Dental Offices

Why am I being warned about potential exposure to chemicals in dental offices?

  • Some chemicals used in dental procedures are on the Proposition 65 list because they can cause birth defects or other reproductive harm.
  • Proposition 65 requires businesses to determine if they must provide a warning about exposures to listed chemicals.

Dental offices can expose you to chemicals on the Proposition 65 list during some procedures.  These include sedation with nitrous oxide; some root canals, crown placements or removals, dental bridge placements; tooth restorations with fillings that contain mercury; and the use of some dental appliances.

Icon representing dental offices


Examples of chemicals you may be exposed to in dental offices include:

  • Mercury.  A heavy liquid metal, mercury is used in some silver-colored dental amalgam fillings.
  • Nitrous Oxide.  Commonly known as “laughing gas,” nitrous oxide is used in combination with other gases to ease pain and anxiety during certain dental procedures.

How does exposure to these chemicals occur in dental offices?

  • Dental patients breathe in nitrous oxide and mercury vapors during dental procedures.  They can also swallow low levels of mercury vapor during the placement or removal of dental amalgam fillings.
  • During pregnancy, mercury can pass to the unborn baby when:
    • The mother has amalgam fillings put in or removed.
    • The mother has amalgam fillings and grinds her teeth.

During pregnancy, nitrous oxide can pass to the unborn baby when the mother undergoes a dental procedure using this gas.

How can I reduce my exposure to chemicals in dental offices?

  • If you have dental amalgam fillings that are in good condition, avoid having them removed.
  • If you need a tooth filling, talk to your dentist about using alternatives to dental amalgam that contains mercury.  This is especially important for pregnant women and children under the age of six.
  • When planning for dental work, talk to your dentist about anesthetic options other than nitrous oxide, especially if you are pregnant.

For more information:

General Fact Sheets and Resources

Proposition 65

  • California Environmental Protection Agency (CalEPA)
    Office of Environmental Health Hazard Assessment (OEHHA)
Posted March 2018

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