Are Silver Mercury Fillings Bad?

You’ve seen them! Perhaps still have them! Those ugly, black, silver-amalgam mercury tooth fillings on back teeth. If you still have them, consider the following:

Unlike safer composite fillings, silver-mercury (“amalgam”) fillings do not strengthen a tooth. In order for them to stay in the tooth, undercuts are made deep into the tooth structure so it can lock in place.  These undercuts can seriously weaken the tooth.

Additionally, “amalgam” fillings can slowly expand over time placing added pressure inside the tooth against the walls of the filling. This phenomenon is called “creep and flow” – like the filling is getting bigger over time.

Perhaps more significantly is the expansion/contraction the metal filling experiences with hot/cold cycling with foods and beverages. This ‘pumping’ expansion pressure adds more structural stress to the surrounding tooth, causing it to fatigue-fracture and crack … and break. Ouch!

As with any structural object, the net effect of these pressures and expansion/contraction is that over time the stress in the tooth must be relieved – and it does so by cracking and breaking; the tooth eventually fractures. Furthermore, cracks in the enamel surface provide tooth decay a quick path to deeper decay.

To make matters worse, silver-mercury fillings corrode or rust over time. Because they are not bonded to the tooth, saliva will leak around and under the filling – creating a new problem under the filling … more tooth decay!

Newer white tooth-colored filling materials have superior bonding qualities and therefore do not require a cavity with an undercut. They actually help strengthen the tooth. They also don’t expand like silver mercury fillings do, so they are safer for the tooth structurally. And, since they don’t have the heavy metal mercury in them, gone is the worry about whether there is any adverse health problems associated with these fillings.

Given the advances in dentistry and the uses of composite resin and porcelain, there is no reason to use mercury alloy fillings. Period! (Besides, they’re ugly!)

Teeth with silver-mercury fillings that have fractured, represent the number one reason dentists do so many crowns – to repair broken teeth that have silver fillings. Bottom line – if not repaired and strengthened, teeth crack, decay, become infected or even worse – the entire tooth will be lost. And that can get downright expensive!