The sterilization process in medical and dental practices

Cavitation is the phenomenon behind ultrasonic cleaning: ultrasonic waves generate micro-bubbles inside the liquid in the tank that implode in contact with the instruments. When these implode, they release energy that disintegrates residue, impurities and contaminants, even from the most difficult-to-reach areas, ensuring a powerful yet gentle cleaning action, without damaging the instruments.

No. The ultrasonic tank does not replace sterilization, but is a necessary step before sterilization in an autoclave, since washing ensures the removal of dirt from the instruments. After the cycle in an ultrasonic tank, the disinfection and sterilization process must be completed.

Ultrasonic tanks are ideal for cleaning traditional dental instruments: endodontic files, hand tools, scissors, orthodontic applications, laboratory instruments.

Ultrasonic tanks cannot be used to treat: rotary instruments, untreated or anodised aluminium instruments, hollow instruments, mirrors, diamond burs.

Handpieces must not be treated in ultrasonic tanks, because ultrasonic vibrations can damage the mechanical internal parts and reduce their lifespan. For the safe cleaning of handpieces, we recommend using thermodisinfectors with specific accessories.

Manual washing may be less accurate and more risky for the operator (perforations, cuts, exposure to contaminants). Automatic cleaning, on the other hand, guarantees an even and deep cleaning action without direct contact with the contaminated instrument. In addition, it allows a reduction in the working time of personnel who can dedicate themselves to other activities and a lower consumption of water.

No, the instruments are not dry. They must be dried by hand with paper towels, taking care over sharp and pointed instruments.

 There are two methods of ultrasonic cleaning: 

• Direct: the advantage is that it is simple and enables effective cleaning. The cleaning solution is poured into the tank (only one solution can be used at a time) and the instruments are placed in the perforated basket or suspended. Dirt will settle on the bottom of the tank. 

• Indirect: This method is particularly suitable for washing small instruments such as burs or prostheses. The tank is filled with water and a cleaning solution to improve cavitation. Using the dedicated beaker holder, different cleaning solutions can be introduced into the beakers, so that even instruments of different types can be ultrasonically washed, choosing the solution according to the type of residue to be removed. The dirt will remain in the beaker. 

The temperature varies according to the selected cycle, which differs depending on the type of dirt that must be removed. It is important to use water at the right temperature for two reasons: on the one hand, the use of water above 40°C causes blood to coagulate, making it more difficult to remove; on the other hand, using water that is too hot can cause the denaturation of the enzymatic detergent or an increase in the bacterial load instead of its removal. It is therefore not recommended to place instruments soiled with blood in an ultrasonic tank with a water temperature above 40°C. 

The A₀ is an index of effectiveness of thermal disinfection defined by the EN ISO 15883 standard and can be achieved with different combinations of temperature and time: the higher the temperature, the less time is needed. The standard requires a minimum A0 of 600 for the thermal disinfection of surgical instruments to ensure the elimination of bacteria,

mycobacteria, fungi and viruses. Thermodisinfectors often reach higher temperatures, but allow this parameter to be adapted to meet different needs and local regulations.

Thermal disinfection offers numerous advantages over manual or exclusively chemical methods: 

• Greater safety for the operator: it eliminates direct contact with contaminated instruments, reducing the risk of perforations, cuts and exposure to pathogens. 

• Documented efficacy: thanks to controlled time and temperature parameters, it guarantees constant and measurable levels of disinfection, in compliance with international regulations. 

• Process standardisation: cycles are always the same, repeatable and can be validated, without depending on the skill of the operator. 

• Work optimisation: by automating the process, it frees up time for other tasks in the practice and improves organisational efficiency. 

In addition, unlike ultrasonic tanks and multifunctional tanks, the thermal disinfector also allows you to treat handpieces. 

No, the instruments must be perfectly dry before sealing to avoid condensation that compromises the sterility and seal of the pouch, as well as the corrosion of the instruments themselves.

The pouch must be always larger than the instrument so as to allow proper sealing and the uniform penetration of steam. In general, it is recommended that at least 3 cm remain free between the instrument and the open side of the pouch, and about 1 cm per side. This margin avoids stress on the seal, reduces the risk of tearing and facilitates the sterile extraction of the instrument.

In the Euronda Pro System autoclaves, the pouches should be arranged with the paper side up and the plastic side down, so that the steam can better penetrate inside the pouch. In addition, it is important that the load is evenly distributed on the trays, preventing the bags from overlapping.

Pure water is essential to ensure safe cycles, prevent limescale and extend the lifespan of the devices. The use of unsuitable water can compromise sterilization and damage the autoclave chamber, as well as the instruments themselves.

With water treatment systems, the management and transport of the tanks is avoided, long-term costs are reduced and adequate water is always guaranteed, with less waste and less fatigue for the operator.

Yes, to ensure that sterilization is effective, it is recommended that tests, such as the Vacuum Test, Bowie-Dick test and Helix Test, are carried out regularly through the relevant programs. On the Euronda Pro System autoclaves, you can set a reminder for running test programs at a desired time interval, making it easier to manage the clinic and operate safely at all times.

Traceability makes it possible to record and document all the critical parameters of the washing, disinfection and sterilization cycles (time, temperature, pressure, outcome). This allows you to: 

• Ensure patient safety by guaranteeing that each instrument has been properly treated before use. 

• Demonstrate regulatory compliance, facilitating any checks. 

• Medical and legal protection, providing objective evidence in the event of disputes. 

• Improve the organisation of the practice, with data that is always available and accessible. 

Digital traceability allows cycle data to be automatically stored on a computer or in a network, eliminating errors and the loss of information typical of paper records. The data are immediately accessible, easy to consult and can be integrated with the practice management system, reducing management time for the operator.