Root Canal Anatomy Visualization using Three-Dimensional Computed- Tomography and Transparent Preparation

Three-dimensional Computed Tomography (CT) is used to analyze the topography of the root canal anatomy in order to make a decision in choosing root canal preparation method. There is a method that make extracted teeth transparent maintaining its anatomical shape and size. It is important to compare the accuracy of the two visualization methods. Objective: To compare the transmission accuracy of root canals anatomy by two visualization methods, three-dimensional CT and transparent tooth preparation. Methods: Mandibular third molar was used as sample. The three-dimensional CT scan was performed before extracting the teeth. Then teeth were extracted and placed in solutions that made them transparent. Results: Despite the fact that the character of dental origin in terms of the angle of the crown, the curvature of the crown, the deviation of the root showed in three-dimensional CT, other tooth anatomical parameters were equally well detected using a transparent tooth preparation. Overall, the curvature of the root canals is more clearly shown by transparent tooth preparation. Conclusion: Transparent tooth preparation provides superior visualization of real root canal anatomy compared to three-dimensional CT, however the later could give us more information about the relation of the tooth within the jaw.DOI: 10.14693/jdi.v20i2.15

Additive manufacturing of Ti-48Al-2Cr-2Nb alloy using gas atomized and mechanically alloyed plasma spheroidized powders

In this paper, laser powder-bed fusion (L-PBF) additive manufacturing (AM) with a high-temperature inductive platform preheating was used to fabricate intermetallic TiAl-alloy samples. The gas atomized (GA) and mechanically alloyed plasma spheroidized (MAPS) powders of the Ti-48Al-2Cr-2Nb (at. %) alloy were used as the feedstock material. The effects of L-PBF process parameters-platform preheating temperature-on the relative density, microstructure, phase composition, andmechanicalproperties ofprintedmaterialwere evaluated. Crack-free intermetallic samples with a high relative density of 99.9% were fabricated using 900 °C preheating temperature. Scanning electron microscopy and X-Ray diffraction analyses revealed a very fine microstructure consisting of lamellar α2/γ colonies, equiaxed γ grains, and retained β phase. Compressive tests showed superior properties of AM material as compared to the conventional TiAl-alloy. However, increased oxygen content was detected inMAPS powder compared to GA powder (~1.1 wt. % and ~0.1 wt. %, respectively), which resulted in lower compressive strength and strain, but higher microhardness compared to the samples produced from GA powder.(OLD) MSE-

Fibrin Glue Implants Seeded with Dental Pulp and Periodontal Ligament Stem Cells for the Repair of Periodontal Bone Defects: A Preclinical Study

A technology to create a cell-seeded fibrin-based implant matching the size and shape of bone defect is required to create an anatomical implant. The aim of the study was to develop a technology of cell-seeded fibrin gel implant creation that has the same shape and size as the bone defect at the site of implantation. Using computed tomography (CT) images, molds representing bone defects were created by 3D printing. The form was filled with fibrin glue and human dental pulp stem cells (DPSC). The viability, set of surface markers and osteogenic differentiation of DPSC grown in fibrin gel along with the clot retraction time were evaluated. In mice, an alveolar bone defect was created. The defect was filled with fibrin gel seeded with mouse DPSC. After 28 days, the bone repair was analyzed with cone beam CT and by histological examination. The proliferation rate, set of surface antigens and osteogenic potential of cells grown inside the scaffold and in 2D conditions did not differ. In mice, both cell-free and mouse DPSC-seeded implants increased the bone tissue volume and vascularization. In mice with cell-seeded gel implants, the bone remodeling process was more prominent than in animals with a cell-free implant. The technology of 3D-printed forms for molding implants can be used to prepare implants using components that are not suitable for 3D printing