<prompt> The components of fourth generation dentin bonding systems are described asSelf etching adhesiveSelf etching primeradhesiveTotal etch, multi bottleTotal etch, single bottle  <response>: As in the fourth-generation adhesives, enamel and dentin are etched simultaneously; these systems were initially called the total-etch technique, now they are commonly known as the three-step etch-and-rinse technique.Ref : Talal A, Nasim HM, Khan AS. Enamel etching and dental adhesives. InAdvanced Dental Biomaterials 2019 Jan 1 pp. 229-253. Woodhead Publishing 