Final answer:
The area where resin of the adhesive system interlocks with dentinal collagen is called the hybrid layer, which is essential for bonding composites to the tooth.
Step-by-step explanation:
The name of the area in which the resin of the adhesive system micromechanically interlocks with dentinal collagen is known as the hybrid layer. This term is used specifically in dentistry to describe a layer formed by the intermingling of dental adhesive resins and the superficial layer of dentin where the collagen fibers are exposed after the etching process. The hybrid layer is crucial for the adhesion of composites to the tooth structure, creating a strong bond necessary for the durability of the restoration.