Dentists will no longer use them on children or pregnant or breastfeeding women
The use of silver coloured fillings is to be phased down by Irish dentists from July 1st.
The dental amalgam fillings, as they are called, contain several metals including mercury.
Dentists will no longer use them on the teeth of children under 15 or pregnant or breastfeeding women - unless deemed strictly necessary on medical grounds.
The President of the Irish Dental Association (IDA), Dr Kieran O'Connor, said the new regulations are being brought in with the aim of reducing the amount of mercury in the environment.
"Five years ago, Ireland was a signatory to the Minamata Convention and the new EU regulations governing dental amalgam stems from the phased implementation of that United Nations agreement.
"The convention brought about a global agreement to reduce environmental contamination caused by mercury.
"It includes a ban on new mercury mines, the phase-out of existing ones and the phase down of mercury use in a number of products and processes."
The IDA said placing or removing amalgam fillings can cause mercury waste to be released into the environment.
Dr Eamon Croke, who helped to produce the IDA's patient information leaflet on this issue, said the fillings are safe, strong and long lasting.
"Dental amalgam has been in use for over 150 years and its safety and reliability has been well researched.
"In certain circumstances a dental amalgam filling may be the best option to achieve a safe and satisfactory outcome and if that is the case the dentist will explain why.
"However, if a patient doesn't agree they should say it to their dentist so alternative arrangements can be put in place."
Dentists are also not permitted to give medical card patients white fillings for their back teeth.
"Many people who have amalgam fillings may be wondering about their safety.
"Many will have had these fillings for a long time and they will be working very well.
"Their removal is to be avoided because it usually leads to the creation of a larger cavity."