Tissue management with dental impression materials.

The coordination of perceptive tissue management, diligent tooth preparation and prudent selection of the impression material for specific clinical conditions ensures the success of cast and ceramic restorations. The introduction of a knitted cord (Ultrapak with Astringedent) has alleviated the arduous aspects of tissue displacement and the new impression materials have displayed exceptional accuracy but healthy tissue is fundamental.

Mouse-killing in the rat: effects of sensory deficits on attack behaviour and stereotyped biting.

Sensory transections were performed in rats that killed mice after food-deprivation and subsequent satiation. Following partial maxillary or combined maxillary and optic deafferentation, but not after optic lesions alone, the number of mouse-kills declined sharply. This decline was accounted for by approximately a 50 per cent decrease in the number of mouse-presentations in which attack-behaviour took place and in the occurrence of attack-behaviour that did not always lead to a kill because rats frequently failed to bite. Furthermore, examination of killed mice revealed a shift in the distribution of body-bites away from the rostral regions normally seized by rats to more caudal areas of the mouse's body. Results indicate that certain stimulus-characteristics of mice mediated by the maxillary and optic nerves are important determinants of attack-behaviour and stereotyped biting in the rat.