my dad bought new dental software called eaglesoft. it uses a sql server to store all of its stuff. it stores everything in a .log and .db file. it fires up the sql database in the morning and then we can use the program from there. it hasn't crashed yet his old software, tdocs, didn't seem to use sql, actually i'm not sure how it stored everything, it just kept growing bigger and bigger over the years and generated thousands of .fil files. it was somewhat stable, although he would occasionally get an overflow error that would knock him out of the program i'm sure it's purely based on how good the sql programming is... shit was expensive too, like $10k for a single dentist. compare that to his old software that cost $800.