Most people don’t give much thought to what goes into a filling until they’re sitting in the chair and the dentist asks which type they’d prefer.
White fillings, more formally known as composite resin restorations, have become the default choice for the vast majority of patients at dental practices across Scotland. If you’re exploring your options for dental fillings in Dreghorn, it’s worth understanding what composite actually is, how it differs from the older silver amalgam, and when each material might be the right choice for your tooth.
What a White Filling Actually Is
Composite resin is a mixture of a plastic base material (typically a compound called bis-GMA) and finely ground glass or quartz particles. The result is a tooth-coloured paste that can be shaped to fill a cavity, then hardened in place using a blue LED curing light. According to Wikipedia’s overview of dental composite materials, this light triggers a chemical process called polymerisation, which transforms the soft material into a durable solid restoration. The whole thing takes longer than placing an amalgam filling, but the end result blends with the surrounding tooth in a way that amalgam simply can’t manage.
That matters more than most patients initially realise.
The Case for Amalgam, and Why It’s Declining
Amalgam isn’t going anywhere quite yet, but its days as the go-to restorative material are largely behind it. The silver-coloured alloy (a mix of mercury, silver, tin, and copper) has been used in dentistry for over 150 years. It’s hard-wearing, relatively quick to place, and handles the biting forces on back teeth well. In our experience, amalgam restorations placed correctly can last twenty years or more without any issues at all.
But there are real limitations. The main one is that amalgam doesn’t bond chemically to tooth structure; it just sits in the cavity. This means more healthy tooth has to be removed to create the mechanical shape that holds the filling in place. Over time, amalgam also expands and contracts slightly with temperature changes, and in some cases this contributes to small fractures in the tooth around the restoration.
You’ll find articles online suggesting amalgam and composite perform identically over the long term. In our experience, that’s not quite the whole picture. The conservation of tooth structure with composite is a genuine clinical advantage, particularly for smaller cavities.
A Direct Comparison of the Two Materials
Here’s a summary of the main differences between white composite and amalgam fillings:
| Feature | White Composite Filling | Amalgam Filling |
|---|---|---|
| Appearance | Tooth-coloured, blends naturally | Silver/dark grey, visible in the mouth |
| Bonding | Chemically bonds to tooth structure | Mechanical retention only |
| Tooth removal needed | Minimal, preserves more healthy tooth | More tooth removed to create retention shape |
| Setting method | Cured immediately with blue LED light | Hardens gradually over hours |
| Average lifespan | 7 to 12 years (varies by size and location) | 10 to 20+ years in ideal conditions |
| NHS availability in Scotland | Front teeth only; back teeth are usually private | Available on NHS for posterior teeth |
| Mercury content | None | Contains stabilised mercury alloy |
Worth noting: the EU has phased out amalgam for children under 15, pregnant women, and breastfeeding mothers. Scotland follows this guidance. For a broader overview of dental treatments available under NHS Scotland, NHS Inform’s dental treatments page covers the main options and what patients can expect to pay.
The Mercury Question
It comes up in almost every consultation. Patients want to know whether amalgam is safe, given that it contains mercury, a substance they associate, not unreasonably, with toxicity.
The short answer is that dental amalgam uses mercury in a stabilised alloy form, not the pure liquid mercury that causes neurological harm. The scientific consensus, including guidance from the World Health Organisation, has consistently been that amalgam restorations are safe for most adults. That said, the direction of travel in dentistry has clearly moved away from it, partly because of environmental concerns about mercury disposal, and partly because composite has improved so dramatically over the past two decades.
Actually, the bigger practical concern for most patients isn’t safety at all. It’s aesthetics. Nobody wants a dark patch visible every time they smile or speak.
When Amalgam Might Still Be the Right Choice
Honestly, amalgam is used less and less often these days. But there are situations where it remains a reasonable clinical option:
- Very large cavities in back teeth, where composite shrinkage during curing could compromise the restoration
- Patients with certain allergies to components in composite resins (rare, but it does occur)
- Clinical areas with very poor moisture control, where reliable composite bonding is difficult to achieve
- NHS treatment on posterior teeth in adults aged 26 and over, where back-tooth white fillings are not routinely funded
Some patients find composite completely straightforward. Others, particularly those with very deep cavities or heavily broken-down teeth, may find that a different type of restoration entirely, such as an inlay or a crown, is the more appropriate route.
What to Expect if You Choose a White Filling
We had a patient come in not long ago who’d been putting off treatment for months because she assumed the filling would be clearly visible. She had a moderate cavity on an upper premolar, right in the smile zone. The composite was shade-matched to the surrounding tooth, placed and cured in a single visit. When we handed her the mirror at the end, she genuinely couldn’t point to where the tooth ended and the filling began.
That’s not achievable in every case. Very large restorations in back teeth sometimes have visible margins, and heavily loaded areas can show wear over time. But for most cavities of average size, composite placed carefully by an experienced clinician is essentially invisible.
Look, the real reason composite has become so dominant isn’t clever marketing. It’s that patients see the result once and immediately understand why amalgam is fading out.
Costs and NHS Access in Scotland
Under NHS Scotland, dental examinations are free for everyone regardless of age. For treatment itself, patients under 26 receive free care. Adults aged 26 and over pay 80% of the cost, capped at £384 per course of treatment. Back-tooth white fillings are typically classed as a private treatment under the NHS in Scotland, which means amalgam is the funded option for posterior teeth in adult patients.
Privately, white composite fillings typically cost somewhere between £80 and £200 per tooth depending on size and complexity, though fees vary between practices. For many small to medium cavities, the actual cost difference between NHS amalgam and private composite isn’t as substantial as patients assume, particularly once the 80% NHS contribution is taken into account.
And here’s something most people don’t expect: when you factor in the preservation of tooth structure and the potential to avoid more expensive treatment further down the line, composite often represents the better long-term value.
If you’d like to talk through your options for tooth-coloured fillings, our team at StormDental in Dreghorn is happy to help. We can often advise over the phone whether a private composite filling or NHS amalgam is the more sensible route before you even come in. Call us on 01294 218733 and we’ll point you in the right direction.
