The Dentex project aims at measuring the exposure to composite dust and bioaerosols in dental clinics as well as assessing the potential risks this exposure poses to dental workers’ health.

Preliminary results

During the initial part of the study, composite particles were generated in the lab by drilling in two different types of dental composites. The particles were subsequently characterized by microscopy to determine their size. This is important because a particle’s size directly influences how far into our respiratory system it may penetrate.
The characterization showed that generated composite particles had sizes in the range of nanoparticles and hence the potential to deposit deep into the airways.

The collected particles were further studied in assays containing human lung cells, and analyses showed that they were absorbed by the exposed cells. Furthermore, the highest exposure doses were toxic to cells. These results have been published in the journal Dental Materials.

Further research

Upcoming activities in the project comprise an air sampling campaign in public and private dental clinics as well as an in-depth characterization of the composite particles’ toxicological effects on the human lung. Stationary air quality samplers will be placed in the treatment rooms. Additionally, dental health care personnel will carry personal air samplers throughout their workday.

As dental personnel may be exposed to air borne microorganisms (bioaerosols) like viruses, bacteria, and fungi, the project will also assess the amounts and types of bioaerosols in dental clinics. Preliminary results indicate that the number of aerosol particles varies according to the procedure performed, and that some procedures create more aerosol than others. Currently, the sampling campaign is continued, and. the particles will subsequently be characterized in terms of size and type.

3D lung model

Cell culture experiments will be performed in a special chamber designed to mimic the inhalation of particles in the lung. A 3D-model will be used, which contains multiple types of lung cells and hence is more representative of a human lung than the model used in previous experiments. Using the 3D-model, signs of fibrosis (scar formation) will be assessed by analyzing biomarkers for inflammation as well as proteins specifically produced during scar formation.

At present, little is known about what harmful effects composite dust may have on organs other than the lung. Studies have however shown an association between living in highly polluted areas and the risk of some types of brain diseases. We therefore aim to study the effects of composite particles on cells in the human central nervous system, such as astrocytes and neurons. Furthermore, in vivo studies will confirm whether particles can be found inside brain tissue after inhalation.

Project organisation

Project Manager: Lina Wik

Project Group: Rubiyat Islam, Torunn Kringlen Ervik, Pål Graff, Anani Afanou, Shan Narui.

External collaborators: Dentex is a collaboration between Tannhelsetjenestens kompetansesenter øst (TkØ), The Nordic Institute of Odontological Materials (NIOM) and STAMI. Project partner at TkØ: Vibeke Ansteinsson; project partner at NIOM: Håkon Valen.