All the documentation and examples I\'m finding online for setting Z-Index to bring an element forward in Silverlight are using a Canvas element as a container.
My i
set zIndex of your element in this way
var zIndex =
((Panel) element.Parent)
.Children.Cast<UIElement>()
.Max(child => Canvas.GetZIndex(child))
;
zIndex++;
Canvas.SetZIndex(element, zIndex);