De or het rimpelbehandeling?

The correct Dutch article is:

de rimpelbehandeling

Rule Words ending in -ing: almost always de. See the rule

How to use rimpelbehandeling

the rimpelbehandelingde rimpelbehandeling
this rimpelbehandelingdeze rimpelbehandeling
that rimpelbehandelingdie rimpelbehandeling
our rimpelbehandelingonze rimpelbehandeling
your rimpelbehandelingjouw rimpelbehandeling
every rimpelbehandelingelke rimpelbehandeling
which rimpelbehandeling?welke rimpelbehandeling?
a big rimpelbehandeling / the big rimpelbehandelingeen grote rimpelbehandeling, de grote rimpelbehandeling