Sterilization and Disinfection

https://www.cdc.gov/dental-infection-control/hcp/summary/sterilization-disinfection.html

Reprocessing

Dental practice should have policies for

• Containing, transporting, and handling contaminated instruments

• Each instrument has its own reprocessing instructions

• Single use devices = no reprocessing instructions and dispose of

Classification of Patient-Care Items

Patient-care items are classified based on risk of infection transmission:

1. Critical items

2. Semicritical items

3. Noncritical items

Critical patient care items

Items that penetrate soft tissue or bone.

Examples

• Surgical instruments

• Periodontal scalers

Infection Risk

• Highest risk

Processing

• Must always be heat sterilized

Semicritical Items

Items that contact

• Mucous membranes

• Non-intact skin (exposed skin, chappeed, dermatitis)

Examples

• Mouth mirrors

• Amalgam condensers

• Reusable impression trays

Infection Risk

• Lower than critical items

Processing

• Heat sterilization is preferred (most are heat tolerant)

• If not heat tolerant — replace w/ heat tolerant alternative or disposable

• If neither is available → High-level disinfection (minimum).

Noncritical Items

Items that contact intact skin only.

Examples

• Radiograph cone/head

• Blood pressure cuff

• Facebow

Infection Risk

• Lowest risk

Processing

• Cleaning only

If visibly soiled:

• Clean

• Then disinfect using an EPA-registered hospital disinfectant

Disposable barriers may also be used.

Important exception: Dental handpieces

• Low speed motors

• Reusable prophylaxis angles

Although classified as semicritical, they:

• Become contaminated during use.

• Must always be heat sterilized between patients.

• Do NOT use high-level disinfection or surface disinfection alone.

Digital Radiography Sensors

Classified as semicritical.

During use

• Protect with an FDA cleared barrier

Between patients

• Clean

• Heat sterilize or

• High-level disinfect (if manufacturer allows)

If sterilization/high-level disinfection is not possible:

• Keep barrier protection

• Clean and disinfect using an EPA-registered hospital disinfectant with intermediate-level (tuberculocidal) activity

Always follow the manufacturer's reprocessing instructions

Instrument Processing

Cleaning

• Clean before sterilization or disinfection

Why?

Blood, saliva, and debris can hinder effectiveness of sterilization or disinfection

Automatic cleaning equipment

• Ultrasonic cleaner or washer disinfector — used to remove debris or improve cleaning

After cleaning

• Inspect instrument, wrap into packages, heat sterilized

• Label each package (sterilizer used, cycle, date, expiration)

Sterilization monitoring

1. Biological monitoring

2. Mechanical monitoring

3. Chemical monitoring

Biological monitoring

Most reliable method — kills high resistant bacterial spores (bacillus species)

• Must be done at least 1x a week

• Results are not immediate

Mechanical monitoring

• Monitors procedural errors and equipment malfunctions

• Monitors pressure, temperature, exposure time (gauges, computer displays, prints)

They help record during sterilization records

• usually the first sign of equipment malfunction

Chemical monitoring

Uses chemicals that change color when exposed to high temperatures (sterilized conditions)

• Indicator tape, stripes, package markings

• Provides immediate result after cycle

• Must be used inside every package to very sterilizing agent has penetrated package (internal chemical indicator)

• If cant use then must use external indicator

• No color change = don’t use instruments

• Distinguishes processed from unprocessed packages.

Internal chemical indicators

Single parameter

• Measures 1 sterilization parameter through time or temperature

Multiparameter

• Measures 2+ parameters through time+ temp or time + temp + steam

• More reliable

Sterilization monitoring

Sterilization must be monitored

• If problem (uncahnged chemical indicator or positive spore test) — document

• Sterile supplies must be stored in closed cabinets or wrapped

• Pacakaging can’t be torn— compromised packages needs to be reprocessed

Recommendations for sterilization of care devices for dental

• clean and reprocess equipment before and after use according to instructions

  • If no instructions = might not be multiuse

• Assign reprocessing responsibilities to DHCP

• Wear PPE during reprocessing

• Use mechanical, chemical, and biological monitors

Environmental infection prevention and control

Important policies

• Clean before disinfect or sterilization

  • Cleaning: Removes dirt, debris, microorganisms

  • Disinfection: Kills most disease-causing microorganisms but does not necessarily destroy bacterial spores (unlike sterilization).

Clinical contact surfaces

Frequently touched urface — can be contaminated during treatment

• Light handles, bracket trays, unit switches, computer keyboards/ equipment, dental chair controls

• Can transfer to DHCP, patients, hands etc

Prevention

• Disposable surface barriers between patients

• No barriers? —> clean surface + disinfect w/ EPA registered hospital disinfectant

• Has blood? —> Use intermediate level disinfectant (tuberculocidal claim)

Floors, walls, sinks = low infection risk

• Use soap and water + disinfect if blood stain