The last 15 – 20 years have brought to light many concerns about the safety of the materials used in modern dental fillings.

In recent years, dental offices around the world have been bombarded with patients who’re eager to rid themselves of “dangerous” silver amalgam fillings, in favor of the much “safer” tooth-colored composite fillings that are thought to pose no health risks. Not to mention composites look more natural.

Before you rush out to replace your old fillings, or your dentist tells you that you have a new cavity and you need to decide what kind of material the tooth is to be filled with, it’s important to learn just what these materials are made of, and their potential impact on your health.

Temporaries (Zinc Oxide)

Temporary fillings are typically made of a combination of zinc oxide and eugenol, combined with various accelerators and excipients used to harden the soupy mixture and help it to adhere to the area inside the tooth. Dentists use temporaries after a root canal surgery, or in cases where they’ve filled a particularly deep or wide-spread cavity. This is done so the dentist can go back in at a later time and ensure infection doesn’t set in before putting a permanent filling in place.

Once cured, this type of filling is quite safe and isn’t known for emitting toxic chemicals that are harmful to people’s health. They’re very fragile and tend to only last about 3 weeks before all the material breaks off and/or dissolves.

Cast Gold

Gold fillings have fallen out of popularity over the years, due to their high cost (approximately 10x that of silver amalgam) and their aesthetically unpleasant appearance in contrast to our white teeth. This material bonds to the area inside the cavity better than amalgam, and less healthy portions of a tooth have to be removed to make it fit (amalgam fillings often require drilling 65 – 80% of the tooth being filled in order to bond the material to the tooth properly.)

Gold is actually the safest of all permanent fillings; it doesn’t emit any dangerous chemicals whatsoever. This material lasts 20 years or more.

Silver Amalgam

Most of you have likely heard about the dangers surrounding silver amalgam fillings (learn more), which contain small amounts of mercury known to leach from the filling itself in small amounts each day. Amalgam requires significant amounts of healthy parts of a tooth to be removed in order to create pockets (called retentive features) which hold the filling, since it’s not glue or bonded to the tooth like composite fillings.

Most of the taboo surrounding amalgam originally arose due to complaints from patients who became ill while having their amalgam fillings replaced with white composite fillings. Other than rare hypersensitive reactions during, and immediately following removal of amalgam fillings at the dentists office, there is no clinical evidence to support the claims that silver amalgam and the mercury in them poses a significant risk to our health. Amalgam can last just as long as gold. Don’t replace silver for the sole purpose of ridding yourself of “mercury poisoning.” (source)

Polymer Composite Resin (Tooth Colored)

Polymer composite resin fillings are the most common type of filling nowadays, since they are tooth-colored, and thought to be much healthier than mercury-containing amalgams. These fillings are made up of various resins, polymers, and ceramic compounds. As of late, composites have shown to be very disruptive to human health. They’re bonded to the tooth, and thus only the damaged area needs to be drilled out to repair dental cavities.

New studies are bringing the dangers of composite fillings and their Bisphenol A (BPA) content. BPA’s are extremely dangerous to both short and long-term health (source). One recent study showed that up to 16% of children with composite fillings had behavioral problems (source).

Conclusion

Recent literature seems to indicate that we may have jumped the gun with regards to the health dangers posed by silver amalgam used in dentistry. While they do leach small amounts of mercury, the dangers of BPA’s found in composite fillings are much more far reaching, due to their effects on human hormone balance (learn more).

All in all, gold fillings are indeed the safest filling material available. Prepare to pay more if you go that route. Few dental insurance plans will cover gold fillings.