the present invention relates to a process for the preparation of a completely biocompatible and reab - sorbable hydrogel , through the use of alcoxides of polymers and / or resins containing hydroxyl functions . the invention also relates to the hydrogel obtainable with said method and uses thereof . in particular , the invention relates to the use of said hydrogel for the preparation of an injectable filler for correcting and / or treating different types of tissue deficits .