Dental Amalgam (Mercury, Silver)

This is an area where there are a number of viewpoints which are diametrically opposed. The current mainstream and official New Zealand Dental Association opinion is that they still are extremely useful filling materials. Recently there has been a global shift in opinion relating to the use of mercury, there are serious attempts to decrease the dependence on mercury mainly due to its environmental impact. Mercury is in fact banned for dental use in Norway, Denmark and Sweden amongst others. As of 2018 all 28 EU member countries have voted to make it illegal to place amalgam mercury fillings in children up to 15 years of age or pregnant and lactating women. In countries where its use is allowed there are recommendations to restrict the use in pregnant and renal (kidney) compromised patients. It is a quirk that amalgam is considered toxic before, during and after removal. However mercury is considered safe in the mouth bound as an amalgam alloy.

Intergovernmental Treatment on Mercury (and Dental Amalgam) - March 2013

In early 2009 the United Nations Environment Programme (UNEP) agreed on the need to develop a global legally binding treaty on mercury. Governments were tasked with negotiating a treaty through a series of five conferences called Intergovernmental Negotiating Committee (INC) meetings. Beginning in 2010 they were concluded in January 2013. The last of the meetings, which brought together over 140 countries, resulted in a global legally binding treaty on mercury. This wide ranging agreement aims to reduce mercury emissions and releases to the air, water and land.

The UNEP treaty on mercury is highly relevant to oral health, as it will include provisions for dental restorative materials, specifically dental amalgam.

The treaty, just announced, is known as the Minamata Convention and will be signed in Minamata (Japan) later this year. It will enter into force once it has been ratified by 50 countries. This will regulate a range of areas, including the use of mercury in products and industrial processes. The treaty requires countries with coal fired power plants to install filters and scrubbers on all new plants and to commit to reducing emissions from existing operations to prevent mercury from coal reaching the atmosphere. The treaty requires governments to draw up national rules to comply and could take between three and five years to take effect.

Intergovernmental Treatment on Mercury (Dental Amalgam)

  • Intergovernmental Treatment on Mercury (Dental Amalgam)
  • Global Mercury Assessment
  • Mercury – Time to Act

A summary of the various opinions against the use of mercury in dental fillings is as follows:

  • Mercury and silver fillings (amalgam) have been used for many years
  • Although the mercury is bound in the fillings it still releases vapours in the mouth. There are detectable concentrations of intra-oral mercury vapour in the region of 1 to 5 ug per m3 which increase with chewing and raising the temperature of the fillings (i.e. food and drink above body temperature)
  • It is this mercury vapour which causes a problem in patients who are susceptible to it. When it is inhaled, it crosses the blood gas barrier in the lungs and is transported around the body by the blood, when it reaches the head it crosses the blood brain barrier.
  • This can cause a multitude of symptoms in susceptible patients
  • I am extremely fortunate to have been working with Dr Damian Wojcik for many years, a medical practitioner who has had a special interest in this area of medicine
  • I feel uncomfortable removing mercury fillings in patients who don’t need them replaced
  • I have and do feel quite happy to delegate the diagnostics of which patients need their fillings replaced, to someone medically qualified and who is applying an objective methodology to evaluating the patient needs.

The methodology I use in conjunction with Dr Wojcik is as follows:

  • All patients who consult me for amalgam removal are advised to see Dr Wojcik to determine if they have symptoms which are severe enough to warrant treatment
  • Dr Wojcik administers a subjective symptomatic questionnaire of 110 questions; these are ranked on a scale of 1-3. These are then evaluated and totalled
  • In addition the number of surfaces filled with amalgam are recorded and totalled
  • Additional tests are undertaken if needed, these are;
    • Intra-oral mercury vapour levels are measured with a Jerome 405 mercury analyser (typically 0 – 89 mcg/m3 for a sample of 700 patients).
    • Toxicology tests such as the 6 hour DMPS urine mercury challenge test to assess levels of mercury in the soft tissues of the body.
  • Dr Wojcik has screened over 3400 patients in this manner over the last 16 years. He has a sub-group of 240 patients with 0 amalgams which acts as a control group. The average symptom score of this group is 35. The rest of the patients show a dose related response of symptoms to the number of surfaces filled. This has a statistically significant correlation of p < 0.001 i.e the greater the surfaces or amount of amalgam, the greater the symptoms.
  • Patients who have a symptom score of > 65 start becoming aware of their condition.
  • Safe protected removal of the amalgams together with mercury detoxification sees this symptom score drop down to a level comparable with the nil ever amalgam control group. Patients diagnosed with chronic mercury toxicity from their amalgams who choose not to be treated remain unwell with little change in their symptom scores, compared with the fully treated group. The difference is clinically relevant and statistically significant (p < 0.001). The benefits following treatment are long lasting and persist for at least 15 years. Dr Wojcik has presented this research at medical forums in Australasia, and has also been invited to present at the NeuroTalk neurology congress in Barcelona Spain, May 2017. He is in the process of writing his research for publication.
  • On a personal level, I have sent Dr Wojcik many patients with a large number of mercury fillings whom he has tested and confirmed do not need any treatment, apart from selenium 150 mcg/day to bind and inactivate mercury, and regular daily maintenance vitamin C 3 G/day to improve anti-oxidant levels. This is particularly true in older patients with a low mercury symptom scores where the expense and dental intervention is not warranted. The APO-E genotype blood test previously available to pinpoint those patients susceptible to the neurotoxic effects of mercury (and lead), is not currently available in the Auckland and Northland regions.
  • I feel that for me, this constitutes an ethical approach to analysing and dealing with this difficult problem of diagnostics
  • I am quite happy to remove amalgam restorations in a manner which avoids a large intake of mercury, and then replace the amalgam restoration with composite, ceramic and zirconia restorations
  • Please call us on 09 438 7694 to set up a consultation if you think we could be of assistance to you