User blog comment:Xilinoc/Ch. 591 - Marching Out the ZOMBIES 2/@comment-24153155-20140730134113/@comment-11051098-20140731123250

Yeah, me neither. Mayuri can create serums to grow back his own damaged body parts, who knows just how far he's able to take it.

Seeing as the revived Arrancars seem to have been completely revived, with personalities and all intact and maybe even stronger than ever before, Mayuri must have been able to completely revive them, just the way Orihime would restore a dead person 100 % by rejecting the event that killed them.