Fillers are exogenous substances of biological or synthetic origin. These can be injected into the dermis or subcutis or into deeper planes in order to correct skin blemishes caused by skin aging such as wrinkles or depressions or to give greater volume and fullness to areas of the face that are lacking.
The characteristics of the fillers are the biocompatibility, their compatibility with the human body, necessary to avoid local or general reactive phenomena, the ability to model on the anatomical structures giving plasticity to the skin with the ability to remain for a certain amount of time (8 to 24 months) in the receiving site.
In relation to the chemical composition and the duration of the result, the fillers subdivide the three sub-categories: reabsorbable fillers, semi-permanent fillers, permanent fillers.
Hyaluronic acid in gel form is the most widely used injectable in the correction of wrinkles and signs of expression and volumes of the face. Hyaluronic acid is the most widely used due to its unexceptionable safety in use as it can be dissolved thanks to hyaluronidase, an enzyme. Hyaluronic acid is a natural substance, normally present in human tissues as an integral part of the dermal matrix, and as such does not require any allergological tests. The recent research also seems to demonstrate that the same can act as a modulator of muscle movement conditioning and also modifying the negative emotions of the face.