Your Guide To Dental Cavities – Filling In The Gaps

Have you ever been asked by a friend or colleague how many fillings you have? Whilst the nation’s dental health is undeniably improving, our patients and the general public alike still use the number of fillings as a gauge to measure dental health.

What’s important to recognise is that even patients who visit their dentist regularly may experience a dental cavity, which could result in a filling. One of the biggest culprits, even for those who typically practice exceptional oral hygiene, are those difficult-to-reach places in between your teeth that can easily go undetected.

In this month’s blog, our London-based dentist takes an in-depth look into dental cavities and fillings.

Fillings - The Dental Centre London

What is a dental cavity?

A dental cavity forms when the outer surfaces of your teeth are attacked by acid-producing bacteria. The bacteria produce acid as they digest the sugar in your diet. The cavities can become larger as more bacteria sit in them, producing more and more acid.

In the beginning, small cavities may have no pain as they are on the outer surface of the tooth. As they deepen and get closer to the nerve, your teeth may become more sensitive whilst eating or drinking. Hot or cold food/drink can certainly exacerbate the problem.

What is a dental filling?

A filling is simply filling up a cavity with a suitable material. Your dentist will remove any decay and then fill the cavity back up to the original contour of the tooth.

What do they fill cavities with?

The exact material used to fill a cavity depends upon various factors:

  1. The size of the cavity
  2. The location of the cavity
  3. The philosophy of the dental practice; some practices prefer not to use amalgam filling as it contains mercury.
  4. Affordability

What is a filling made of?

Depending on the criteria listed above, there are a variety of filling materials which can be used. Your dentist will review the options available and make a recommendation based on your personal criteria.


This is a malleable metal alloy containing mercury. It has been shown to be extremely durable as a dental filling material and lasts many years. Some patients comment that it is not particularly attractive and there are certainly more aesthetically pleasing solutions/materials available.


Gold is virtually inert and is well tolerated by the body. Its highly polished surface closely matches the surface of dental enamel when viewed microscopically. For the patient, this means it does not wear down the opposing teeth and can be considered a highly biocompatible material.

Whilst many individuals appreciate how gold looks, it does not look very natural once in situ within the mouth. Some people prefer to opt for a more natural-looking filling.

Direct Composite using Dental bonding

Your dentist can also use a tooth-coloured composite material to pack into the cavity once the diseased area has been removed. This has the advantage of being highly aesthetic and also highly convenient as it can be placed in one appointment. Composites can discolour over time so your filling may need to be replaced more often.

>> Further reading on dental materials

The cavity-filling procedure

The procedure for having a cavity filled depends on the material being used. As a guide, most procedures follow this format:

  1. a patient or dentist will notice the cavity and both parties will agree that action needs to be taken
  2. your dentist will examine the cavity and discuss the options available (and associated solutions, time frames and prices)
  3. a decision regarding material is agreed upon and the dentist will prepare the cavity accordingly
  4. if your treatment consists of direct composite, the composite material will be placed directly. Alternatively, your dentist will take an impression of the prepared cavity and place a temporary filling into position. The impression will be sent off to a dental laboratory so a new restoration can be manufactured – a lab-made composite.
  5. if you had a dental bonding composite filling then step 4 is your final stage. If a dental laboratory is manufacturing your filling, expect this to be returned approximately 2 weeks later. This will then need to be fitted by your dentist
  6. a review of your filling will take place at your six-monthly check-up at the dentist.

Tooth cavity fillings at home


Cavity filling kits are available in various pharmacies and online. Whilst they may seem like a cheap and convenient option, they should never be considered a permanent solution.

Why is this? Whilst home kits may well fill the cavity, the chances are you will be filling over bacteria which will continue to cause dental decay underneath. More worryingly, you may not notice this decay until it has reached the nerve of your tooth. This will cause greater discomfort in the long term and may potentially result in a more expensive dental procedure like root canal treatment.

If you need to use a tooth cavity filling at home, only consider this as an emergency repair option. Always make an appointment to visit your dentist within the next fortnight.

Preventing dental cavities


The old saying rings true – prevention is better than cure. Please follow our four simple steps to help reduce the risk of dental cavities:

  1. clean your teeth twice a day for a minimum of two minutes (always using a fluoride-releasing toothpaste)
  2. clean between your teeth with an interdental brush or use floss
  3. use a fluoride mouthwash after meals but NOT after brushing
  4. visit your dentist regularly as they will be able to detect the small cavities in places which won’t always be visible to you.

By following these steps, and by visiting your dentist regularly, it is possible to keep the cost of dentistry down and ensure your teeth remain fit and healthy for life.

If you live in the Euston area of London and require a dentist to help you with your dental health, dental hygiene or to check for dental cavities then please give The Dental Centre London a call on 020 7679 7186