White Fillings 
Many patients opt to replace their silver amalgam fillings with white fillings. The reasons often include the following: aesthetics, child patient, a known history of allergy to mercury, a history of impaired renal function or a preference to have non-mercury containing fillings in their mouth.

White fillings exist as an alternative to silver amalgam fillings and have the distinct advantages of superior aesthetics, and lack mercury content. They can last up to 10 years depending on the diet and wear characteristic of the individual patient.

Silver Fillings 
Prior to white fillings, amalgam was the defacto standard as a tooth restorative material. As a basic restorative material, it continues to be the most durable and the most economical. In general, it also possesses a far higher wear resistance than white fillings and therefore may still be the treatment option of choice in the back of the mouth where strength and durability are often a factor.

However, mercury fillings (amalgam), have the significant disadvantage of generating toxic mercury vapour during chewing. Although this vapour falls well below the daily toxic dose of mercury for the average individual, it can nonetheless impair kidney function in susceptible individuals, deposit in the brain, liver and kidneys and in rare cases create a true allergic response.