direct restoration of severely damaged endodontically treated teeth (ett) using available and conventional and current matrix systems is sometimes impractical and in some clinical cases is impossible. the aim of this paper is to introduce and describe a new matrix system based on rigid tray technique (rtt) for dealing with such difficult clinical cases.

In the last decade an increasing number of farmers worldwide have adopted the technique of ammoniation as a means of increasing the utilisation of roughages by ruminants, Our work has identified problems with ammoniation which are similar to those encountered with ammoniated molasses in the 1950%. Since July 1984 there have been several outbreaks of hyperexcitability in cattle fed ammoniated ro...