Please explain the 6th-generation bonding agents to me.

6^th-generation bonding agents are self-etching, which means that they do not need phosphoric acid to demineralize tooth structure. They contain a self-etching primer that demineralizes and primes the tooth structure simultaneously. They also utilize a hydophobic adhesive that bonds more readily to composites. The difference between type I and type II self-etching adhesives is that with a type I product, the primer and adhesive are applied in two separate steps. The primer is applied first, followed by an air-thinning step to evaporate the solvent. Next, the adhesive is applied, air-thinned and in most cases, light-cured. With a type II product, the primer and adhesive are mixed together immediately before application and then applied in one step. OneCoat Self-Etching Bond (Coltene/Whaledent, Inc.) is an example of a 6^th-generation, type I product. It is sold either in single-unit doses or in 5-ml bottles each of primer and adhesive. Generally, type I bonding agents are less technique sensitive.