Oral Health and Genetic Risk Factors

Fill Me In: The Pros And Cons Of Three Different Tooth Restoration Materials

Having a tooth filled is never a particularly pleasant procedure, but one that is unfortunately necessary for a badly decayed or damaged tooth. Without a proper filling to restore the tooth's strength and integrity, the tooth can damage the teeth and gums around it as it disintegrates. It also presents an easy avenue of infection for bacteria, that can lead to abscesses, pulp necrosis and even blood poisoning in rare cases.

A filling is a relatively simple procedure, but choosing a material to fill the tooth can be challenging, Each material has its own properties making it suitable for filling some teeth and unsuitable for others. Your dentist will advise you on their personal recommendations, but it never hurts to do your own research. With that in mind, here are three of the most commonly used filling materials, and their properties:


This silver compound was the predominant choice of filling material for most of the 20th century, and still the material you're most likely to see in other people's mouths. Made from an alloy of silver, tin, zinc and copper, this is mixed with mercury and injected into the tooth, secured there with dental cement. 

Advantages of choosing amalgam fillings include:

  • Durability: Amalgam fillings are very strong, and you will have no problems chewing with the filled tooth. 
  • Longevity: The average amalgam filling will last for around 12 years before needing repair or replacement.
  • Price: Usually the cheapest available, and because they can be completed on one sitting you need not shell out for repeat appointments.

There are, however, some notable disadvantages:

  • Aesthetics: The dark, metallic colour of amalgam is highly noticeable and somewhat unsightly, and most dentists will recommend alternatives for more visible front teeth. They can also discolour the surrounding enamel as they age and tarnish.
  • Destruction of healthy dentin and enamel: A dentist usually has to cut out some of the healthy tooth remaining after a cavity has been removed in order to cement the filling in place, so amalgam fillings are often larger than those using other materials.
  • Mercury intolerance: Amalgam fillings will not cause mercury poisoning, despite sensationalist reports to the contrary. However, a small amount of people have a lower-than-average mercury tolerance, and will suffer allergic reactions when fitted with extensive amalgam fillings. This can cause a range of neurological problems.

Composite resin

Generally consisting of an inert solid such as silicone mixed with a hard-wearing resin, composite resins are available in a myriad of different formulations, all of which have the same basic properties. These fillings are becoming the standard for most dental restoration procedures.

Advantages include:

  • Aesthetics: Resin fillings are often referred to as 'white fillings', and they do indeed closely match the colour of your natural teeth. A well fitted resin filling is unnoticeable.
  • Tooth strength: Unlike amalgam fillings, resin fillings bond directly to the remaining tooth, strengthening the remaining dentin and enamel.
  • Longevity: A resin filling will last around seven years.

As for disadvantages:

  • Lack of durability: Resin fillings are strong, but they do not hold up well to chewing and direct pressure compared to enamel.
  • Increased cavity occurrence: Resin fillings shrink as they are fitted, and any gaps left between the tooth and the filling are vulnerable to decay. A skilled dentist will avoid this by applying the resin in incremental layers.
  • Cost: White fillings cost significantly more than amalgam. They are also more likely to necessitate costly repeat visits.


Generally speaking these are actually made from alloys with high gold content, but pure gold foil inlays are available if you really feel like splashing out. Long considered the standard for tooth restoration materials due to its excellent wearing characteristics, gold is now waning in popularity.

Advantages include:

  • Durability: Gold does not corrode, and is even more resistant to chewing forces than amalgam. A well fitted gold filling will last several decades, and stands a good chance of never needing repair or replacement.
  • Aesthetics: They're perhaps a little gaudy, but a burnished gold inlay is still much more attractive than a big blob of amalgam.
  • Malleability: Gold fillings are very strong, but retain enough malleability to avoid wearing down the opposing teeth when chewing - excellent if you want to avoid any more fillings.

Disadvantages include:

  • Cost: You knew this was coming. Gold is by far the most expensive option out there.
  • Scarcity: The drop in gold's popularity means that it may be difficult to find a dentist in your area who offers it.
  • Conductivity: Gold fillings conduct heat and cold easily, making them unsuitable for people with sensitive teeth. They also conduct electricity well, meaning that they should never be placed adjacent to amalgam fillings - the static charge the two alloys create can result in painful shocks.

For more information, check out dentists such as Michael Urwand.