Your dentist has offered you a choice: a white composite filling or a silver amalgam one. You have heard that silver fillings last longer and are more durable. Is that true? And if so, does it matter?
These are fair questions. The filling material debate has been ongoing for years, and both sides have genuine merits. Here is what the evidence actually supports — so you can make a genuinely informed choice.
What Each Type Is Made Of
Silver amalgam fillings are made from a mixture of metals including mercury (about 50%), silver, tin, and copper. The mercury binds the metals together into a durable filling material. They have been used in dentistry for over 150 years.
Composite fillings are made from a resin matrix mixed with fine glass or ceramic particles. They are placed as a soft putty and hardened with a blue light. The result bonds directly to the tooth structure.
Durability: What the Evidence Shows
Amalgam fillings do have a longer track record and historically demonstrated exceptional durability, particularly in back teeth where chewing forces are highest. Average lifespan studies have often shown amalgam lasting 10-15 years or more.
However, modern composite materials have improved dramatically. Contemporary composites properly placed in appropriate situations now show comparable survival rates to amalgam in many studies — and in some cases, longer. A 2019 review in the Journal of Dental Research found composites performed well in posterior teeth, though amalgam still held an edge in large restorations in heavy grinders.
The Bonding Advantage of Composite
One genuine advantage of composite that does not show up in simple durability statistics is its bonding ability. Composite bonds directly to the tooth structure, which can actually support and reinforce the remaining tooth. Amalgam sits in the cavity like a wedge — it does not bond to the tooth.
This means teeth with large composite fillings may be less likely to crack over time compared to those with amalgam, because the filling actively holds the tooth together rather than pressing outward.
The Mercury Question
Some patients have concerns about mercury in amalgam fillings. The scientific consensus — from the FDA, WHO, and numerous dental associations — is that mercury in amalgam is bound in a stable form and poses minimal health risk at normal exposure levels. Millions of amalgam fillings have been placed with a strong safety track record.
That said, if you have a specific health concern or preference to avoid mercury, composite fillings are a perfectly viable alternative. The evidence supports their safety and effectiveness.
When Amalgam Still Makes Sense
In very large cavities, in patients with heavy grinding or clenching habits, or where moisture control during placement is difficult, amalgams mechanical properties may give it a practical edge. Your dentist will tell you if there is a specific clinical reason to prefer one material for your situation.
Making Your Choice
For most patients in most situations, modern composite fillings are a strong, lasting choice that also look better and support the remaining tooth structure. The "silver lasts longer" argument is increasingly outdated given material improvements.
Your dentist can advise on what is best for your specific tooth and circumstances. The most important thing is not leaving decay untreated — whatever material you ultimately choose.
Call 01323 723757 or book at www.meadsdental.com
Meads Village Dental Practice