Metal fillings’ place in modern-day dentistry

Metal fillings (amalgam) has had its place in dentistry for decades. Dr Marc Sher educates us on the facts and the myths.


Patients frequently ask what should they do with their metal (amalgam) fillings. Mostly, it’s because they’ve read an article that says metal fillings are poisonous and can cause cancer, dementia, Alzheimer’s, and a host of other deadly diseases.

There are also patients, whom have visited a ‘holistic’ health practitioner, and have been advised to remove all their metal fillings. Then, there are patients that simply don’t like the dark shadow they see when they smile or open their mouth.

Whatever the reason, amalgam has had its place in dentistry for decades. It’s important to separate the facts from the myths, and for you to understand the facts to be able to choose the best course of treatment.

What you need to know about metal fillings

Amalgam, a metal alloy, made up of mainly mercury, silver, zinc and copper was the filling of choice for many dentists across the globe for decades. It’s been clinically proven to withstand all the complexities that the oral environment can deliver as well as been shown to last for many years, without wearing down, breaking, or changing its shape.

Amalgam is not moister sensitive (a big issue in the mouth) and it’s condensed into a cavity using the tooth undercuts for mechanical retention. It has a low-cost output for the dentist and a short working time. Which means many dentists have chosen this as a filling of choice to increase production and turnover. There is no wonder that many government dental clinics only offer amalgam as the filling of choice.

Patients more aesthetically demanding

In my 10 years in the dental industry, my personal journey with amalgam has been short. We were taught, and instructed, to place a certain number of amalgam fillings in dental school and had to be fully competent in its application.

We were also taught about resin (white) fillings, but to a much lesser extent. When I left dental school, and entered private practice, naturally I did what I was taught in the beginning. So yes, I was placing amalgam fillings.

As I grew in my role as a private practitioner, I developed a passion for aesthetic dentistry, leading me into the world of tooth-coloured/white fillings. I’ve done research, tried different resin, ceramic and glass ionomer filling materials, and attended courses and workshops learning about their application and function.

As my patients became more aesthetically demanding, I had to make a choice on filling material, and what it basically boiled down to was a simple question, “Why place a metal filling in a white tooth?” The last time I recall placing an amalgam filling was in 2010.

Advances in filling material

As technology and innovation drives the growth and changes in every industry, dentistry has seen a paradigm shift in filling materials. The dental material companies, manufacturing tooth-coloured fillings, have pushed each other to create filling materials that can truly withstand all that the mouth can throw at them.

It’s been a long road, but the science has shown that composite resin, glass ionomers, ceramics and other tooth-coloured materials are a superior choice. There is no reason, other than increased productivity and low-costs, that dentists should turn to an amalgam filling in this day and age.

Technique sensitive

Placing a tooth-coloured filling is extremely technique sensitive; all the steps need to be followed to ensure the correct bonding of the filling to the tooth. There will still be instances where these tooth-coloured fillings will fail, but this is mostly due to poor technique or incorrect material selection. Every other aspect of the tooth-coloured materials we are using nowadays is superior to amalgam.

The difference between amalgam and tooth-coloured fillings

The fundamental difference between amalgam and tooth-coloured fillings is that tooth-coloured materials are ‘bonded’ onto the tooth surface, and metal is not. Metal is held in place mechanically.

What now?

Do you rush to your dentist and have he/she replace all your amalgam fillings? My advice, definitely not! If you have sound, functional metal fillings that do not give you a moments trouble then let sleeping dogs lie.

Unless your dentist has pointed out that there is a health issue (secondary decay), functional issue (broken or chipped), or an aesthetic issue with your amalgam filling, I do not recommend removing them.

Is there scientific proof that metal fillings are poisoning the body?

The short answer is no. Nothing has been clinically proven, and the literature on the topic states that they cannot conclusively prove that amalgams are the cause of said illness. What is known, is that the ‘feel-good factor’ and ‘placebo effect’ have been shown to reign true when it comes to removing metal fillings.

Another important fact is when a dentist picks up his/her drill to remove the amalgam filling, that process completely vaporises the filling into millions of tiny particles. At which time, the patient is at the greatest risk of swallowing and inhaling the harmful metal alloys that the filling contains. Basically, it’s safer in then out.

Removing metal fillings

If you need to have an amalgam filling removed, please request that the dentist places a rubber dam (isolation device) and uses a high-powered suction. This will greatly limit your exposure to debris caused when having an amalgam filling removed.

It is also expected that a tooth will experience some post-operative sensitivity after amalgam has been removed. Most often, the sensitivity is short-lasting and will settle. However, there are exceptions, and removal can lead to further treatment needed on the tooth, such as root canal and a ceramic crown or overlay.

MEET OUR EXPERT - Dr Marc Sher

Dr Marc Sher (B.Ch.D) practices at The Dental Practice in Sea Point, Cape Town, and can be reached via email: [email protected]