Infection Control in the Dental Office – Exam Review

Unit 1. Principles and Fundamentals of Infection Control

Unit 2. Sterilization and Disinfection

Chain of Infection

• Transmission always requires all three links:

  • Causative agent (pathogen)

  • Susceptible host

  • Mode of transmission

• If any one link is broken, the disease cannot spread.

• PPE can eliminate (or greatly reduce) the mode of transmission.

Key Terms

• Causative agent = micro-organism/pathogen that can cause disease.

• Susceptible host = person whose immune system cannot resist the pathogen.

• Mode of transmission = pathway by which the infectious agent spreads.

Immunization & Post-Exposure Management

• CDC strongly recommends vaccination for: influenza, measles, mumps, rubella, chickenpox (varicella).

• Every dental office should maintain written policies indicating which immunizations are required/recommended for team members.

Post-Exposure Protocol

• Exposure routes: skin, eyes, mucous membranes, parenteral contact with blood/OPIM (other potentially infectious materials).

• Essential steps:

  • Immediate post-exposure evaluation & follow-up.

  • Confidential written exposure report.

  • Report handled by a designated infection-control coordinator.

Standard Precautions (Universal Precautions)

• Treat all blood & body fluids as if they are infectious.

• Core element: proper use of Personal Protective Equipment (PPE).

Personal Protective Equipment (PPE)

Overview

• Categories: protective eyewear/face shields, protective clothing, masks, gloves.

• Purpose: shield skin & mucous membranes from blood/OPIM.

Protective Eyewear

• Protects eyes & ocular mucosa from spatter.

• Types: safety glasses, goggles, full face shield.

• Cleaning: wash with soap & water when soiled.

Protective Clothing

• Lab coats, jackets, gowns, aprons.

• OSHA: long-sleeved gown required for procedures with potential spatter.

• Scrubs/street clothes ≠ PPE.

Masks

• Protect both wearer & patient.

• Requirements:

  • Snug facial seal.

  • Change between patients.

  • Remove by strings; contaminated gloves must never touch face/hair.

  • Never hang a used mask around the neck.

Gloves

• Worn for exams, treatment, clean-up, or touching contaminated surfaces.

• Change & discard between patients.

• Hand hygiene before donning & after removing.

• If torn/punctured: remove, wash with antimicrobial soap, don new pair.

• Utility gloves (puncture-resistant, reusable) for disinfection/clean-up only.

• Latex allergy/contact dermatitis: supply non-latex alternatives.

Oral Surgery–Specific Measures

• Pre-op antimicrobial handwash.

• If glove tear occurs: remove → hand hygiene → reglove.

• Use sterile surgical gloves; option to double-glove or add glove liners.

• Water supply: employ sterile water delivery systems (single-use, disposable or autoclavable tubing) rather than standard dental unit water.

Cleaning, Disinfection & Sterilization – Core Definitions

• Cleaning: physical removal of debris; lowers microbial load.

• Disinfection: kills most micro-organisms but may not destroy bacterial endospores.

• Sterilization: destroys all micro-organisms including bacterial endospores.

Instrument Classification

Sterilization Methods

1. Steam (Autoclave)

• High-temperature steam under pressure.

• Pros: economical, reliable, rapid, can sterilize bagged/wrapped instruments.

• Cons: potential rust/corrosion, may dull sharps & damage plastics.

2. Dry Heat

• For moisture-sensitive instruments (e.g., orthodontic pliers, burs).

• Pros: inexpensive, no rust/corrosion.

• Cons: long cycles, very high temperatures may damage items; loading time longer.

3. Unsaturated Chemical Vapor

• Uses heated chemical solution (formaldehyde, alcohols) under pressure.

• Pros: fast, reliable, non-corrosive, compatible with paper packaging.

• Cons: can damage plastics, higher operating cost, poor penetration of heavy packages, requires ventilation, chemical waste disposal.

Instrument Processing Area (Four Zones)

1. Receiving/Cleaning/Decontamination
2. Preparation & Packaging
3. Sterilization
4. Storage

Zone Details

• Cleaning (Zone 1)

  • Remove blood/saliva/tissue via hand scrubbing (with puncture-resistant gloves) or ultrasonic cleaner.

• Preparation & Packaging (Zone 2)

  • Arrange instruments on preset trays or in pouches/wraps to keep items sterile after processing.

• Sterilization (Zone 3)

  • Monitoring:

  • Mechanical (time-temperature gauges).

  • Chemical indicators (internal & external) each load.

  • Biological indicators (spore tests) per schedule/state law to verify microbial kill.

  • Failure in any monitor → re-sterilize before use.

• Storage (Zone 4)

  • Store sterile items in clean, enclosed area.

  • Packages must remain dry & intact; if compromised → re-process.

Levels of Disinfection

• Effectiveness depends on concentration & contact time → always follow manufacturer’s IFU.

Environmental Surfaces

Clinical Contact Surfaces

• Frequently touched during care or splattered (countertops, light handles, X-ray controls).

• Prefer barriers; if none used:

  • Intermediate-level disinfectant if visibly soiled or blood-contaminated.

  • Low-level disinfectant if no visible contamination.

Housekeeping Surfaces

• Walls, floors, sinks, etc. — low infection risk.

• Clean on regular schedule with detergent + water or low-level disinfectant.

• Always wear appropriate PPE; mix fresh solutions daily.

Blood Spills

• Decontaminate immediately with intermediate-level disinfectant; wear utility gloves & full PPE.

Waste Management

• Non-regulated waste (majority): used gowns/masks, lightly soiled gauze, barriers → discard with regular office trash.

• Regulated waste: items soaked/dripping with blood/OPIM, sharps, syringes, scalpel blades.

  • Follow OSHA & state rules for packaging, labeling, disposal.

• Sharps: puncture-proof, leak-proof, biohazard-labeled containers.

• Biopsy specimens: sealed, leak-proof, rigid container with secure lid; exterior disinfected if contaminated; biohazard label.

• Disposal of liquid blood/OPIM into sanitary sewer → comply with local regulations.

Dental Unit Water Quality

• Maintain ≤ 500 CFU/ml (colony-forming units per milliliter) as per CDC.

• Strategies: independent water reservoirs, chemical treatments, in-line filters.

• Flush waterlines 20–30 seconds after each patient.

Prostheses & Impressions

• Rinse under running water → spray/immerse with intermediate-level disinfectant → record agent & exposure time on lab slip.

Chairside & Pretreatment Protocols

Before Patient Arrives

• Remove unnecessary items from operatory.

• Set up three-tray system (instruments, supplies, disposables) to avoid opening cabinets mid-procedure.

• Decide barrier vs chemical disinfection plan for surfaces.

• Prepare waterlines per manufacturer maintenance schedule.

• Perform hand hygiene; don PPE.

During Patient Care

• Follow neutral-zone or cassette system for passing sharps; avoid hand-to-hand transfer.

• Keep sharp tips oriented away from clinicians.

• Never recap needles with two hands (use one-hand scoop or engineered device).

Radiographic Infection Control

• Barrier covers on tube head, exposure switch, sensor/film holders.

• After exposure: wipe saliva/blood; place films in cup; in darkroom peel outer wrap, drop film onto clean surface.

• Digital sensors: FDA-cleared barriers + intermediate-level disinfection between patients.

Summary – Key Takeaways

• Break the chain of infection by controlling at least one link: agent, host, or transmission.

• Adhere to CDC vaccination recommendations & maintain written office protocols.

• Implement Standard Precautions at all times; PPE is mandatory.

• Understand instrument categories (critical/semi-critical/non-critical) & process accordingly (clean → disinfect → sterilize).

• Choose the appropriate sterilization method (steam, dry heat, chemical vapor) & verify with mechanical, chemical, and biological monitoring.

• Use the four-zone processing area to prevent cross-contamination.

• Match disinfectant level (high/intermediate/low) to the clinical scenario.

• Manage environmental surfaces, water quality, and waste per CDC/OSHA/state regulations.

• Maintain rigorous sharps safety and radiographic infection-control measures to protect both patients and the dental team.