workloads.

Occupational radiation badge reports are recorded as shallow dose (skin, 0.07 mm depth) and deep dose (whole body, 1 cm depth); report a badge over-read to the radiation safety officer, not the patient.

Lead apron minimum 0.25 mm lead equivalent for intraoral radiography; thyroid collar is required for all intraoral exposures and for panoramic exposure in children and adults of reproductive age.

Collimation: rectangular PID collimation reduces the exposed tissue area compared with round collimation and lowers patient dose; the PID length (typically 20 cm or 30 cm) affects beam divergence and skin dose.

Digital sensors require less exposure than film (roughly one-third to one-half); the operator must not compensate by increasing exposure time, because overexposure degrades digital image quality without diagnostic benefit.

Hold the image receptor with a positioning device, never the patient's or operator's fingers; do not stabilize the tubehead by hand during exposure. Exposed retake decisions must be based on diagnostic need, not convenience.

Chain of infection: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host - break any link to prevent transmission.

Standard precautions apply to all patients regardless of diagnosis; they include hand hygiene, gloves, eye protection, mask, and safe sharps handling.

Hand hygiene: soap and water when hands are visibly soiled or after contact with blood/body fluids; alcohol-based hand rub for routine decontamination when hands are not visibly soiled (typically 20–30 seconds rub).

Critical items (surgical instruments, scalers, forceps) penetrate tissue and must be sterilized; semicritical items (mirrors, radiographic film holders, impression trays) contact mucosa and require sterilization or high-level disinfection; noncritical items (light handles, chair surfaces) require low-level disinfection.

Spore test (biological indicator) using Geobacillus stearothermophilus for steam and chemical vapor sterilizers; Bacillus atrophaeus for dry heat and ethylene oxide. A positive spore test requires removing the sterilizer from service and retesting.

Sterilizer monitoring: mechanical (gauge, temperature, pressure), chemical (autoclave tape, internal indicators), and biological (spore test) - biological is the most reliable indicator of sterilization.

Surface barriers are preferred over disinfection for items that are difficult to clean; if a barrier is used, it must be replaced between patients, and surfaces under barriers are disinfected at the end of the day.

Sharps safety: do not recap needles by hand (use the one-handed scoop technique or a recapping device); place sharps in a rigid, puncture-resistant, labeled container filled no more than three-quarters full.

Occupational exposure protocol: wash the site with soap and water, report immediately, and follow post-exposure evaluation including source testing and prophylaxis decisions within the timeframe set by the exposure control plan.

Four-handed dentistry: the assistant transfers instruments within the transfer zone (patient's chest area) and maintains the operating field with high-volume evacuation and saliva ejector.

High-volume evacuation (HVE) tip is held near the tooth being treated (within about 1–2 cm of the operative site); the saliva ejector is placed in the lower vestibule and is not a substitute for HVE.

Instrument transfer: pass instruments by the handle end with the working end toward the dentist, using the pen-grip grasp; announce the instrument name and keep a consistent sequence.

Anesthetic setup: short 25-gauge or 27-gauge needle for infiltration, long 25-gauge or 27-gauge for inferior alveolar block; 27-gauge is used for pediatric and for patients needing slower injection.

Common local anesthetics: 2% lidocaine with 1:100,000 epinephrine (1.8 mL cartridge = 36 mg lidocaine, 0.018 mg epinephrine); 4% articaine with 1:100,000 epinephrine; 3% mepivacaine plain (no vasoconstrictor).

Maximum recommended dose: lidocaine 4.4 mg/kg (about 300 mg absolute for a healthy adult); articaine 7 mg/kg; calculate cartridges by dividing total mg by mg per cartridge.

Rubber dam application: punch hole, lubricate, ligate or clamp the anchor tooth, invert the dam margins with floss, and verify seal; the dam isolates the field and protects the airway.

Matrix systems: Tofflemire retainer for posterior Class II restorations; sectional matrix and wedge for tight contacts; wedge holds the band and protects the adjacent tooth.

Amalgam and composite finishing: carve amalgam while it is still workable, then burnish; composite is light-cured in increments (typically 2 mm) and finished with fine grits; avoid contamination of the etched field.

Tooth numbering: Universal system (1–32, starting with the maxillary right third molar as 1); FDI system uses two digits (quadrant 1–4 plus tooth 1–8); Palmer uses quadrant symbols with 1–8.

Primary dentition Universal letters A–J maxillary right to left, K–T mandibular left to right; FDI primary quadrants are 5–8.

Dental charting abbreviations: MOD (mesial-occlusal-distal), DO, MO, PFM (porcelain-fused-to-metal), RCT (root canal therapy), SRP (scaling and root planing), NKA (no known allergies).

Periodontal charting: probing depth 1–3 mm is healthy; 4 mm suggests gingivitis or early attachment loss; 5 mm or more indicates periodontitis and requires further assessment; bleeding on probing indicates active inflammation.

Dental caries process: demineralization by bacterial acids (Streptococcus mutans, Lactobacillus) balanced against remineralization by saliva and fluoride; fluoride promotes remineralization as fluorapatite.

Medical emergency basics: syncope - supine position with legs elevated; hypoglycemia - give oral glucose if conscious; angina - nitroglycerin sublingual, oxygen; anaphylaxis - epinephrine; always activate EMS for unresponsive patients.

Vital signs for adults: blood pressure normal below 120/80 mmHg; pulse 60–100 beats per minute; respiration 12–20 per minute; temperature 36.1–37.2 °C (97–99 °F).

Standard precautions and OSHA recordkeeping: exposure control plan, hepatitis B vaccination offer, annual training, and sharps injury log are required elements of the office safety program.

Dental specialties and scope: endodontics treats pulp and periapical tissue; periodontics treats gingiva and supporting structures; prosthodontics restores missing teeth; oral surgery includes extractions and biopsies; orthodontics corrects malocclusion.