Table 1.

Characteristics of the nine HA fillers used.

Samples	Description
Filler 1	Stabilized hyaluronic acid 20 mg/ml, nonanimal origin, pH 6–7.5 biphasic
Filler 2	Cross-linked hyaluronic acid 20 mg/ml with lidocaine hydrochloride 3 mg/ml, biphasic
Filler 3	Hyaluronic biorevitalizing gel, medium-chain hyaluronic acid 20 mg/ml in a physiologic buffer, produced from Streptococcus equi bacteria
Filler 4	Hyaluronic acid 20 mg/ml-sodium chloride 16 mg/ml, from bacterial biofermentation, BDDE cross-linking agent, monophasic
Filler 5	Reticulated hyaluronic acid 25 mg/ml with lidocaine hydrochloride 3 mg/ml, animal origin, pH 7.2
Filler 6	Reticulated hyaluronic acid 24 mg/ml in physiological buffered saline, from biotechnological fermentation, low BDDE content, monophasic
Filler 7	Auto cross-linked hyaluronic acid–sodium chloride 18 mg/ml
Filler 8	Hyaluronic acid 2 mg and cross-linked HA 20 mg-sodium chloride 6.9 mg, nonanimal origin, endotoxin- and BDDE-free
Filler 9	Cross-linked hyaluronic acid 20 mg/ml-lidocaine hydrochloride 3 mg/ml pH 7, biphasic