The definition of retrograde endodontic treatment, apexectomi, is removal of periapical pathology due to failure of root canal treatment. Non-healing periapical pathology associated with endodontically treated teeth is customarily managed by retreatment of the previous therapy. Root-end resection or retrograde endodontic treatment is less often the first optional treatment. The treatment might be the option after an unsuccessful retreatment or if retreatment is impossible. Retrograde endodontic procedure involves laying of flaps and removal of tissues from outside the root canal space, including bone, periodontal membrane, and periosteum . After root end is exposed and detected with microscope, there are possibilities to examine and recognize the pathology behind the periapical pathosis, and thereafter a proper treatment. Retrograde endodontic surgery may induce postoperative pain, oedema and discoloration, which is all reversible. Contraindication Beside local contraindication there are general contraindications were the medical condition is complex and must be discussed with the patient’s doctor. The local contraindications are: poor periodontal support non-restorable tooth poor access Surgical procedure A successful treatment of a periapical surgery is depended on the hemostasis among other factors. Hemostasis is essential for better visualization and good environment for replacing of the retrograde filling material. A good hemostasis-agent makes the hemostasis easy to achieve and manipulate, is biocompatible, does not impair healing, is reliable and is relatively inexpensive. There are different ways to achieve hemostasis; one is through pre-surgical local anesthetic with 2-3 carpules of epinephrine with multiple infiltration sites, the other is during surgery. Putting a sterile cotton pellet dipped in epinephrine into the bony crept after removal of granulation tissue. When an optimum hemostasis is achieved the flap can be raised. There are three different incision-methods; a) intrasulcular flap, b)submarginal flap, c) semilunar flap or vertical incision. Intrasulcular Intrasulucular flap extends along the gingival sulcus of the tooth being treated. There is a vertical incision at each end, which should give sufficient access to the root end these two cuts are united with a sulcus incision. This flap provides a good visualisation for the surgeon and the blood supply to the flap is being kept. The flap is elevated and access to the apex foramina is achieved with an elevating instrument (Norbergs Raspatorium). Postoperative pain and swelling are usually minimal. A possible disadvantage is gingival recession, this is normally a concern in the anterior region. Palatal flaps are only used for treatment of palatal roots of molars or premolars. The incision involves several teeth along their gingival sulcus. Here there is a need of carefulness to not damage the palatine neurovascular bundle. Submarginal The submarginal flap is made in the attached gingiva and follows its contours. This flap cannot be used in the mandible because of restricted width of the attached gingiva. The reason of choosing this flap is when the gingival tissue should be undisturbed, particulary adjacent to a crown. The flap should be minimized as possible to prevent ischemia of the remaining attached gingiva. The semilunar incision is entirely in the alveolar mucosa and is curved at its ends. This method is not widely used because of the small surgical access and the cause of ischemia . Vertical incision This is made vertically over the root and is reflected vertically over the apex. This does not cut the vessels off and could be used if the roots are long, but the surgical access is limited and the incision may directly lie over the blood clot in the bony cavity. Root-end resection If any reverse filling is to be done, the root tip has to be prepared to receive the filling material. In the past, the preparation was made with burs, diamond stone and carbide burs. In the beginning of 1990s the ultrasonic devices became available, which has become more and more effective and relevant in the apical surgery. The ultrasonic tip is smaller than the burs, that were usually used. This tips converse tooth structure and give more parallel preparation that makes the root end filling more precise and decrease the risk for microbacterial leakage. The ultrasonic tips allows the operator to make very precise preparations, because of the ease which it removes old gutta-percha and the way it cleans and widen canals narrowed by reparative dentine to make an excellent shape for the apical sealant. Root-end filling materials The purpose of a root-end-seal material is to prohibit bacterial invasion from the remaining intra-radicular pulp-tissue into the periradicular space and to prohibit intrusion of blood serum into the apical foramina. Other functions of an optimum apical seal are, insolubility in the tissue fluid and high dimensional stability. It should also adhere and adapt to the dentine walls of the preparated root end, prevent leakage of microorganism and be biocompatible. A great variety of different materials have been suggested as apical sealants; amalgam, glass ionomer cement, gutta-percha, zinc oxide-eugenol based matrix, composite resin, MTA,cavit (eugenol-free temporary filling) .