Scientific Twitter: The flow of paleontological communication across a topic network.

The field of paleontology, which is based principally on observations of the natural world, includes an active community that is engaged across multiple social media platforms, consisting of museums, academic researchers, amateur fossil collectors, paleontological artists, and commercial fossil dealers. As such, it represents an ideal environment for examining the people, interactions, and flow of scientific information. Using interactions involving the four most popular Twitter hashtags for paleontology, this embedded mixed methods study defined the members of this social world and investigated how they influenced and controlled the flow of information, as well as how their expression of scientific practice was related to their identity.

Effect of dentinal bonded resin post-core preparations on resistance to vertical root fracture.

An in vitro study was conducted to compare the resistance to failure of two restorative protocols for endodontically treated teeth. Half of 24 specimens received cemented cast post-core restorations and the other half were restored with dentin-bonded composite resin using the ferric oxalate, NTG-GMA, and the PMDM system developed by Bowen. The dentin-bonded resin post-core restorations provided significantly less resistance to failure than the cemented custom cast post-core.