Just to keep the nomenclature straight ... There's lots of SSI(Small-Scale-integration) and MSI(Medium-Scale-integration) logic.

First, however, there's a difference between SSI and MSI.

SSI refers to buffers, gates and individual flipflops, etc.

MSI is, simply put, multiple SSI's combined as a single functional unit with common controls. For example, 7400, 74125, 74112, and 7474 are SSI's, but 74283, 74164, 74151, 74165, 74273, 7492, 74163, and 74652, among very many others, are MSI's.

These functions exist in various technologies, though, e.g. RTL, DTL, ECL, PECL, IIL, TTL, and CMOS (in many types), as well as others I probably don't remember. I find it easier to think of the functions as SSI/MSI rather than TTL, CMOS or whatever.