A Hittite Seal and Seal Impressions from Tatarl? Höyük

Apical seal versus coronal seal

the results of the initial study. It was concluded that the apical fluids, with their primary source being blood serum, diffuse into the empty canal spaces, stagnate, undergo degradation and then act as a physicochemical irritant when they diffuse back into periapical tissues. In support of this theory of stagnation, in 1955 Dow and Ingle showed that the majority of the endodontic failures were...

Sharks shape the geometry of a selfish seal herd: experimental evidence from seal decoys.

Many animals respond to predation risk by forming groups. Evolutionary explanations for group formation in previously ungrouped, but loosely associated prey have typically evoked the selfish herd hypothesis. However, despite over 600 studies across a diverse array of taxa, the critical assumptions of this hypothesis have remained collectively untested, owing to several confounding problems in r...

Pierre Machtou presents a review of the clinically relevant literature on apical seal versus coronal seal Apical seal versus coronal seal CPD

19 The biological basis of endodontics is well established and underlines the dominant role of bacteria in the initiation, development and persistence of periapical disease (Kakehashi S et al, 1965) or apical periodontitis (AP) according to the terminology currently in use. The aim of clinical procedures is to prevent or eliminate bacterial infection from the root canal system (Orstavik D, Pitt...

Elastic leak of a seal

An elastomeric seal may leak by elastic deformation without any material damage. We describe elastic leak using a theoretical model, and watch a seal deform and leak using a transparent experimental setup. The elastomer seals the fluid by forming contact with surroundinghardmaterials. As the fluid pressure increases, the contact stress also increases but not as much. When the fluid pressure sur...

A Seal Generalizes Call Classes