Background: To determine the toxicity of aqueous dilutions of a universal self-priming dental adhesive (DA) and
comparing these with those elicited by exposure to ionizing radiation (IR), Zoledronic acid (Z) treatment and the
synergic effects of the combined treatment with IR+Z.
Material and Methods: The genotoxic effect of DA was determined by the increase in the frequency of micronuclei
in cytokinesis-blocked in cultured human lymphocytes before and after exposure to 2Gy of X-rays. The cytotoxic effect was studied by using the MTT cell viability test in normal prostate cell lines (PNT2) after exposure
to different X-ray doses (0Gy-20Gy). The cell lines divided into different groups and treated with different test
substances: DA in presence of O
2
, DA in absence of O
2
, Z-treated and control.
Results: An in vitro dose-dependent and time-dependent cytotoxic effect of DA, Z and IR on PNT2 cells (
p
>0.001)
was demonstrated. DA without-O
2
, following the recommendations of manufacturers, had a more pronounced
effect of increasing cell death than DA with-O
2
(
p
<0.001). In the genotoxicity assay, DA at 25% of its original
concentration significantly increased chromosome damage (
p
<0.001). The samples studied were found to be toxic,
and the samples photo-polymerized in absence of O
2
showed a bigger cytotoxic effect comparable to the additive
toxic effect showed by the combined treatment of IR+Z.
Conclusions: Additional effort should be carried out to develop adhesives, which would reduce the release of hazardus substances; since toxic effects are similar to that reported by other agents whose clinical use is controlled by the
health authorities
