When restoring a cavity, we need to design the cavity correctly for the restorative material that we are choosing to use. With any cavity, there are basic principles of design that we need to consider:

• Removal of all active caries
• Removal of any weakened tooth structure
• Ensure margins are easy to access and clean

When considering amalgam cavity design, we have to appreciate the properties of amalgam:

• Amalgam is non-adhesive – it needs to be mechanically retained in the cavity
• Amalgam is brittle in thin sections – a minimum depth of 2mm is required to minimise failure

You can learn more about amalgam as a material here.