What do you recommend for interproximal reduction in Invisalign patients?

There are several good products out there for interproximal reduction for Invisalign cases. There are always the traditional diamond strips if you want to open spaces by hand. Brasseler USA makes some nice diamond finishing strips. Also, there are several rotary systems that are very good. There is a Kavo handpiece called INTRAcompact 2061 CHC that comes with an ortho strip set called Intensiv ORtho-Strips Set by Intensiv SA in Switzerland. This system works very well and has a pivoting head on the handpiece so that you can turn the vibrating strips in any direction that works best. We use this system in our office. Another good system that has gotten good reviews is Interproximal Enamel Reduction OS Discs (Komet). It is also a handpiece with a large diamond strip that is attached.  In my office, I use a combination of hand stripping and the handpiece if I have a lot to remove. The hand strips are very conservative and can get the reduction started without causing ledging. Once the contact has been broken with hand strips, I go to the handpiece for more gross reduction if needed.