Break words in textbox (with TextWrapping=Wrap)
I don't think there is a direct property to achieve the result. TextTrimming property is available only for TextBlock. It is better to add linebreak to achieve the result.
Just try it with TextAlignment="Justify"
<TextBox TextAlignment="Justify" TextWrapping="Wrap" Height="250" MinWidth="250 " Width="250" Text="Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce ligula nulla, cursus finibus mauris vel, rhoncus blandit sem. Fusce fermentum sed sem a porttitor. Proin id convallis ex."/>