If you need a filling, one of the first questions your dentist will discuss with you is what type of filling material to use. The two most commonly used options are tooth-coloured composite resin (white fillings) and silver amalgam, and both have genuine advantages depending on the situation. Understanding the differences between them will help you have a more informed conversation with your dentist and feel confident in whatever decision you make together.
Choosing the right filling is an important part of general dentistry, and the best choice depends on factors including where the tooth is in your mouth, the size of the cavity, your personal preferences, and whether you are being treated under the NHS or privately. There is no single right answer — both materials have a long and successful track record in dentistry.
What Is Dental Amalgam?
Silver amalgam has been used in dentistry for over 150 years. It is a mixture of metals including mercury, silver, tin, and copper. The mercury in amalgam is chemically bound within the alloy, meaning it behaves very differently from pure mercury and is not released in harmful quantities during normal use. Regulatory bodies including the NHS and the World Health Organisation have confirmed that amalgam fillings are safe for most patients, though there are some exceptions (see below).
Amalgam is well known for its exceptional durability. It is hard-wearing, resistant to the heavy forces of chewing, and has a long clinical track record. These properties make it particularly well suited to restoring the back teeth (molars and premolars), which bear the brunt of biting and chewing forces.
What Are Composite (White) Fillings?
Composite resin is a tooth-coloured material made from a mixture of plastic and glass. It is bonded directly to the tooth surface using a special adhesive and light-cured (hardened) in layers. Because composite can be precisely matched to the colour of your natural teeth, it is virtually invisible — an important advantage for fillings in visible areas of the mouth.
Modern composites have improved enormously in strength and durability over the past decade. While they are generally not quite as hard-wearing as amalgam under heavy chewing loads, they perform very well in most situations and are entirely suitable for restoring both front and back teeth.
Comparing the Two Materials
Appearance
This is where composite wins hands down. White fillings are matched to your tooth colour and are effectively invisible to the naked eye. Amalgam fillings are silver-grey and can be noticeable, particularly in teeth towards the front of the mouth. For many patients, aesthetics is the primary factor driving their choice, and composite is the clear preference for visible teeth.
Durability and Longevity
Amalgam fillings are extremely durable and have an average lifespan of 10 to 15 years, with many lasting considerably longer. Composite fillings typically last 7 to 10 years on average, though this varies with the size of the filling, the position of the tooth, and how well you care for your teeth. For large fillings in heavily used back teeth, amalgam may still offer a durability advantage, though high-quality composite and alternative restorations such as ceramic inlays can perform very well in these situations too.
Tooth Preservation
Composite has an advantage when it comes to tooth preservation. Because composite bonds chemically to the tooth, less healthy tooth structure needs to be removed to create retention for the filling. Amalgam is mechanically retained and requires a slightly different cavity shape, which can mean a marginally greater loss of healthy tooth material. Over the lifetime of a tooth, this can be a meaningful consideration.
Safety and Suitability
Amalgam is contraindicated in certain groups: pregnant women, breastfeeding mothers, children under 15, and patients with kidney problems. In the UK, regulations introduced in recent years have already restricted amalgam use in these groups, and there are plans to phase amalgam out of routine dentistry in Scotland and across Europe over the coming years. Composite has no such restrictions and is suitable for virtually all patients.
Cost
On the NHS, amalgam fillings are generally provided as the standard option for back teeth, and composite may only be available NHS-funded in certain clinical situations. Privately, composite fillings typically cost more than amalgam due to the greater clinical time and cost of the material involved. Your dentist will explain the costs applicable to your situation.
Head-to-Head Comparison
| Feature | White Composite Filling | Silver Amalgam Filling |
|---|---|---|
| Appearance | Tooth-coloured, virtually invisible | Silver-grey, visible in the mouth |
| Durability | 7-10 years on average | 10-15+ years on average |
| Tooth removal required | Less (bonds to tooth) | Slightly more (mechanical retention) |
| Suitable for front teeth | Yes | Not recommended (visible) |
| Suitable for back teeth | Yes | Yes (particularly large fillings) |
| Restrictions | None | Not for children, pregnant/breastfeeding women, or those with kidney issues |
| NHS availability | Sometimes (criteria apply) | Standard NHS option for back teeth |
| Cost (private) | Higher | Lower |
What About Replacing Old Amalgam Fillings?
A common question is whether to replace existing amalgam fillings with composite. The answer is: not necessarily. Provided an amalgam filling is in good condition and not causing any problems, replacing it simply for aesthetic reasons means removing healthy tooth structure unnecessarily and may expose the tooth to greater risk of sensitivity or other complications during the procedure.
However, if an amalgam filling is old, worn, cracked, or showing signs of leakage, it may well be appropriate to replace it — and composite is a very reasonable choice in that situation. Your dentist can assess your existing fillings at each check-up and advise you honestly on whether any need replacement.
The Future of Amalgam in Scottish Dentistry
It is worth noting that dental amalgam is being phased out across Europe, including in Scotland, as part of broader environmental and health policy measures. According to NHS information on fillings, guidance on amalgam use is evolving and patients in certain groups are already advised to avoid it. In the longer term, composite and other tooth-coloured materials are expected to become the standard for all dental fillings in Scotland and across the UK.
This does not mean that existing amalgam fillings need to be removed — replacing them unnecessarily would cause more disruption than leaving them in place. But it does mean that when new fillings are placed, composite is increasingly the default choice for most patients.
Getting Personalised Advice
The best choice of filling material depends on your individual circumstances: the tooth being treated, the size and position of the cavity, your medical history, and your personal preferences regarding appearance and cost. Your dentist will discuss these factors with you and recommend the most appropriate option. If you have a preference, make sure to mention it — a good dentist will always take your wishes into account as part of the decision-making process.
If you need a filling or want to discuss your options for dental restorations, we would love to help. At Tarbert Dental Surgery, our experienced team takes the time to explain your treatment options clearly and ensure you feel fully informed before any work begins. To book a consultation or check-up, please call us on 01880 820387 and we will arrange an appointment at a convenient time for you.