During their lifetime, UK adults have on average 8 fillings as result of poor oral hygiene and tooth decay. Modern dentistry provides the cosmetic choice of white fillings, but do they stand the test of time?
Early 19th century breakthrough
Prior to the breakthrough of amalgam fillings in 1819, the common lack of oral hygiene meant many of our ancestors had to endure the unpleasant symptoms caused by tooth decay, which often led to multiple tooth loss. Drilling away the damaged surface of a tooth and sealing it with a protective filling became common practice by dentists across the world and remains to this day.
The materials used for fillings have traditionally been either precious alloys (such as gold, platinum, palladium), non-precious alloys (such as nickel or cobalt chromium) and amalgam alloys (combining mercury, silver and tin). As well as being cheap and readily available, these amalgam fillings were highly effective and became the material of choice.
For the past few decades the benefits of amalgam fillings have become a controversial subject of discussion in the media, with stories recounting many adverse or damaging effects from the presence of mercury in the mouth. Many of these articles site examples of side effects including: headaches, chronic fatigue, allergies, depression and go on to link mercury fillings as causes for Alzheimer’s disease, Parkinson’s disease, diabetes, cancer, immunological dysfunction and early death.
There is no dispute about the deadly toxicity of mercury, but the foundation of these stories was born from the evidence that dental amalgam releases tiny amounts of elemental mercury. This is either inhaled or partially enters the body through swallowing and is eventually excreted by the kidneys. The levels of this mercury vapour released into the body from fillings is minute compared with other sources such as contaminated oily fish from the North sea.
Many of the stories in the press also refer to the ban of mercury fillings in Sweden, but this has been taken out of context. It was not due to health concerns with dentistry but for environmental reasons to reduce the industrial exposure and environmental contamination, in general, of heavy metals.
Dentistry only accounts for less than 0.1% of heavy metals used compared with other industrial sources such as the extraction of gold from ore, glass production, long-life battery production, and now the production of long-life electric bulbs. The Swedish ban includes use of mercury in dentistry but is not made as result of concerns with amalgam fillings in teeth.
Science vs Scaremongery
Since 1840 there have been 4 major international reviews of the safety of mercury amalgam fillings and each time the results show no systemic disease has been attributed to the use, insertion or removal of mercury in teeth. The few cases in which there were reactions to amalgam fillings were attributed to some of the constituents from the amalgam fillings that didn’t necessary contain mercury (ie silver, tin, or copper). The continued use of amalgam fillings has been endorsed by both the British Dental Association & the American Dental Association.
Amalgams are incredibly durable and in most cases will successfully protect a tooth for over 20 years. Alternatives to amalgams are available and used for cosmetic reasons (to match the colour of the patients teeth) but invariably fail and break after only 3-5 years.
There is an increased risk of higher exposure to mercury vapour during the installation or extraction of fillings but common procedures to protect the patient have been established for many years.
It is my view that any patient or practitioner who attributes any systemic disease to the use of amalgam fillings is wholly misguided and has been misinformed. Any practitioner who suggests or implies that a systemic disease may be influenced by the removal of amalgam fillings should find themselves before a Disciplinary Committee at the General Dental Council.