- Tony
Hot Topics in Dentistry: MMIs- part 2
Updated: Jul 12, 2021
Amalgam
Sugar Tax
Fluoridation
Amalgam

Amalgam is a commonly used mixture of metals for filling teeth. It's usually made from mercury with some other metal like nickel.
Cons:
Mercury is the most toxic non-radioactive element to humans
No barrier in the body is impermeable to mercury, not even the blood brain barrier
Small amounts of Mercury vapour is released by amalgam fillings daily
One molecule of mercury can kill nerve cells
Mercury has environmental problems
Aesthetics (composite fillings look better)
More tooth structure needs to be removed (shift towards minimally invasive dentistry)
May lead to discolouration of surrounding teeth
Teeth may fracture with cooling of the hot liquid
Pros:
Easier to use than composite fillings
Shorter appointment times
Fewer visits
Research shows it is 'safe'
Durable and inert
Relatively cheap
Sugar Tax

The tax was first introduced for soft drinks in Mexico as measure to reduce the childhood obesity epidemic.
Pros:
In the first year, there was a 12% decrease in quantity of soft drinks purchased in Mexico.
The extra revenue generated by the tax can be used usefully
Fruit and veg
Education
Healthcare
Largely supported
Pillars of ethics: beneficence
The government has a moral obligation to care for the population
Will also reduce tooth decay, diabetes and other disorders
Which will reduce pressures on healthcare systems
Cons:
Disproportionately affects poorer people
Equality?
Autonomy?
Soft drinks can help people with diabetes
The number of soft drinks purchased in Mexico has risen
Calls to elevate the tax
Slippery slope of taxes increasing and soft drinking becoming out of reach for some
There are other causes of obesity and focusing on these (eg education) is a more effective way to reduce it.
Fluoridation Fluoride is sometimes put into water systems in order to prevent tooth decay (toothpaste also contains fluoride.) Don't be confused with chlorination. Chlorination is meant to kill bacteria. Pros:
Everyone drinks water so this does not favour certain subsets over others (eg poor vs rich)
Effective in inhibiting tooth decay
Fluoride binds to tooth enamel, reducing its solubility in acid
Cons:
Ethics
Some people don't know there is fluoride in water
Does not respect autonomy
There are side effects such as dental fluorosis
This is the mottling of teeth
Although it is a purely aesthetic problem