While EDM and MDM evolved from the same breakthrough in technology, they are different methods using the same concept.
If you are not sure if you need MDM or EDM here is a comparison of the two methods.
Electrical discharge machining (EDM) may be referred to as spark eroding and includes many sub-categories including die sinking and wire erosion. These machines create a spark and two electrodes to create fine cuts or holes. These machines tend to be very expensive.
Metal disintegrating machines were developed specifically to disintegrate out broken tooling such as broken bolts, broken taps, broken pins and more. These machines also use a spark but do not use two electrodes, just one. A variety of electrode sizes, shapes and materials can be used to accomplish the task of removing broken tooling and saving the part they are broken in. This process saves hours of time attempting to use something like easy out to remove the broken tooling. It has been proven to save thousands of dollars for industries including power industries, aerospace companies, oil and gas companies and in military applications as well.
Some newer machines are available on the market and are appealing because of their cheap price, but these machines do not remove broken tooling in minutes like Electro Arc metal disintegrators, they are not long-lasting machines and they can end up costing more money in the long run.