Ultra-Etch is a 35% phosphoric acid solution. It features ideal viscosity, which, along with the use of the Blue Micro or Inspiral Brush tip, facilitates precision placement and superior control. Ultra-Etch is self-limiting in its depth of etch (average depth of 1.9μm with 20-second etch), creating an etch pattern that adhesives can penetrate for increased bond strength and reduced sensitivity. Studies demonstrate that Ultra-Etch’s unique self-limiting chemistry creates an optimal surface to receive resin. Though Ultra-Etch is viscous, it can penetrate into the smallest fissures or occlusal surfaces due to physical and chemical properties that promote capillary action. Its ideal viscosity maintains a layer thick enough to prevent premature drying.