• Understanding water quality - water quality in dental practice

    Various forms of water are used in the dental practice. The previous article, ‘Dental unit waterlines’, focussed on waterline biofilm issues. In this second article, Professor Laurence Walsh summarises key aspects of water quality that impact on instrument reprocessing and sterilisation.


    Tap water has dissolved oxygen and other atmospheric gases. Aerators on taps slow the flow to reduce splash, but they increase the dissolved gases. Degassing of water is essential to remove dissolved gases before undertaking ultrasonic cleaning of items.


    Water used in instrument cleaning should have low levels of viable bacteria and bacterial products such as endotoxin, and be free of heavy metals and other contaminants. A key property of water that is used with detergents is its hardness. In hard water, there are high levels of calcium and magnesium salts, particularly carbonates, bicarbonates, sulphates and chlorides. This causes faster build-up of limescale, which can foul plumbing in the water distribution system, as well as major problems with detergents, such as low foam height and reduced surfactancy. The reason for this is that calcium or magnesium ions form insoluble salts with detergents, reducing their surfactant effects. Instead, they create a coating of insoluble stearates on the surface of instruments. This is equivalent to ‘soap scum’ seen in a shower recess.

    Water softening creates soft water by replacing the calcium and magnesium ions in the water with sodium or potassium ions, so that no insoluble products are created by the reactions with detergents. Typically, water softening uses an ion-exchange resin. When all the available sodium or potassium ions in the resin have been replaced with calcium or magnesium ions, the resin must be re-charged by eluting the bound calcium and magnesium ions off the resin using a very strong solution of domestic salt (sodium chloride).

    The hardness of ground water varies considerably around Australia, and water hardness problems are often encountered. This is why some detergents used for instrument cleaning include chelating agents such as citric acid or EDTA, which act as softening agents.


    In short, the answer is no. Normally, rainwater collected into polyethylene tanks is soft as it has low levels of calcium and magnesium ions and so forms a strong lather with detergents. Rainwater stored in concrete-lined tanks becomes hard due to dissolved calcium hydroxide that has been released from Portland cement into the water. Overall, rainwater is not well suited for use in a sterilising room. It is neither sterile nor is it free of anions and cations. Rainwater picks up multiple contaminants from the atmosphere (dust, pollutant gases) and from where it has been collected (off a roof). Normally, rainwater is acidic due to the presence of dissolved carbon dioxide (carbonic acid) as well as containing traces of sulphuric acid and nitric acid, both of which are derived from natural atmospheric sources and from industrial activity


    Demineralised water is used for steam generation in steam sterilisers. Tap water is not suitable because this contains many cations (calcium, magnesium, aluminium, sodium, potassium, iron, and copper ions) and anions (phosphates, carbonates, sulphates, silicates, chlorides, fluorides). Precipitation reactions will cause scale build-up on water heating elements in steam sterilisers, in the same manner as occurs in water distillers, kettles, clothes irons and steam cleaners. In water distillers, regular removal of this white or yellowish mineral scale left on the heating elements of the distiller must be undertaken with an appropriate agent such as citric acid or dilute sulphuric acid.

    Water may be demineralised, i.e. rendered free of cations and anions, by one of three different processes – distillation, ion exchange in a deioniser resin, and reverse osmosis (RO). While these processes remove ions, they do not remove uncharged materials including organic compounds and microorganisms. Deionised, distilled and RO water are not sterile.

    When water is boiled the condensate is collected, resulting in distilled water free of inorganic minerals, and so is suitable for use in a steam steriliser. Distilled water does not have a neutral pH (7.0), but rather tends to have a low pH, caused by carbon dioxide from the atmosphere dissolving back into the water, forming a dilute solution of carbonic acid. When distilled water is made, the collection container is normally not sterile and so distilled water almost always contains some viable bacteria. To avoid this, additional treatment (such as ozonation or short wavelength ultraviolet light treatment) would be needed. The same holds true for deionised and reverse osmosis water; as with distilled water these are not sterile.

    Many dental practices use water deioniser cartridges to generate water for use in a steam steriliser, as the process is easier, less expensive and more energy efficient than distillation or reverse osmosis. In a water deioniser unit, an ion-exchange resin exchanges dissolved cations and anions for hydrogen ions and hydroxide ions. A water deioniser does not remove uncharged organic molecules or bacteria, except by incidental trapping in the resin. As mentioned above for water softening resins, the ion exchange resin beds in a water deioniser unit have a limited capacity and need to be regenerated or replaced periodically. In many cases, this is on a regular schedule (e.g. three monthly) based on the water flow through the cartridge. Often deioniser cartridges are fed by sediment and carbon filters, and will have their own replacement sequence. It is essential to follow the supplier’s advice on when the different cartridges in a multi-cartridge system should be changed. Commercial test strips and meters to check water quality are readily available for monitoring ion content.

    The process of RO uses high pressure to force water through a semipermeable membrane to remove ions, molecules, and larger particles including some bacteria. Tap water pressures of around 40 psi can drive a small RO unit. An RO system must have pre-treatment filters to stop membranes clogging. As with water deionisers, RO filter cartridges need to be changed on a regular basis as per the supplier’s instructions. RO water tends to have a neutral pH, but can be too soft and thus corrosive to pipes and control blocks which is why RO water is not approved for use in many types of dental chairs. Similar issues can occur when using distilled or deionised water, since these are mineral-free and can be very aggressive in reacting with some types of dental unit control blocks.

    An additional issue with an RO system fed from mains pressure water is that they tend to have low recovery (5-15%) and so will use a lot of water that will be discharged as waste water into the drains. Surprisingly, this can lead to high water usage bills.

    To achieve sterility, the steam in a steriliser must condense to transfer the latent heat of condensation onto the instruments or items. This raises an important problem when the water for steam generation is condensed and then re-used in later cycles, rather than being dumped. In re-used water, contaminants (such as handpiece lubricants) build up progressively over time, leading to problems with superheated steam that is too dry and will not condense. For steam sterilisers that condense and re-use water in multiple cycles, demineralised water must be completely replaced every week, and not just topped up.



    Insurance issued by Guild Insurance Limited ABN 55 004 538 863, AFS License No. 233791 and subject to terms, conditions and exclusions. This article contains information of a general nature only, and is not intended to constitute the provision of legal advice.  Republished from the ADA News Bulletin, December 2017 No 471 and February 2018 No 472 with the kind permission of the Australian Dental Association. Guild Insurance supports ADA through the payment of referral fees. Please refer to the policy wording and policy schedule for details. For more information call 1800 810 213.

  • Business cyber security obligations

    Did you know that approximately 4,000 reports of cybercrime are reported to the Australian Cybercrime Online Reporting Network every month? That’s a lot of cyber-attacks to arm yourself against.

    While you might do your best to protect your business, do you know what to do if your business is under attack? And do you know what your obligations are when dealing with an attack?

    Download your copy of Business Cyber Security Obligations and learn the essential strategies to preparing for a cyber-attack and the legal obligations you have to your clients and staff.



  • If you fail to plan, plan to fail.

    In business, continuity is the key baseline for success.  It might seem obvious, but it’s surprising how many people rely on your business opening its doors everyday.

    Too often businesses are caught off guard and aren’t prepared when the unexpected happens. While it’s often impossible to reduce the likelihood of many of these events from occurring, business owners can reduce the impact they have by having a plan for what they’ll do if one of these events were to occur.

    Examples of this include:

    • Storm/cyclone
    • Fire
    • Flood
    • Loss of power

    Business continuity plans (BCP) help businesses stay operational during natural disasters, economic downturns, bad publicity and internal conflict or change. Ensuring a business has the correct insurance to continue functioning regardless of internal or external factors, is absolutely key to that business’s success, regardless of size. A BCP is essentially preparing your business for the worst. It is a formal response to a disaster that can help mitigate the impact of continued business interruption. Any business can face an unexpected event that will lead to the business being unable to operate for a period of time. Without a business continuity plan, you may have to figure out solutions in times of stress, and are reactive rather than proactive, which may result in you missing important steps, overlooking risks, and aggravating the impact of the loss. Imagine yourself in an emergency: would you rather have a plan or figure it out as and when the event occurs? It’s about implementing a step-by-step plan for the future should an emergency occur.

    Many business owners feel that they can come up with an “Emergency Plan B” at very short notice to work through a crisis. The reality is that in order for you to be successful with the least amount of downtime, the planning needs to done well in advance. The most effective plans are tailored to your business which requires time to fully imagine various scenarios to come up with solutions to allow your business to move forward even in times of uncertainty. A good BCP will help alleviate weaknesses that are emerging from within the business.

    All BCPs ideally should be unique as they need to be created for the individual needs and operations of the business.

    When businesses create their BCP, they need to consider the following:

    • How vulnerable are you to a major disruption? (for example, are you in a high bushfire area or a cyclone area)
    • How will a major disruption affect the business and the clients of the business? Will clients go elsewhere for the service they require?
    • How long will the business not be able to operate? And how long can the business survive if not operating?

    Some matters to consider including in a BCP are:

    • Possible temporary sites the business can operate from if the usual place of business can’t be accessed
    • Evacuation plan
    • A list of critical tasks needed to keep the organisation operating, such as how to access data and systems as well divert phones for communication
    • Emergency contact numbers (such as for utility providers, insurers, clients, suppliers)
    • Who is responsible for key actions
    • List of current assets

    Be sure all staff are educated on the plan and have rehearsed elements of the plan, such as an evacuation and accessing data off site.

    Plans should be continually reviewed and updated over time to be sure they match the business’ current needs.  For example, if the business changes locations or adds to the services provided, this will require a review of the BCP.

    A BCP gives guidance and takes away some of the stress and anxiety during a crisis.  Many people don’t think straight during a crisis, so thinking about what to do before the situation will greatly increase the likelihood of responding appropriately.  This appropriate response can assist the business to recover more quickly from the event.

    Having insurance without a BCP is like driving somewhere you’ve never been at night, without a map or headlights. Business continuity planning and insurance go hand in hand. Ensuring you’ve developed a thorough BCP will help you get back on your feet if you suffer a loss. Proper insurance coverage which includes business interruption insurance can also be an advantage when faced with a loss.


    A good insurance policy will help alleviate some of the financial loss in an emergency, but you cannot expect it to protect you from all possibilities.  In today’s era of instant gratification customers aren’t as understanding as you may think. They will wonder why you weren’t prepared as they expect you to run your business in a timely fashion despite any hiccups.

    Once you have a BCP in place, it’s important to keep revisiting and tweaking it, as risks and potential solutions for addressing them will keep changing over time. By regularly reviewing your risk, you can ensure that, should the worst happen, you are ready to deal with the situation and have a plan in place that will help you resume and not go out of business.

    Here’s a checklist to help:


  • Don't let social media damage your career

    Although social media can open the door to an exciting online community, it has made it harder to separate yourself from your professional life.

    Here’s five tips to help you protect your reputation online.

  • Are you covered for vicarious liability?

    Did you know that you and your business could be held liable for the actions of your employees even if it wasn’t you providing the treatment? As a owner practitioner you are exposed to a multitude of risks on a daily basis. Ensuring you have the right insurance could be the difference between having to cover the financial loss of a claim yourself or being covered by a team of experienced professionals.

    What is the risk?

    Owner practitioners that engage AHPRA registered dental practitioner(s) should ensure they have vicarious liability cover to protect them from claims that originate from treatment provided by their employee AHPRA registered dental practitioners. Some professional indemnity policies are silent or specifically do not provide this cover. This can leave the owner practitioner uninsured and needing to seek their own legal representation and covering any of their own financial loss as a result.

    What is vicarious liability?

    Vicarious liability refers to a situation where someone is held responsible for the actions or omissions of another person. In a workplace context, an employer can be liable for the acts or omissions of its employees, provided it can be shown that they took place during their employment.  

    What you can do to ensure you are adequately covered?

    The impact of vicarious liability on employer dentists can differ and is dependent on the business/ownership structures. It is therefore important to understand both your business structure type and how you hire personnel into your practice as it directly effects the actions of others that you will be held liable for at law. Owner practitioners should seek professional advice from either their lawyer or accountant to understand their own individual circumstances and get clarity on their legal obligations.

    How can Guild help?

    The ADA Dentists Liabilities policy underwritten by Guild Insurance is designed to provide a sleep easy, no gaps cover for these practitioners. The cover includes vicarious liability cover to help ensure that should you and/or your practice receive a demand due to an employee making a mistake or omission, you will be protected from being financially responsible for the legal costs.

    What has changed?

    This year Guild Insurance has changed its pricing approach to practitioners who employ AHPRA registered dental practitioners including dental hygienist and oral health therapists. Practitioners that are currently insured with Guild Insurance should have provided information to us about their professional services at the start of their insurance, during previous renewals and through various surveys. This is the information used to prepare your insurance policy.

    For practitioners that have advised they have an ownership interest in an entity, Guild Insurance will extend cover for owner practitioners and will charge additional premium when there are two or more AHPRA registered dental practitioner employees.


    Download the Dentist Practitioners and Vicarious Liability document to get a complete understanding of the reasons for the changes, the exposures practitioners face when they employ staff and what this means for owner practitioners.


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