Sterilization is an essential step in the reprocessing of reusable dental instruments that have become contaminated with saliva, blood or other biological fluids. The aim of sterilization is to break the chain of cross-infection between patients by killing micro-organisms, including spores. The sterilization processes that have traditionally been used include- steam, ethylene oxide (Et), ionizing radiation (gamma or E-beam), low- temperature steam and formaldehyde, and dry heat (hot air). However, keeping up with the trend is equally important. Within the last two to four years, incubation-time for steam and hydrogen peroxide biological indicators are now available in as little as 24 minutes, which can provide a significant improvement in efficiency of the sterilized load release.
Some of the trending techniques in sterilization include –
- Chemical Processes (Gas/Liquid) most of the new methods are oxidative processes based on “peroxy” compounds. These include sterilant based on compounds such as hydrogen peroxide, peracetic acid, peroxyl sulphates, chlorine dioxide, and ozone.
- Low-Temperature Steam and Formaldehyde- It is an example of synergism in that it brings together steam at sub atmospheric pressure and formaldehyde gas—neither of which is markedly sporicidal—to produce a highly efficient sporicidal effect.
- Peracetic Acid- currently used in a number of sterilization processes. Examples include liquid systems such as the Steris machine (Steris Corp., Mentor, OH) for endoscopes, or use as a liquid sterilant in suitable disinfector.
- Hydrogen Peroxide- Hydrogen peroxide as a 3% aqueous solution has long been used as an antiseptic. The use of hydrogen peroxide as a vapor-phase sterilant was developed by Amsco in the United States as the VHP system. This process was originally developed in several formats, including a cassette system for endoscopes, a freestanding system for environmental decontamination, a system for use in sterilizing lyophilizes and isolators, and a general-purpose unit for the sterilization of medical devices.
- Nitrogen dioxide- Nitrogen dioxide is a sterilant gas that is used in the terminal sterilization of medical instruments. The NO2 sterilization process has been validated for the terminal sterilization of medical devices using typical sterilization chamber-based systems. There are unique advantages with the NO2 process that are not available with other sterilant gases. These advantages include operation at room temperature, a relatively low sterilant concentration, rapid microbicidal activity, and minimal sterilant residuals on processed articles. These advantages permit the use of the NO2 process in low-resource environments.
New materials and technologies are continually being introduced into the medical device industry. with increasing regulatory pressures, combined with the need to identify cost-savings, effective sterilization is an area which going to be even more significant in the future.
