Infection Control
The Infection Control domain tests standard precautions, PPE, hand hygiene, disinfection and sterilization, waterline management, and safe handling of sharps and laboratory items. Questions often ask you to choose the correct processing level for an item or interpret sterilization monitoring.
Standard precautions and PPE
Treat every patient as potentially infectious. Perform hand hygiene before and after patient contact and after glove removal. Don PPE in order-gown, mask, eyewear, gloves-and remove in reverse: gloves first, then eyewear, mask, and gown. Change gloves between patients and when torn; never wash or reuse exam gloves. Replace masks when wet or soiled.
Processing levels
Critical items (forceps, scalers, surgical instruments) penetrate tissue or contact bone: clean, package, and sterilize. Semicritical items (mouth mirrors, condensers, amalgam carriers) contact mucosa but not bone: sterilize or high-level disinfect. Noncritical items (blood pressure cuff, chair) contact intact skin: clean and low-level disinfect. For blood or body-fluid spills, use an EPA-registered hospital disinfectant with a tuberculocidal claim.
Sterilization and monitoring
Steam autoclave: 121°C (250°F) at 15 psi for 15–20 minutes, or 132°C (270°F) for 3–4 minutes. Dry heat: 160°C (320°F) for 2 hours or 170°C (340°F) for 1 hour. Use an internal chemical indicator and do not overload. Monitor with the mechanical gauge, chemical indicator, and biological spore test. Steam uses Geobacillus stearothermophilus; dry heat and ethylene oxide use Bacillus atrophaeus. Test at least weekly and after repairs. A positive spore test means remove the sterilizer from service, repeat the test, recall and reprocess items, and document.
Waterlines, suction, and radiography
Flush dental unit waterlines 20–30 seconds after each patient and at the start of the day; use independent reservoirs and follow manufacturer treatment. Flush suction lines with disinfectant and change traps safely. Cover the tubehead, control panel, and sensor with barriers; disinfect after exposure while wearing gloves.
Worked example
A biological spore test is positive on Monday morning. What do you do? Reasoning: a positive test means sterilization may have failed. Remove the unit from service, repeat the test with a control, recall all items processed since the last negative test, reprocess or discard them, review loading and packaging, and document the event and corrective action. Do not simply rerun the cycle and use the items.
Traps
Never wash gloved hands; do not rely on alcohol alone for contaminated surfaces; autoclave tape is not proof of sterilization; semicritical items need more than low-level disinfection; and never recap needles with two hands.