Composite (or white fillings) match the color of your natural teeth and actually bond to your teeth, creating restorations that are nearly undetectable and make the restored tooth stronger than it was before. Composite fillings can also be made much smaller than an amalgam filling, so less natural tooth structure is lost.

When cost is an issue, and a large portion of a tooth is damaged or decayed, amalgam may be a patient's first choice. However, the mercury in amalgam fillings expands and contracts with heat and cold (think of the mercury in a thermometer). This will eventually cause the filling to fracture your tooth, and a crown will be required. Frequently these fractures also require root canal therapy or even loss of the tooth. For these reasons, an amalgam filling may not be the most cost effective or most sensible over time. Therefore, when decay or damage to a tooth is large an inlay or onlay will often be recommended rather than a filling.