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  • Writer's pictureRahul Monga

Class 2 Amalgam Restoration for NDECC and Australian Dental Council Practical Exams

Updated: May 12

Are you an internationally trained dentist aspiring to obtain your license in Canada, New Zealand, USA, or Australia through exams like the NDECC and Australian Dental Council Practical Exam? Welcome to the world of international dental licensing exams, where Class 2 Amalgam Restoration is a fundamental skill you must master. In this blog, we will guide you through the essentials of Class 2 Amalgam Restoration, discuss what could go wrong if each step of the procedure is not performed well, and provide you with valuable insights to help you ace your exams.

Understanding Class 2 Amalgam Restoration

Class 2 Amalgam Restoration involves the repair of a specific type of dental cavity that occurs between two teeth. In this procedure, you'll be tasked with restoring a pre-prepared tooth with an amalgam filling. To excel in this procedure, you need to comprehend tooth morphology and the intricacies of the restoration process.

Key Concepts and Terminology

Let's delve into the technical details, including terminology and concepts:

- Tooth Morphology: Before you begin, gain a deep understanding of tooth morphology, including oblique ridges, triangular ridges, cusps, and the central fossa. You must recognize how these structural components impact the overall tooth anatomy.

- Matrix Bands: Matrix bands, like the Tofflemire , play a pivotal role in the restoration process. They are designed to create a temporary wall that shapes the amalgam during placement. It's vital to select the appropriate band thickness and ensure a precise fit for effective sealing of the proximal box area.

- Wooden Wedges: These small wedges are indispensable for maintaining proper embrasure space during the procedure. They provide support and stability, preventing unwanted material leakage.

- Instrumentation: The choice of instruments can significantly impact the quality of your amalgam restoration. Key tools include amalgam carriers, condensers, Cleoid discoid carvers, Tanner, IPCs (Interproximal Carvers), and Hollenbeck Carvers.

The Restoration Procedure: A Technical Deep Dive

Now, let's walk you through a detailed Class 2 Amalgam Restoration procedure and explore what could go wrong at each step:

1. Matrix Band Placement: If the matrix band is not positioned correctly or doesn't create a tight seal, amalgam may leak, leading to marginal gaps. This can result in recurrent decay, sensitivity, and poor aesthetics. The outcome might look like an ill-fitting, uneven filling that doesn't blend seamlessly with the natural tooth.

2. Condensation: Insufficient condensation can leave voids within the amalgam, affecting its durability and resistance to fracture. Inadequate pressure during condensation can lead to voids and less effective sealing. The filling may look porous and lack structural integrity.

3. Margin Refinement: Neglecting to refine margins properly can cause overhangs or gaps. These can trap food particles and bacteria, leading to recurrent caries, discomfort, and gum inflammation. The outcome could be an unstable filling with visible gaps along the margins.

Common Challenges in Margin Refinement:

A. Overhangs or Gaps: Inadequate margin refinement can result in overhangs or gaps between the amalgam filling and the tooth structure. Overhangs, where excess material extends beyond the cavity margin, create niches that trap food particles and bacteria. This not only compromises oral hygiene but also increases the risk of recurrent decay. On the other hand, gaps expose vulnerable areas, leading to sensitivity and potential inflammation of the gums.

B. Suboptimal Contact Points: The restoration's contact points with adjacent teeth must be precisely contoured. If margin refinement is neglected, irregular contact points may emerge. This can disrupt the natural alignment of teeth, affecting occlusion and overall functionality. Patients may experience discomfort, and the restoration may stand out visually, impacting the aesthetics of the dental work.

How Poor Margin Refinement Manifests:

- Visual Discrepancies: A poorly refined margin is visually apparent, affecting the overall appearance of the restoration. Overhangs or gaps may create irregularities that are easily noticeable, diminishing the quality of the dental work.

- Functional Implications: Suboptimal margin refinement can result in improper contact points, affecting how the teeth come together during biting or chewing. This can lead to discomfort for the patient and impact their ability to eat normally.

- Hygiene Challenges: Overhangs and gaps become havens for plaque accumulation, making it challenging for patients to maintain proper oral hygiene. This can contribute to further decay, gingivitis, and other oral health issues.

Best Practices for Margin Refinement:

a. Use of Explorers and Probes: Dental explorers and probes play a vital role in evaluating the margins post-restoration. These instruments help identify any irregularities, overhangs, or gaps that may require further refinement.

b. Finishing Burs and Strips: Utilizing fine finishing burs and strips aids in achieving smooth, polished margins. This step ensures that the restoration seamlessly integrates with the natural tooth structure, both visually and functionally.

4. Contouring: Inaccurate contouring can result in an unnatural appearance, with the restoration standing out against natural teeth. It may also lead to poor occlusion and impaired functionality. The filling may appear bulky and misshapen.

5. Interproximal Carving: Poorly carved interproximal contours can affect the overall esthetics of the restoration, making it evident that dental work has been done. This can reduce patient satisfaction and confidence. The outcome may look unnatural and out of place.

6. Finessing: If you don't pay attention to the final details and finishing, the restoration might have a rough, uneven surface, making it harder to clean, and potentially leading to staining and discoloration over time. The final result may appear unpolished and rough.

Tips for Success in Licensing Exams

- Practice Diligently: Skill development in Class 2 Amalgam Restoration comes with practice. The more you practice, the more confident and precise you'll become.

- Learn from Experts: Consider seeking guidance from experienced instructors or taking specialized courses to enhance your skills. Their insights can be invaluable.

- Respect Dental Anatomy: Your goal isn't to impose your version of dental anatomy but to replicate the natural tooth structure accurately.


Class 2 Amalgam Restoration is a fundamental skill that all internationally trained dentists aiming to secure their licenses in Canada, New Zealand, USA, or Australia through exams like NDECC and the Australian Dental Council Practical Exam must master.

Tooth morphology, proper use of instruments, and precise techniques are the keys to success in these exams. With dedication and practice, you can confidently approach the restoration procedure and achieve excellent results.

Good luck with your journey toward becoming a licensed dentist in your chosen destination! For more dental exam tips and guidance, stay tuned to our blog.


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