Disinfection and Sterilization

Sterilization and disinfection are essential for both personal safety and patient safety. Rather than a cookbook approach, these should be viewed as processes that are utilized based on philosophy. The philosophy of how an item is used, stored, contaminated, reused, or disposed of determines the optimal method of sterilization and disinfection.

Sterilization and disinfection are essential to prevent the chain of infection in the dental office. The chain of infection is:

An entrance through which the pathogen may enter the host.
A susceptible host is not immune or has compromised immunity.
A sufficient number of pathogens or infection-causing organisms must be present to produce infection. This is called the infectious dose. This varies for different infections or diseases. A reservoir or source must allow the infection agent to survive and multiply (e.g., Blood).

When all the events happen together, this is considered as the “Chain of infection”. Effective infection control strategies prevent infection or disease transmission by interrupting one or more links in the chain of infection.

Cleaning is the most crucial step in all decontamination processes. Cleaning involves the physical removal of debris and reduces the number of microorganisms on an instrument or device. If visible debris or organic matter is not removed, it can interfere with the disinfection or sterilization process. Cleaners like Ultrasonic cleaners, Instrument cleaners, and Washer disinfectors work effectively.

There are three categories of patient care items depending on their intended use and the potential risk of disease transmission:

• Critical items: touch sterile areas such as those in an incision or in deep tissues. Dental equipment which touches sterile areas such as bone and blood vessels or penetrates the mucous membrane of the mouth is classified as critical. Examples include Scalpel blades, Perio scalers, and Surgical and dental burs.
• Semi-critical items: contact only mucous membranes and do not penetrate soft tissues. As such, they have a lower risk of transmission. Most of the items like Mouth mirrors, Impression trays, and Amalgam condensers are heat tolerant; they should be heat sterilized between patient uses.
• Non-critical items: contact intact skin. These include Blood pressure cuffs and X-ray heads, among many other things, and pose the least risk of infection transmission.