Not to my knowledge. It has to be a 'natural' critical, not a placate or hidden one. Now, being a stalker, your 'natural' crit rate improves with more teammates, so team more and you'll have build up more
Oddly enough, I have a 35 Kin/Regen and CS seems to crit a LOT for me. That's just me though. About every 4th/5th CS will refresh Build Up for me.
My guides:Dark Melee/Dark Armor/Soul Mastery, Illusion Control/Kinetics/Primal Forces Mastery, Electric Armor
"Dark Armor is a complete waste as a tanking set."
It has a fixed chance to instantly recharge Build Up, not affected by hidden status or nearby allies. So you won't want to use it as an opener from Hide, or after Placate, but it does mean you'll probably want to use the power every time it's up.
The power concentrated strike says that criticals dont do extra damage but refresh build up. So does this mean you can use use concentrated strike from stealth to get an auto crit to refresh build up whenever you want?