Nanos and dental care

Nanos and dental care

By AVICENN Team – Last Added July 2022

What nanomaterials can be found in dental products?

In the field of dentistry as in the others, it is difficult today to distinguish the “promises” still in the state of research & development from the nano applications actually marketed. Nanoparticles have been used in dental composites for decades.

In France, the 2017 R-Nano report counts three “entities” (companies) having declared nano for “manufacture of instruments and supplies for medical and dental use”.
It makes it possible to identify several substances declared in nanoparticle form as used in the manufacture of "dental products" (or "for dental use"): aluminum oxide, iron oxide, silica (without however providing further details on the manufacturers or the type of products, the properties or the quantity of nano-registered substances).

According to Mr. Gardon-Mollard, Doctor of Dental Surgery, in dental offices, we would find nanoparticles¹Who's Afraid of Toxic Dental Materials?, The Dentalist, October 2019:

• about sealing cements (zinc oxyphosphates, CVIMAR…)
• about calcium silicates (Biodentin)
• about impression materials (elastomers)
• about composites and adhesives, dispersed mainly during polishing operations if these are carried out without spray or suction.
  
  

What do we know about the associated risks?

Exposure pathways and risks

Few “general public” resources on risks specifically related to nanoparticles in dental products are available online.

According to the professionals, the nanoparticles are confined in a resin which, once hardened, prevents the nanoparticles from detaching. Only a very small number of nanoparticles would be likely to be ingested, following wear or abrasion of the products – but in much lower proportions than those fromfood to toothpaste, lipsticks and balms, etc.

But what is true for consumers is less true for professionals: as the European Agency for Safety and Health at Work points out, " the milling, drilling, grinding and polishing of applied medical materials containing nanomaterials during dental and surgical procedures represent possible exposure situations. This is the case, for example, with the treatment of caries in dental care, for which fillings containing nanomaterials (e.g. nanoceramic fillings) are usually placed, which are adjusted to the anatomical shape by grinding the surface with the help of high-speed tools. During this procedure, there is a risk that nanoparticles will disperse into the air and be inhaled by the patient and the medical staff.”²Nanomaterials in the healthcare sector: occupational risks and their prevention, EU OSHA, E-facts 73, 2013.

These situations of exposure to nanomaterials exist throughout the life cycle of the material. The prosthetist, during the development of the material, can be exposed to it by inhalation. In the case of polishing or depositing a material, it is the patient and the practitioner who may be exposed to it, by inhalation – and to a lesser extent by swallowing for the patient.³See intervention by Prof. Élisabeth Dursun, “ Dental nanoparticles and biomaterials " when 21st public health day, organized by the ASPBD on November 4, 2021, 0:45′.

However, it is still too rare to see real benefit/risk approaches and prevention seems very weak to date.

What precautionary measures?

Some precautionary operating measures can be adopted during milling, polishing, etc. operations. to limit, ultimately, exposure to nanomaterials. Elisabeth Dursun quotes some of them in her November 2021 speech⁴See intervention by Prof. Élisabeth Dursun, “ Dental nanoparticles and biomaterials organized by the ASPBD on November 4, 2021 during the 21st public health day, based on recommendations from the Francophone Society of Dental Biomaterials (SFBD):

• sculpt the restoration in detail before setting, to reduce the amount of milled material for finishing and polishing
• use water to cool and vacuum more effectively during polishing
• ventilate the premises frequently
• protect staff:
  • wear an FFP3 mask when polishing, as well as glasses
  • ask assistants to step away when polishing
• prefer powder/liquid capsule systems
• use rubber dam for finishing when occlusion is not in play
• pay particular attention to vulnerable patients (asthma, chronic bronchial obstruction, etc.)