iBOND Etch 35 Fluid, 1 x 15 mL - 66039868iBOND Etch 35 Gel, 2 x 2.5 mL Syringe - 66039862 iBond Etch etchants are available in two forms to provide dentists with a choice. iBond Etch 35 Gel and iBond Etch 35 Fluid use the traditional strength of 35% phosphoric acid.