Amalgam Removal for Fillings

Dental amalgam restorations had an important role in dentistry for over a century. Renowned for their durability, amalgam fillings often last for decades. We should however be able to recognise their expiry date and consider replacing them due to issues like leakage, crack formation, decay and also concerns about mercury exposure.

The shift away from amalgam restorations is driven by both functional and health considerations. This article explores why amalgam restorations should be replaced, the benefits of ceramic and composite alternatives, and the meticulous process of amalgam removal.

Why Replace Dental Amalgam Restorations?

While dental amalgam has served its purpose well, its inherent drawbacks make it less desirable in contemporary dentistry. Below are the primary reasons why replacing amalgam restorations is often recommended:

1. Leakage – Over time, amalgam fillings are prone to marginal leakage. This occurs when the bond between the filling and the tooth weakens, allowing saliva, bacteria, and food particles to seep into the interface. Leakage can lead to sensitivity, discomfort, and a higher risk of decay. Unlike modern bonded restorations, amalgam does not adhere directly to the tooth structure, which makes it more susceptible to gaps forming over time.

2. Hidden Decay – One of the most concerning issues with amalgam restorations is their tendency to mask underlying decay. Because amalgam is opaque and non-bonded, cavities can develop beneath the filling without being visible on X-rays or during routine examinations. By the time the decay is detected, significant damage may have occurred, often necessitating more extensive treatment like root canals or crowns.

3. Tooth Cracks – Amalgam expands and contracts in response to temperature changes, exerting stress on the surrounding tooth structure. Over time, this cyclical stress can lead to cracks in the tooth. Cracks compromise the integrity of the tooth and may result in pain, sensitivity, or even tooth fractures. In severe cases, the tooth may need extraction.

4. Mercury Exposure – Dental amalgam contains approximately 50% elemental mercury. Although the amount released under normal conditions is minimal, concerns arise from the slow release of mercury vapor during chewing or teeth grinding. Chronic exposure to mercury, even at low levels, has been linked to potential health risks. For patients with mercury sensitivities or systemic health concerns, the removal of amalgam fillings can provide peace of mind and reduce exposure.

The Best Alternatives: Ceramic and Composite Restorations

Modern dentistry offers superior alternatives to amalgam restorations, with ceramic and composite materials leading the way. These materials not only provide functional advantages but also deliver better aesthetics and biocompatibility.

Ceramic Restorations

Ceramic restorations, such as onlays and overlays, are the gold standard for replacing large amalgam fillings. Made from materials like porcelain or lithium disilicate, ceramic restorations are:

• Durable: Ceramic is highly resistant to wear and fracture, making it ideal for restoring large cavities or areas exposed to significant chewing forces.
• Aesthetic: These restorations mimic the natural appearance of enamel, blending seamlessly with the tooth.
• Biocompatible: Ceramic is non-toxic and does not release any harmful substances.
• Preserve Tooth Structure: Onlays and overlays require less removal of healthy tooth structure compared to full crowns, allowing for more conservative treatment.

Composite Fillings

For smaller cavities, composite resin fillings are an excellent alternative to amalgam. Composite materials offer several advantages:

• Bonding Capability: Composite fillings chemically bond to the tooth, creating a tight seal that prevents leakage.
• Aesthetic Appeal: Available in a wide range of shades, composite fillings can be matched to the natural color of the tooth.
• Minimally Invasive: The bonding process allows for conservative preparation, preserving more of the healthy tooth.

While ceramic restorations are ideal for larger restorations, composite fillings are sufficient for smaller areas of decay or wear.

The Amalgam Removal Process

Replacing amalgam restorations requires skill, precision, and proper precautions to minimize mercury exposure. A trained dentist with experience in amalgam removal follows a meticulous protocol to ensure patient safety and comfort.

• Preliminary Assessment – The process begins with a thorough examination of the existing amalgam restoration. The dentist evaluates its condition, the health of the underlying tooth, and the presence of any cracks or decay. X-rays and clinical assessments help determine the extent of treatment required.
• Use of Rubber Dam – A rubber dam is essential during amalgam removal. This flexible sheet of latex or non-latex material isolates the treated tooth, preventing mercury particles, debris, and moisture from entering the mouth. The rubber dam also ensures that the patient does not accidentally swallow amalgam fragments.
• Sectional Removal Technique – Instead of grinding the entire filling, dentists use a sectional removal technique. The filling is divided into smaller pieces using a high-speed dental drill equipped with a water spray. This approach minimizes heat generation, reduces the release of mercury vapor, and shortens the removal time.
• High-Volume Suction – High-volume suction devices are used throughout the procedure to capture mercury particles and vapor at the source. These specialized suction systems help maintain a safe environment for both the patient and the dental team.
• Protective Measures – In addition to the rubber dam and suction, other protective measures may include: Providing the patient with an oxygen mask to prevent inhalation of mercury vapor. Using personal protective equipment (PPE) for the dental team, including masks and gloves. Employing air filtration systems to maintain clean air in the treatment area.
• Restoration Replacement – Once the amalgam filling is removed, the dentist carefully cleans and prepares the cavity. If decay or cracks are present, they are addressed before placing the new restoration. Depending on the size and location of the cavity, the dentist will select a ceramic onlay/overlay or a composite filling to restore the tooth’s strength, function, and appearance.
• Post-Procedure Care – After the procedure, the dentist provides instructions for post-treatment care. Patients may experience mild sensitivity, which typically subsides within a few days. Maintaining excellent oral hygiene and attending regular check-ups will help ensure the longevity of the new restoration.

The Importance of Choosing an Experienced Dentist

Amalgam removal is a complex procedure that requires advanced skills, specialized equipment, and attention to detail. It is essential to choose a dentist with expertise in safe amalgam removal techniques to minimize risks and achieve optimal results. Dentists who follow protocols recommended by organizations such as the International Academy of Oral Medicine and Toxicology (IAOMT) ensure that the procedure is performed safely and effectively.

Conclusion

Although dental amalgam restorations have a long history of success, their limitations and potential risks make them less favorable in modern dentistry. Issues like leakage, hidden decay, tooth cracks, and mercury exposure highlight the need for replacement. Advanced materials like ceramic onlays and overlays, along with composite fillings, offer superior durability, aesthetics, and biocompatibility.

The process of amalgam removal requires precision, skill, and proper safety measures to protect patients from mercury exposure. By choosing a qualified dentist and exploring state-of-the-art restorative options, patients can achieve healthier, more attractive smiles while addressing the shortcomings of outdated amalgam restorations. Replacing amalgam is not just a functional upgrade—it is an investment in long-term oral health and overall well-being.