Sterilization is routinely done in dental setups but not up to the INTERNATIONAL STANDARDS. We as a dental community have a responsibility in our society of stopping the spread of infection by improving sterilization protocols up to the required standards.
Main elements are required to spread infection.
1. Susceptible host
- Causative agents
- Modes of transmission
- Direct contact with body fluids
- Indirect contact with contaminated objects
- Droplet (contact of mucosa with splatter)
Every practice should treat all patients as if they are potentially infective and same safe standards should be routinely applied. There are a few principles that should be applied necessarily in all the dental practices:-
- PROTECTIVE MEASURES
- HEALTH STATUS OF THE PATIENT BY TAKING DETAILED MEDICAL HISTORY
- IMMUNE STATUS OF THE DENTISTS, DENTAL ASSISTANTS, DENTAL NURSES
- ALL INSTRUMENTS SHOULD BE STERILIZED PRIOR TO THE SURGERY
- SURGERIES SHOULD BE DISINFECTED THOROUGHLY AFTER EVERY PATIENT
- BARRIERS SHOULD BE APPLIED ON ALL WORKING SURFACES TO AVOID CROSS CONTAMINATION
- HAND HYGIENE
Single most important measure for preventing transmission.70-90% alcohol based hand rub should be used before and after direct contact with patient; and also after contact with SURFACES, INSTRUMENTS, LAB EQUIPMENTS AND MATERIALS.
- PERSONAL PROTECTIVE EQUIPMENT
It protects the patient and the dentist from becoming the vector for transmission of microorganisms. It includes:-
- GLOVES: use of gloves doesn’t replace the need for hand hygiene. Effective hygiene protocols should be followed before and after using gloves. Any surface which is not covered with barriers should not be touched with gloves e.g. drawers, cellphones, doors etc.
- PROTECTIVE EYEWEAR
- DENTAL CLOTHING
- SURFACE COVERINGS any surface that is to be touched with gloves during patient care should be covered with barriers.
- HIGH VOLUME SUCTION should be used whenever creation of droplets, splatter and spray is suspected.
- CLEANING, DISINFECTION AND STERILIZATION OF PATIENT CARE ITEMS
- CLASSIFICATION OF DENTAL INSTRUMENTS
Dental instruments are classified into 3 categories depending on the risk of transmitting infection
- Critical instruments
- Semi-critical instruments
- Non-critical instruments
CRITICAL INSTRUMENTS: They penetrate the soft tissues or bone, and enter into direct contact with blood stream. They should be sterilized before use e.g. forceps, scalpel, scalers and burs.
SEMI-CRITICAL INSTRUMENTS: Come into contact with mucous membranes or non-intact skin. They should be sterilized or high level disinfected. They include RESTORATIVE INSTRUMENTS, MIRRORS AND HANDPIECES.
NON-CRITICAL INSTRUMENTS: They come in contact only with intact skin. Intermediate level disinfection is required. These include X RAY HEAD, B.P CUFFS AND PULSE OXIMETERS.
After use the contaminated instruments should be placed in a puncture resistant container, and then transported to the processing area, soaked in water to prevent drying of debris. Here they are cleaned by scrubbing with a surfactant (enzymatic or non-enzymatic), and later rinsed with water. After proper inspection of cleaning, instruments are packed in suitable materials which are:-
WRAPPED PERFORATED INSTRUMENTS CASSETTE
PEEL POUCHES OF PLASTIC OR PAPER
WOVEN OR NON WOVEN STERILIZATION WRAPS
Once properly packaged, instruments are sent to the sterilization sections which should include THE STERILIZER AND PROPER SPACE for loading and unloading.
Sterilization measures are:-
- Steam under pressure for heat tolerant instruments
Steam autoclave 121 C (250 F) 15min
Unwrapped items 132 C (270 F) 3min
- Dry heat
- Unsaturated chemical vapors
Operating parameters and instructions recommended by manufacturer as well as chemical and biological indicators should always be followed. Frequently used sterilization system is a type B autoclave, which uses vacuum assisted sterilization.
AFTER STERILIZATION IS DONE, BIOCHEMICAL AND MECHANICAL MARKERS should be checked to ensure that proper sterilization is done. Sterile or single use items should be properly enclosed for storage and later use.
NON CRITICAL and HEAT SENSITIVE items should be cleaned with high level disinfectant (2% glutaraldehyde, 7% accelerated hydrogen peroxide, 0.2% para acetic acid) followed by thorough rinsing with water.
DENTAL OFFICE MAINTENANCE
Surfaces such as light handle and door knobs can become contaminated during patient care, acting as vector for microorganism transmission. They should be thoroughly cleaned.
Any surface that comes in direct or indirect contact with blood or saliva should be cleaned with a disinfectant after every procedure. Housekeeping surfaces which have a limited risk of disease transmission can be periodically cleaned with dilute detergents. Disinfection by household bleach should be done if suspected of blood or saliva contact. Suction lines should be purged with water or cleaning solutions between patients.
One area where dentists fail to apply proper sterilization protocols is when handling LAB materials. Impression and prosthesis should be disinfected and placed in an impervious bag before sending it to the lab. Finished prosthesis and appliance delivered to patient should be free of contamination, accomplished with a low level disinfectant.