A substance recently banned from gel nail polishes across the European Union is reportedly still in use in certain dental procedures in Portugal — raising concerns that regulatory action could expand to medical-device materials, Euro News reported Friday.
The chemical, Trimethylbenzoyl Diphenylphosphine Oxide (TPO), acts as a photoinitiator, triggering polymerization (hardening) of gels and resins when exposed to UV light. The European Commission has classified TPO as “carcinogenic, mutagenic and toxic for reproduction,” and a ban on its use in cosmetics entered into force on Sept. 1.
The ban has unsettled nail-care professionals, who now face the challenge of disposing of existing stock and reformulating products without TPO. But the compound also finds uses in other sectors, including dentistry, 3D printing, prosthetics, and various resin-based materials.
According to a Rádio Renascença report on Friday, Portugal’s Dental Association (Ordem dos Médicos Dentistas, OMD) has confirmed that TPO is used in treatments such as fissure sealing, tooth restoration and even whitening. The OMD maintains that the amounts used in dental applications are minimal relative to those in varnishes, though it did not cite exact concentrations.
Portugal’s regulatory agency Infarmed told Renascença it was unaware of TPO’s presence in dental materials but emphasized that it is enforcing the EU ban on cosmetics containing the chemical. Dentistry and dental supply companies are now concerned the prohibition could be extended to medical devices and resinous materials.