If pockets between your gum and teeth are 6mm or higher, then these depths typically require a flap surgery procedure in order to gain the needed access to reach the depth of the deep pockets in order to clean all the toxic tartar off the roots, which was causing all this bone loss in the first place. It also allows access for bone graphs or guided tissue regeneration. This surgery is performed in the office with local anesthetic, and usually oral sedation is also provided to help relax the patient during the procedure. Oral sedation with anti-anxiety medication is safe and effective, and a much less risky procedure than using IV conscious sedation or general anesthesia.
The surgery not only provides access for total tartar removal and bone grafts, but results in lower pocket measurements by reducing the pocket depths by reattaching the gum to the tooth, and this now facilitates the patients ability to reach and effectively clean between the teeth, where prior to the surgery this was impossible.