I have done 1 ml stylage filler before and I want something better. Is it OK to use a different type of filler?

Stylage is a hyaluronic acid based dermal filler and so it will generally be safe to add another filler from this genre. But it all depends on where the filler was placed and for what indication it was used for.

In my practice I have been using the Restylane range of dermal fillers for over 10 years with fantastic results, longevity and patient satisfaction. Recently I have introduced the Teosyal RHA range with pleasing results as well.

I only use hyaluronic acid based dermal fillers because they have the highest safety record and can be reversed in the events of medical compilations with a dissolving enzyme called hyaluronidase. 

Yes, it is possible to layer a different dermal filler on top of perlane. This is an advanced injection technique. Consult with an experienced and expert physician injector.