RESUMO
Objectives: Humans are unknowingly exposed to mycotoxins through the consumption of plant-derived foods and processed products contaminated with these toxic compounds. In addition to agricultural losses, Fusarium toxins pose a threat to human health. However, the effects of fusariotoxins on the viability and proliferation of stem cells have not been fully explored. We investigated the cytotoxic effects of deoxynivalenol (DON) and B-trichothecene mix (MIX) on mesenchymal stem cells (MSCs) and the L929 fibroblast cell line. Materials and Methods: MSCs were isolated from the dental pulp tissue. The doubling time and viability of dental pulp stem cells (DPSCs) and L929 cells were determined using the MTT assay. The following doses of B-trichothecenes (0.25-16 µg/mL; 24 hours and 48 hours) were used to evaluate cytotoxicity. In addition, changes in the confluency-dependent response of DPSCs to DON toxicity were determined. Moreover, we investigated the effect of DON on cell death via acridine orange/ethidium bromide (AO/EB) double staining. Results: A DON and MIX showed a dose- and time-dependent inhibitory effect on the proliferation of both cells. DPSCs exposed to DON for 48 hours (IC50 = 0.5 µg/mL) were found to be 16-fold more sensitive than L929 cells (IC50 = 8 µg/mL). Compared with a culture with 80% confluency, DPSCs from a 50% confluent culture were more sensitive to varying doses of DON (0.25-4 µg/mL, 24-48 hours). Moreover, AO/EB staining showed that treatment of DPSCs with DON led to a significant increase in cell death (17% for 2.4 µg/mL; 50% for 4.8 µg/mL). Conclusion: This study reveals that undifferentiated MSCs are significantly more sensitive to DON than differentiated somatic cells (L929). Given that humans are frequently exposed to these mycotoxins, our findings imply that prolonged exposure to them may also have harmful effects on cellular differentiation and embryonic development.
RESUMO
Use of direct composite and indirect laminate veneers has been an alternative to metal- and all-ceramic crowns for anterior teeth restorations. Dental traumas are the most common reasons for excessive tissue loss. Treatment options depend on the amount of remaining tissue, the extent of the damage to dental pulp and periapical tissues and the time elapsed before dental treatment. The aim of this case report was to evaluate the direct and indirect techniques used in the treatments of traumatically fractured anterior teeth. In Case 1, a 29-year-old male patient attended to the clinics of the Department of Restorative Dentistry, Faculty of Dentistry, Istanbul University for the replacement of old composite restorations. According to anamnesis, the anterior teeth had fractured because of falling from bicycle. Dentinal pins used to retain the composite restorations were screwed out and indirect composite laminate veneers were placed. In Case 2, a 27-year-old male patient attended to our clinic for the treatment of his anterior teeth which were fractured due to a fall. A different type of technique, a silicon guide, was used to mimic the natural teeth surfaces precisely. In Case 3, a 16-year-old female patient attended to our clinic for the treatment of her anterior teeth which were fractured in a car accident. On clinical evaluation, related teeth were found to be non-vital and application of fiber posts was considered suitable before direct composite restorations. In conclusion, all of these techniques may be used for traumatized anterior teeth. Esthetical necessities and functional forces should be taken into consideration in material choice.