Validated Ultrasonic Cleaning of Dental Instruments -- MEDICA - World Forum for Medicine


Ultrawave Ltd.

Validated Ultrasonic Cleaning of Dental Instruments

Hygea 1250

The need to clean dental instruments scrupulously prior to sterilization is beyond question. “If it’s not clean, it can’t be sterile”. Equally, the cleaning efficacy of ultrasonic energy has long been appreciated and understood by dentists. The delicate scrubbing action caused by millions of imploding microscopic bubbles is able to penetrate box joints, hinges and threads far more efficiently than any other method, including the latest generation of washer/disinfectors. Most dental practices already use ultrasonic cleaners. Indeed, the Glennie report found that ultrasonic cleaners were present in 92% of surgeries surveyed.

Despite their familiarity with this technology it seems there are several misconceptions prevalent among dentists and dental nurses. Glennie found that 96 % of surgeries never checked either the efficiency of the ultrasonic transducers or the cleaning efficacy of the bath. It is essential that the efficiency should be checked frequently using the aluminium foil ablation test and/or an ultrasonic activity meter. The cleaning performance should be tested by a recognized soil test such as TOSI. It is highly recommended that these tests be incorporated into your weekly maintenance programme. These are fairly simple tests and are relatively inexpensive to conduct.

Dental instruments can often be heavily contaminated, dental cement for example is particularly stubborn and it is important to ensure that your ultrasonic bath is powerful enough to cope. Not all ultrasonic cleaners are equally efficient and do not offer the same levels of power and cleaning ability. Some baths are designed for less arduous applications, such as contact lens cleaning and are powered accordingly.

SHTM 2030 and other guides have acknowledged the merits of ultrasonic cleaning but it is now recognized that standard, general-purpose baths do not fit comfortably within a cleaning protocol based on validation. It is incumbent on all dental practitioners to adopt effective infection control procedures and at the heart of this is the need to provide a fully validated instrument cleaning process. A protocol for each stage needs to be established and the process should be as free as possible from human intervention. Traditional ultrasonic baths have several shortcomings in this respect; it is possible to add or remove items from the bath at any time and thus not complete the full cycle; noise levels can be invasive and there is always the risk of inhalation of contaminated aerosols by the operator if the lid is left off. Today it is no longer enough to clean instruments effectively; it is essential that the process is robust, repeatable and able to be validated.

Recent developments in ultrasonic cleaning baths have gone a long way to overcoming some of these shortcomings. Ultrawave have been manufacturing ultrasonic baths in the UK for more than 15 years and have responded to the changing needs of the industry by developing the innovative hygea - the first Ultrasonic cleaner to incorporate an electromagnetic locking lid mechanism and provide full process validation. Once the cleaning cycle has begun, the integral lid cannot be opened and instruments cannot be removed prematurely. This also eliminates microbial aerosols. The improved insulation of the MDPE lid greatly reduces noise levels.

In the hygea it is possible to pre programme all necessary parameters such as date, location, batch number, operator name, temperature, cycle time. The integral printer provides a print out giving a permanent record for every cleaning cycle.

A number of control devices are incorporated in the design to ensure that the cycle is completed within your chosen parameters. Fluid level sensors monitor the depth of water to make sure that instruments are fully submerged; an activity sensor detects ultrasonic energy; temperature sensors and an integral cooling fan keep the cycle within set parameters (usually between 25 and 35 deg C to prevent coagulation of proteins). If any of these parameters are exceeded, the hygea will abort the cycle and produce a printout detailing the source.

In a busy practice, rapid turnaround of instruments is of paramount importance. Independent testing has shown that even the most heavily soiled instruments can be fully cleaned during a six-minute cycle in the hygea.

As part of the Cleaning protocol, it is important that the bath is dosed with exactly the same concentration of detergent each time. In order to simplify this process, Ultrawave have developed pre-measured soluble sachets- ultracleanSSD - to be used in conjunction with the hygea. This too is designed to save time and ensure the consistency of the process.

There is no doubt that in recent years, awareness of the risks associated with inadequate cleaning has risen dramatically and as a result, standards have also been raised. As these standards continue to rise, the challenge for manufacturers is to design innovative products to make compliance simpler. The hygea ultrasonic cleaner from Ultrawave is a prime example of this, combining proven cleaning technology with new software driven controls to provide powerful ultrasonic cleaning with integral validation.