The irregular and variable structure of the apical region of human teeth represent special challenges during endodontic therapy. Obturation techniques based on the penetration of adhesives into dentinal tubules are unlikely to be successful and adhesive techniques must depend on impregnation of a hybrid layer.

A new occurrence of fossil butternut is recognized based on a permineralized highly scabrate walnut from the middle Miocene of western Washington, USA. The specimen fits the circumscription of Juglans bergomensis (Balsalmo Crivelli) Massalongo, a species that was widespread in Europe and Asia during the Neogene. The occurrence near Brady, Washington, supplements the previously recognized occurrence from Banks Island, Canada, indicating a distribution in mid-latitude western North America as well as Europe and Asia during the Miocene.