6 research outputs found
Assessment of the botanical origin of Bulgarian honey samples using melissopalynological, DNA barcoding and NMR analyses
Polyfloral honey samples from Bulgaria were subject to parallel analyses of their
botanical origin and composition using traditional melissopalynology, DNAbarcoding based on the plastid rbcL gene and NMR analysis. The obtained
datasets were compared with each other to evaluate the information capacity of
the applied experimental methods. The results from the melissopalynological
and DNA-barcoding studies demonstrated a significantly higher resolution of the
latter, revealing the presence of pollen from a total of 17 plant families, 21 plant
genera and 5 plant species in comparison to pollen from only 7 plant families,
3 plant genera and 4 plant species identified by melissopalynology. The higher
resolution of DNA barcoding allows a more detailed characterisation of the
diet and foraging preferences of honey bees, including foraging on plant species
growing in lower abundance in the area. The comparison of the quantitative data
on floral honey composition for several plant genera and species reveals significant
differences between the relative abundance of the pollen grains estimated by
melissopalynological analysis and the relative abundance of rbcL clones in rbcL
libraries determined after DNA barcoding. All three applied methods confirm the
polyfloral botanical origin of the analysed samples and support routine NMR use
for the assessment of the floral origin of honey
NOVEL METHODS FOR THE ASSESSMENT OF CRACK PROPAGATION IN ENDODONTICALLY TREATED TEETH
Background: Vertical root fractures (VRF) can be defined as either complete or incomplete fractures that occur predominantly in endodontically treated teeth (ETT). The clinical symptoms and conventional radiographic techniques are not always accurate, which can lead to diagnostic errors. This motivated us to seek new, better techniques that can improve the prognosis and treatment of ETT with vertical fractures.
Objective: The aim of this study was to investigate the potential of three novel techniques: Cone Beam Computed Tomography (CBCT), Optical Computed Tomography (OCT) and 3D Profilometry for the visualization and assessment of VRF.
Methods: The study involved intact human premolars, extracted for orthodontic or periodontal reasons. The teeth were then endodontically treated and restored with prefabricated metal posts. No additional preparation of the coronal hard dental tissues was performed, apart from the access cavity. After thermocycling, their fracture resistance was evaluated in a standard testing machine. The resulted vertical fractures and crack propagation were evaluated using CBCT, OCT and 3D Profilometry.
Results: The CBCT provided visualization of the tooth in three planes: axial, coronal and sagittal. Root fractures were observed at the coronal and middle 1/3 of the root. The OCT provided highly-detailed, biomicroscopic cross-sectional images of the mesial and distal root surfaces. The images, obtained with 3D Profilometry showed the surface topography and provided precise information about the width and depth of the VRF.
Conclusion: All of the techniques used in this study proved to be highly informative, non-invasive and non-contact methods, suitable for the evaluation of VRF