3D-Sides lost after slicerprogram ?

Designed a 3D part in Designspark.

Used the design in Xyz slicer and saved the settings.

Now i want to use the part again in designspark but i notice it got all the triangles from my slicerprogram.

Is it possible to get the correct sides again, instead of all those triangle-slicer, sides ?

Thanks in advance,

Peter