Abstract: Endodontic surgery is a valuable option for maintaining patient’s natural dentition when previous orthograde endodontic treatments fail to succeed. Generaly, the surgical success rate can be up to 90%. Several factors are associated with the outcome of the surgery. Theoretically, the general health or systemic illness which affect the healing up of the wound are related to the surgery prognosis, such as diabetes, anemia, radiation treatment etc. Besides, the tooth position, the bone defect situation, whether the bone defect is through with the periodontal pocket, preoperative root canal treatment etc, are also associated with the surgical outcome. Before the surgery, serious examination, proper surgical devices and materials should be prepared, because it intensely affects the surgical success rate. Aesthetic factors should also be taken in account during the operation. To obtain better aesthetic results, design of the approach mucosal flap is the key point. Of all the factors involving the prognosis of endodontic surgery, retro-filling materials and magnified devices is considered the major factors in some articles. The factors related with endodontic surgery are various, but how they act with each other is still unknown. To answer this question, further research is necessary.

Key words: endodontic surgery, root canal treatment, prognosis factor