My periodontist maintains a pretty good website that explains all these
questions
http://www.periodoctors.com/index2.htm
Here is how I understand it: flap surgery, bone graft, rooting and
scaling and emdogain treatment are typically all done during one
surgical procedure, all are done to reduce gum pocket size, clean your
teeth in areas typically not reachable by you, treat the teeth to
reduce the possibility of more bacteria built up, and try to regenerate
some of the lost bone and supporting tissue. I think it costs about
1500 dollars for one quadrant of your teeth. Done properly it will
reduce your pocket size to a manageable depth for easier cleaning and
raise your bone level up to 2mm ? depending the type of your bone
defect.