Concentrated growth factor (CGF) is a newly generated complex that comprises a fibrin matrix incorporating growth factors and plasmatic and leukocyte cytokines. It has been widely used in bone regenerative medicine. However, the effect of CGF on peripheral nerve regeneration had not been previously investigated. The aim of the present study was to evaluate the possibility of using CGF for nerve regeneration by i) investigating the effect of CGF on the proliferation of Schwann cells (SCs) and secretion of neurotrophic factors nerve growth factor (NGF) and glial cell line‑derived neurotrophic factor (GDNF) in vitro; and ii) analyzing the effect of CGF on functional nerve recovery after nerve injury in vivo. CGF was prepared from venous blood taken from rats, and using scanning electron microscopy (SEM) we noted that it featured a fiber‑like appearance with pore size ranging from 0.1 to 1.0 µm. The soluble component of CGF was used to produce conditioned media with which to treat the Schwann cell line. A cell counting kit-8 assay and cell cycle analysis were both used to study the proliferative effect of CGF on SCs. Reverse transcription-quantitative PCR and western blot analysis demonstrated that there was an increase in the mRNA and protein expression of NGF and GDNF, both of which are markers of SC neurotrophic secretion. A model of sciatic nerve crush injury was established for the in vivo experiment, and CGF was found to increase the sciatic functional index (indicative of nerve function). We noted that CGF increased SC proliferation and secretion of neurotrophic factors in vitro, and promoted functional recovery after peripheral nerve injuries in vivo. These results suggest that CGF is a promising candidate biomaterial for peripheral nerve regeneration, and may potentially be utilized to repair nerve injuries.

Objectives:The aim of the current study was to evaluate the application of two advanced noise-reduction algorithms for dental micro-CT images and to implement a comparative analysis of the performance of new and current denoising algorithms.Methods:Denoising was performed using gaussian and median filters as the current filtering approaches and the block-matching and three-dimensional (BM3D) method and total variation method as the proposed new filtering techniques. The performance of the denoising methods was evaluated quantitatively using contrast-to-noise ratio (CNR), edge preserving index (EPI) and blurring indexes, as well as qualitatively using the double-stimulus continuous quality scale procedure.Results:The BM3D method had the best performance with regard to preservation of fine textural features (CNREdge), non-blurring of the whole image (blurring index), the clinical visual score in images with very fine features and the overall visual score for all types of images. On the other hand, the total...

The aim of this study was to investigate the efficacy of various fluoride varnishes in the protection of the structural and nanomechanical properties of dental enamel. Demineralized enamel specimens were imaged using a high-resolution micro-CT system and lesion parameters including mineral density and lesion depth were extracted from mineral density profiles. Nanoindentation elastic modulus and hardness were calculated as a function of penetration depth from the load-displacement curves. The average depth of the lesion in specimens with no prior fluoride varnish treatment was 86±7.19 μm whereas the varnish treated specimens had an average depth of 67±7.03 μm (P<0.05). The mineral density of enamel lesions with no fluoride varnish treatment had an average of 1.85 gr/cm3 which was 25% lower than the corresponding value in varnish treated enamel and 37% lower than sound enamel. While, in the varnish treated group, elastic modulus and hardness values had decreased by 18% and 23%, respectively, the corresponding values in the non-varnish treated specimens had a reduction of 43% and 54% compared to the sound enamel. The findings from this study highlight the preventive role of fluoride varnishes. Addition of calcium and phosphate does not seem to enhance or inhibit the prevention or remineralization performance of fluoride varnishes.