Maintenance and cleaning of the autoclave

Tips for maintenance and cleaning of the dental autoclave

Efficiency and longevity of the autoclave

Like any electromechanical device, the autoclave requires a regular technical maintenance programme, which – together with proper management and routine maintenance – is able to guarantee continuous, safe and effective operation, thus avoiding extraordinary expenses, unexpected breakdowns and the consequent slowing down of the practice’s work.

Explained below are a few simple measures, which – together with the technical maintenance plan of the assistance service – will keep your autoclave functioning efficiently for many years.

Some preliminary advice:

  • For proper maintenance of the autoclave, periodically clean all the external parts, using a soft cloth dampened with regular neutral detergents (NB: do not use corrosive or abrasive products).
  • Do not use common abrasive cloths or wire (or other abrasive) brushes to clean the metal parts.
  • Before starting each cycle, thoroughly clean the door seals, using a damp cloth.
  • The formation of white spots at the base of the chamber indicates that poor-quality pure water has been used.

Routine maintenance and cleaning of the autoclave

In addition to the technical maintenance programme, an important role can be played directly by those who use the autoclave every day, by adopting a few simple measures that are very important for the reliability and correct functioning of the autoclave.

N.B.: All operations must be carried out only when the machine is cold and switched off. Disconnect the power supply before carrying out any work.

1. Cleaning the sterilization chamber and the door

Approximately every 100 cycles, the chamber housing the dental instruments must be cleaned. The normal use of the autoclave creates residues and impurities that settle for the most part on the bottom of the chamber, but can be removed using a simple yet important procedure that can be carried out quickly. What to do:

  1. With the machine switched off (and cold), remove all the structures present: basket, trays and tray holders. To disassemble the tray support: remove the support from the chamber (fig. 1) and, once the cleaning is finished, reassemble it, following the same procedure in reverse.
  2. Use a cloth, or the sponge provided, wet only with distilled or pure water (with no detergent) (fig. 2). NEVER use disinfectants to clean the chamber.
  3. Clean all the surfaces of the chamber with the sponge, in particular the bottom and the door, also paying attention to the folds of the seal at the mouth of the chamber, as this is where residues and impurities tend to accumulate most.
    CAUTION: Take care not to damage the probe at the bottom of the chamber.
    Clean the seal and the door with a soft cloth, dampened with water or vinegar to remove limescale. This cleaning operation must be carried out to remove any impurities that may cause the sterilization chamber to lose pressure and the seal to be cut.

Fig. 1

Fig. 2

2. Cleaning the water tanks

Periodic cleaning of the tanks is also recommended to keep the autoclave functioning better and longer. How to do it correctly:

  1. Empty the fresh water tank: insert the connected end of the hose supplied into the connection at the bottom of the front panel (Position 1 of fig. 3) and the other end into an empty container.
  2. Empty the internal waste water tank: insert the transparent hose supplied with the appliance into the connection at the bottom of the front panel (Position 2 of fig. 3) and the other end into an empty container.
  3. When drainage is complete, remove the tube from the coupling by pressing the button on the coupling.
  4. Remove the cover to gain access to the tanks: lift the cover at a 45° angle (Position 1 of fig. 4) and pull it towards you (Position 2 of fig. 4).
  5. Using the sponge provided, clean off any deposits and impurities that normally settle on the walls and bottom. It is important to remove the material in order to protect the filters, which could otherwise become clogged. CAUTION: During these cleaning operations, take care not to damage the floating level sensors in the tanks.
  6. Remove the filters and clean them under a jet of water (fig. 5). After this last operation, re-insert the filters and refill the tank.
  7. Rinse carefully and empty the water used for this operation.
  8. Run a sterilization cycle without loading.

Fig. 3

Fig. 4

Fig. 5

3. Safety valve maintenance

  1. Access the safety valve assembled on the rear of the appliance.
  2. Loosen the cap on the top of the valve in an anti-clockwise direction (fig. 6), until the end of the stroke is reached and the valve runs freely.
  3. Return the cap to its original position, screw it back on, and repeat the operation at least a couple of times.
    N.B.: This operation is necessary in order to ensure the safety valve continues to function correctly. Make sure that the cap is tightly closed at the end of the operation!
Consigli sulla manutenzione dell'autoclave_illustrazioni divise-06

Fig. 6

4. Adjustment of the closure system

The appliance closure system requires an occasional adjustment, due to normal settling of the mechanical parts and wear of the seal. This is particularly important, because an inadequate seal may prevent the pressure rising correctly to the value set by the selected program, and thus compromise the outcome of the cycle.

  1. Open the door. Always ensure the machine is switched off and cold.
  2. Insert the adjustment lever (supplied) into the slot under the door (fig. 7).
  3. Check whether the lever has engaged the adjustment pin, looking from the slot of the door hook (fig. 7).
  4. Rotate the adjustment pin anti-clockwise by 1/4 of a turn, looking at the door (to close) (fig. 8).
  5. Check that the door closes normally. If the handle is too hard to close, rotate slightly from the opposite direction from before (clockwise).
  6. Perform a test run to check that the adjustment has been effective.

Fig. 7

Fig. 8

5. Problem: rust formation

The formation of rust on the surfaces of the autoclave or instruments is caused by the introduction of already rusty instruments, even if made of stainless steel, or by instruments made of normal steel, which cause galvanisation phenomena.

Often even a single instrument with a rust stain is enough for rust to form and develop on the instruments and in the autoclave.

Another factor that causes rust in the sterilizer is the use of water containing chlorine, such as drinking water, sea water or water with disinfectants or detergents. Use only good-quality distilled water.

If rust forms in the appliance, clean the walls of the sterilization chamber and the tray holder using special products for stainless steel, as described in sections 1 and 2 above.

6. Problem: dark rings in the chamber

The dark rings that can be seen inside the chamber are usually due to the deposit of residues of oil and/or dirt from the instruments, which during the sterilization process inevitably release substances into the hydraulic circuit of the autoclave. During normal cycle processes, the autoclave can bring these residues back into the boiler.

  1. If this occurs, we suggest that you first ensure the instruments have been sufficiently cleaned and not over-lubricated before they undergo the autoclave cycle.
  1. Secondly, we suggest regular cleaning of the chamber surface as indicated.

7. Technical assistance request messages

In many cases, the autoclave itself signals a problem or malfunction on the display. Should this occur, do not delay: contact the authorised technical assistance immediately. Even a small malfunction, if ignored, can lead to further problems and complications, further compromising the autoclave. Any worn or damaged parts must be replaced promptly by the technician, to ensure the autoclave functions perfectly by preserving the other components.