In some cases the Windchill DTI wants to save Office Templates each time you close an Office document.
As shown in PTC Call C14677802, the DTI has no effect on the templates even when saved.
But there should be a way to stop this behavior from the side of the PDM/DTI.
Windchill 11.1 M020-CPS05
PTC Windchill Desktop Integration 11.1 M020-CPS05