Mazak for example, the base unit cost is roughly 450kusd, built in kentucky, but Optional extra is the Mazak brand of onboard CAM, meaning you do all the calculations of the part at the controls of the machine, not on a PC. for this, i was quoted something like 15k usd and none of it is useful to dental. you would have to buy the Mazak CAM, AND ALSO buy an offline CAM like Hyperdent or WorkNC to do the milling, with the caveat that neither of these programs come equipped to mill a custom size part - you can mill standard sized cylinders or cubes but not predefined blocks. and for this application you'll need these CAM suites to be able to use your part AS the block to begin with. so this is already a non starter because of the inherent software limitations.
so you've spent half a million now on a machine and software that can work together but not for the purpose it appears it was capable of doing to begin with.
so don't even begin down this road without being committed to losing a year of your time developing the solution you want - nobody makes it and the CAM companies will sell you unlocked software but you have to write the toolpaths yourself.