Chapter 21: Sterilization

Understanding Disinfection and Sterilization

Pathogens and Spores

  • Importance of killing pathogens and spores in infection control.

  • The need for efficacy based on environmental quality and EPA registration status.

Disinfectant Classification

  • Intermediate Level Disinfectant:

    • Registered by EPA as a hospital-grade disinfectant.

    • Effective against various pathogens but does not kill spores.

Mechanisms to Kill Spores

  • Sterilization: A process designed to kill all microorganisms, including spores.

    • Methods include heat sterilization or using high-level disinfectants.

    • Notably, a higher level of microbial destruction than disinfection.

Responsibilities in Instrument Processing

  • The role of dental assistants includes the preparation of contaminated instruments for reuse.

  • Key steps in the processing chain include:

    • Transporting the instruments.

    • Cleaning to remove debris.

    • Packaging for sterilization.

    • Sterilizing instruments.

    • Storing sterilized instruments.

    • Delivering instruments while ensuring quality assurance throughout.

Disinfection vs. Sterilization

  • Disinfection:

    • Kills transient microorganisms but does not kill all microbial life, specifically spores.

    • May kill certain microorganisms within specific periods as per manufacturer guidelines.

  • Sterilization:

    • The only method that guarantees the destruction of spores.

Safety Measures When Handling Chemicals

  • Personal Protective Equipment (PPE) must be worn when working with toxic chemicals.

    • Utility Gloves: Should be worn to protect against sharps and chemical exposure.

  • Use wipes instead of sprays to minimize aerosol exposure during disinfection.

  • Importance of following safety guides and training protocols when handling disinfectants.

  • Concerns over inhalation of chemicals and long-term health effects discussed:

    • Discussion about unacceptable irritations and individual sensitivities to disinfectants.

Classification of Patient Care Items

  • Items classified based on infection transmission risk to determine treatment methods:

    • Critical Items:

    • Penetrate soft tissue or bone.

    • Must be sterilized by heat.

    • Semi-Critical Items:

    • Touch mucous membranes or non-intact skin.

    • Require heat sterilization or high-level disinfection if not heat-tolerant.

    • Non-Critical Items:

    • Contact with intact skin.

    • Can be cleaned with EPA registered intermediate or low-level disinfectants.

Terms in Instrument Processing

  • Precleaning: Reduces microorganisms by removing debris before sterilization.

  • Disinfection: Kills disease-causing microorganisms but not all microbial life.

  • High-Level Disinfection: Kills most pathogens but not all spores.

  • Intermediate-Level Disinfection: Effective against TB, destroys less resistant organisms.

  • Low-Level Disinfectant: Ineffective against TB; intended for housekeeping.

Workflow Patterns

  • Importance of single-loop processing from dirty to clean to avoid backtracking.

    • Contaminated Side: Responsible for the cleaning process (ultrasonic cleaner, sinks).

    • Clean Side: For packaging, sterilization, and storage; designated to avoid contamination.

  • Recommendations for signage and color coding to reinforce clean vs dirty areas.

Handling and Disposal of Waste

  • Disposal of waste must differentiate between biohazard and regular trash.

  • Saliva-absorbing materials must be placed in biohazard containers.

Cleaning Techniques

  • Recommended methods for cleaning instruments—prefer ultrasonic or automated washing instead of hand scrubbing.

    • Hand Scrubbing: Least preferred due to the risk of injury;

    • Safety measures include goggles, puncture-resistant gloves, and keeping items above waterline to avoid injury.

    • Ultrasonic Cleaning: Uses sound waves to remove debris and is safer than manual scrubbing.

Ultrasonic Cleaners

  • Functionality includes using cavitation bubbles to remove debris.

    • Instruments should be cleaned in the ultrasonic cleaner for 5-15 minutes.

  • Specific solutions should be used formulated for ultrasonic cleaning.

  • Cleaner must be changed regularly (at least daily).

  • Testing for functionality using aluminum foil to ensure cavitation.

Maintenance of Instruments

  • Instruments require thorough drying and lubrication post-cleaning to prevent corrosion.

  • Proper packaging is essential before sterilization to maintain sterility.

  • Types of sterilization packaging must be FDA-approved and clearly labeled to avoid contamination.

  • Special packages include:

    • Sterilization pouches, perforated cassettes, and appropriate nylon tubing.

Sterilization Methods and Precautions

  • Differentiation of sterilization methods:

    • Dry Heat Sterilizers: High temperatures; requires specific packaging to prevent damage.

    • Chemical Vapor Sterilizers: Less corrosive and suitable for hinged instruments.

    • Steam Sterilization: Effective but requires comprehensive wrapping to maintain sterility.

  • Documentation and monitoring recommended during sterilization processes.