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Dental Autoclve

How to Do the Sterilization

Steam dental autoclaves are the most commonly used type of heat sterilizer in dental practices. Two types of processes employ steam under pressure. The difference between the two is the manner in which the machine evacuates the air from the sterilization chamber and then introduces the steam.

Gravity displacement sterilizers rely on the forces of gravity to force air out of the chamber through air escape vents. The steam entering the chamber from the water reservoir displaces the air as it leaves the chamber. The combination of pressurization of the chamber, steam and a high temperature for a prolonged period has the ability to kill virtually all microorganisms. This is the most common type of autoclave found in dental offices in the United States. A typical cycle for wrapped instruments includes heat-up and pressurization time, followed by a 15-to-30-minute cycle during which sterilization is taking place (121°C at 15 psi). The sterilization cycle time decreases as the temperature is increased.

It is important to use cycle times and temperatures described in the owner’s manual, and never to interrupt the sterilization cycle to remove or add items, or for any other reason. Interruption of the cycle will result in instruments that are not sterile and therefore not safe for use on patients. After the sterilization cycle, the sterilizer must depressurize and the packs remain in the sterilizer for drying. The drying phase may take anywhere from 20-45 minutes. The unit must only be opened after completion of the drying cycle. Upon removal from the sterilizer, sterile packs must be stored in a clean, dry area. Packs that become wet, torn, contaminated, or otherwise compromised require resterilization.

Dry-heat sterilization employs high temperatures for extended periods to achieve sterilization of dental equipment. The method of heat circulation in dry-heat sterilizers is usually convection, which helps to ensure that the heat circulates throughout the sterilization chamber during the process. Mechanical convection is more effective; the sterilizer contains a fan or blower that continually circulates the heated air to maintain a uniform temperature throughout the chamber. Most commercially available dry-heat sterilizers on the market today are of this type.

The higher temperature of a dry-heat sterilizer means that paper will scorch and plastic will melt. Specialized packaging material is available for dry-heat sterilizers. Most handpieces will not tolerate the higher temperatures of a dry-heat sterilizer. Mechanically driven handpieces that contain turbines and bearings are susceptible to damage at higher temperatures. The manufacturer’s instructions should be checked for compatibility of instruments, devices, and materials with the unit and the handpiece manufacturer’s instructions should be followed for preparation of the handpiece prior to sterilization and for sterilization itself.

dental equipment

The Way to Replace Parts of Dental Sterilizer

Autoclave sterilizers have been known to play a significant role in the daily functioning of dental operatories and are recently becoming even more advanced and efficient due to advances in technology. Development of a new generation of autoclaves within the last two decades has added a new dimension to this heat sterilization modality. These autoclaves are classified as “Class B” sterilizers or “pre- and post-vacuum” steam sterilizers. The equipment is fitted with a pump that creates an initial vacuum in the chamber to ensure air is removed from the sterilizing chamber before steam enters.

The latest innovations allow for fast and easy use for efficient instrument processing, reliability and effectiveness for infection control assurance, automatic opening door for efficient instrument drying, and maximum space utilization and a complimentary design for your sterilization area. Although these sterilizers can be a somewhat costly addition to a dental operatory, the time and money that they save dentists down the road is substantial. Taking a few pointers into consideration and performing routine checks and replacing old parts on your unit can help maximize the life and functioning of your model.

Door Gasket: To replace the door gasket, begin by simply removing the old door gasket. Clean the gasket groove in the door, and chamber face. For easy installation of the new gasket, use the “South-East-West-North” method (i.e. begin installing the gasket at the bottom of the door, then install the left and right sides and finishing at the top by squeezing in any of the excess making sure that the gasket fits flush).

Dam Gasket: Use CAUTION when removing or installing the dam gasket –the door studs can be sharp. To install the door dam, align and place the dam gasket on and over the door studs. The dam must lie flat against the door (refer to the Installation Instructions included with the MIG035 dam gasket).

Chamber & Vent Filters (mesh style filter): If the machine has both a Chamber and a Vent Filter – Remove all trays and the rack from the chamber. Clean the chamber, then remove the chamber filter. Install the new filter. You must also replace the Vent Filter that serves as a filter for the steam trap/bellows and is located in the vent line to the tee fitting. Reinstall rack and trays.

Sterilizer: After replacing the PM parts, check the reservoir and clean if dirt or debris are present (Note: Debris is the number one reason for Steam Trap/Bellows failure). Refill reservoir with distilled water only. Conduct a temperature check using a Max Register Thermometer. Conduct a pressure check to identify any leaks that may need to be addressed. If calibration is necessary, use the RPI Pressure Gauge and the RPI Trim Pot Tool.