Dear Mrs. Moussa,
which product to use as a filler depends on the indication for which it should be used. A Liquid Lift or VolumeLift requires a filler with a higher concentration of hyaluronic acic, i.e. 30 - 36 mg/ml as opposed to a filler with 16 - 18 mg/ml, which is used in the dermal plane and not deeper.
As you can see, the decision should be made according to the indication for which the product sould be used - superficial or deep application.
There exist several studies on different products and their cross-linking technique.
Dr. E. Höfter,
Plastische Chirurgie an der Rotkreuzklinik