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Fillings

Amalgam Fillings

I am sure I am not alone in remembering playing with liquid mercury in science classes at school (probably more years ago than many of us care to remember.) However it is very toxic and is handled with much more care nowadays. It was used extensively in the hat-making industry, which was prevalent around the south Manchester area. Its toxic effect on the brain led to the expression "As mad as a hatter". It is notable that Stockport County football team is still referred to as "The Hatters"; it could be argued that you were also mad to support them!

The dental amalgam controversy refers to the conflicting views over the use of amalgam as a filling material mainly because it contains the element mercury. Scientists agree that dental amalgam fillings leach mercury into the mouth, but studies vary widely in the amount and whether such amount presents significant health risks. Estimations run from 1-3 micrograms (μg) per day up to 27 μg/day. The effects of that amount of exposure is also disputed,. The use of mercury in dental fillings is approved in most countries.Norway,Denmark, andSwedenhave banned the use of mercury in dental amalgams over environmental concerns. It is estimated that crematoria release up to 16% of theUK's total mercury emissions due to the release of mercury from fillings during cremation. Crops grown near crematoria have been shown to have increased mercury levels. In 2005 Defra introduced a requirement for the cremation industry to remove mercury from 50% of cremations. The national target, based on the available science, achieves a proportionate response for removing mercury from cremations, whilst not burdening the bereaved with excessive cost and the possibility of closing of local crematoria.

Elsewhere in the world, unused dental amalgam after a treatment is subject to strict disposal protocols, again for possible environmental reasons rather than over fears of direct toxicity to humans.

Those who advocate the use of amalgam point out that it is durable, relatively inexpensive, matched many physical properties of natural tooth enamel and easy to use. Indeed if a filling involves the biting surface of any tooth behind the canines, the terms and conditions of the NHS prevent a dentist from placing anything other than mercury-containing amalgam*

Recent international meetings reached an agreement to phase out the use of mercury in dentistry, but it has largely been left up to each individual country to set its own timetable in this regard.

Whichever side of the argument you come from, there is little doubt that if mercury-containing fillings were invented today, they would be banned before the initial trial stage.

At King Street Dental Practice we offer mercury-free alternatives. Just ask.

However even where we do use amalgam filling materials we use a high-silver containing type which has great handling characteristics and is specifically formulated to give a more durable and (on average) longer-lasting restoration.

*[very small areas of decay can be restored using a white filling with sealant on the NHS]

Composite Fillings

Over the last century there have been many attempts at developing dental fillings which give a more natural (tooth-coloured) restoration than amalgam, or gold which preceded it.

Today the commonly used "white filling" material is composite resin. This material is basically a plastic with microscopic particles of glass suspended in it. As with amalgam, there are different composites with a range of qualities and physical properties of this material. This means that there is a range of prices from the manufacturers to match a range of physical properties.

Without getting too bogged down on technicalities, a lot of research and development has gone into composite filling materials since they were first introduced in the 1970s. Generally speaking the more expensive the materials, the better their properties:

So what are the advantages and disadvantages of composite fillings vs. mercury amalgam?

Advantages

Disadvantages

Again, similar to amalgam, in general the financial constraints of the NHS regulations often limits the dentist's choice towards the cheaper end of the range, while outwith the NHS constraints, a dentist has more freedom to choose from the whole range of these materials and techniques of use. It should also be borne in mind that under NHS regulations it is illegal for a dentist to place anything other than mercury amalgam in adult teeth, if the filling involves the biting surface of any tooth behind the canines.