Fabrication of a porous hydroxyapatite scaffold with enhanced human osteoblast-like cell response via digital light processing system and biomimetic mineralization

Abstract Hydroxyapatite is a commonly used scaffold material for bone tissue engineering. However, the osteogenic mechanism of hydroxyapatite scaffolds remains unclear. Recently, we have prepared a hydroxyapatite scaffolds with microchannels and porous structures (HAG) which have good osteogenic effects in vitro and in vivo. In present study, we explained the mechanism of HAG scaffolds promoted the osteogenic differentiation from the perspective of miRNA differential expression. We used microarray assays to analyze the expression profiles of miRNAs from the osteogenic differentiation of hPMSCs with or without HAG; 16 miRNAs were upregulated and 29 miRNAs were downregulated between the two types of cells. And overexpression the differential miRNAs could promote the osteogenic differentiation of hPMSCs. Additionally, gene ontology analysis, pathway analysis, and miRNA-mRNA-network built were performed to reveal that the differentially expressed miRNAs participate in multiple biological processes, including cell metabolic, cell junction, cell development, differentiation, and signal transduction, among others. Furthermore, we found that these differentially expressed miRNAs connect osteogenic differentiation to processes such as axon guidance, MAPK, and TGF-beta signaling pathway. This is the first study to identify and characterize differentiational miRNAs derived from HAG-hPMSC cells.

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Bracket transfer accuracy with two different three-dimensional printed transfer trays vs silicone transfer trays

The Angle Orthodontist ◽

10.2319/040821-283.1 ◽

2022 ◽

Author(s):

Lea Hoffmann ◽

Hisham Sabbagh ◽

Andera Wichelhaus ◽

Andreas Kessler

Keyword(s):

Three Dimensional ◽

Processing System ◽

Similar Distribution ◽

Digital Light Processing ◽

Directional Bias ◽

Indirect Bonding ◽

Significant Difference ◽

Transfer Tray ◽

Transfer Accuracy ◽

Bracket Positioning

ABSTRACT Objectives To compare the transfer accuracy of two different three-dimensional printed trays (Dreve FotoDent ITB [Dreve Dentamid, Unna, Germany] and NextDent Ortho ITB [NextDent, Soesterberg, the Netherlands]) to polyvinyl siloxane (PVS) trays for indirect bonding. Materials and Methods A total of 10 dental models were constructed for each investigated material. Virtual bracket placement was performed on a scanned dental model using OnyxCeph (OnyxCeph 3D Lab, Chemnitz, Germany). Three-dimensional printed transfer trays using a digital light processing system three-dimensional printer and silicone transfer trays were produced. Bracket positions were scanned after the indirect bonding procedure. Linear and angular transfer errors were measured. Significant differences between mean transfer errors and frequency of clinically acceptable errors (<0.25 mm/1°) were analyzed using the Kruskal–Wallis and χ2 tests, respectively. Results All trays showed comparable accuracy of bracket placement. NextDent exhibited a significantly higher frequency of rotational error within the limit of 1° (P = .01) compared with the PVS tray. Although PVS showed significant differences between the tooth groups in all linear dimensions, Dreve exhibited a significant difference in the buccolingual direction only. All groups showed a similar distribution of directional bias. Conclusions Three-dimensional printed trays achieved comparable results with the PVS trays in terms of bracket positioning accuracy. NextDent appears to be inferior compared with PVS regarding the frequency of clinically acceptable errors, whereas Dreve was found to be equal. The influence of tooth groups on the accuracy of bracket positioning may be reduced by using an appropriate three-dimensional printed transfer tray (Dreve).

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Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria

Brazilian Dental Journal ◽

10.1590/0103-6440201601028 ◽

2016 ◽

Vol 27 (6) ◽

pp. 717-726 ◽

Cited By ~ 8

Author(s):

Alinne Azevedo Pereira da Silva Suruagy ◽

Adriana Terezinha Neves Novellino Alves ◽

Suelen Cristina Sartoretto ◽

José de Albuquerque Calasans-Maia ◽

José Mauro Granjeiro ◽

...

Keyword(s):

Bone Repair ◽

Chemical Properties ◽

Wilcoxon Test ◽

In Vivo Studies ◽

Control Group ◽

Porous Hydroxyapatite ◽

Physico Chemical ◽

Hydroxyapatite Scaffold ◽

Xrd Patterns

Abstract The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

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