I just emailed the Hu-friedy company, which is one of the biggest manufacturers of dental instruments. They are always running sales promotions where you turn in so many of your used scalers in exchange for new ones. I asked what they did with all those old scalers, and if there was any kind of program where they could be donated to the military.
You have to understand. Most dentists are cheap. Many dentists would rather send instruments out to get retipped, rather than buy new ones.