title: Periapical resurgery versus periapical surgery: a 5-year longitudinal comparison.
abstract: OBJECTIVE
  To monitor and compare the outcome of periradicular surgery in teeth that had previously undergone surgical treatment versus teeth that were undergoing a surgical procedure for the first time.
  
  
  METHODS
  A total of 164 patients with 231 roots with previously unresolved periapical lesions were followed for up to 5 years following surgery. In all, 162 roots had received unsuccessful conventional root canal treatment (group AS) and 69 had been treated previously using apical surgery (group RS). The surgical procedure was completed using ultrasonic retrotips to prepare the apical root-end cavity, and a zinc-oxide EBA reinforced material was used to fill the apical root-end cavities. Lesions were radiologically examined from 1 to 5 years following the surgical procedure. Radiographs were independently analysed, according to a previously published classification.
  
  
  RESULTS
  In all the roots examined after 5 years, the overall healing rate was 78%; in group AS, 140 (86%) healed with complete bone filling of the surgical cavity, 12 (7%) were considered to have incompletely healed and 10 (6%) were associated with post-treatment disease. In group RS, 41 (59%) healed completely, 12 (17%) were considered to have incompletely healed and 16 (23%) were associated with post-treatment disease. The difference between a second surgical procedure and a first surgical procedure was statistically significant (Mann-Whitney U-test, P=0.001).
  
  
  CONCLUSIONS
  Surgical retreatment of teeth previously treated with surgery is a valid alternative to extraction. However, association with post-treatment disease was greater than after a primary surgical approach.
authors.affiliation: Clinica Odontoiatrica, D.M.C.O. San Paolo, School of Dentistry, University of Milan, Milan, Italy. massimo.gagliani@unimi.it
authors.forename: M M
authors.initials: MM
authors.lastname: Gagliani
authors.forename: F G M
authors.initials: FG
authors.lastname: Gorni
authors.forename: L
authors.initials: L
authors.lastname: Strohmenger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001047:Apicoectomy; D017220:Dentin-Bonding Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010483:Periapical Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D012008:Recurrence; D012086:Reoperation; D012184:Retrograde Obturation; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods; D012390:Root Canal Therapy; D016896:Treatment Outcome; D014464:Ultrasonic Therapy; D014945:Wound Healing / Q000502:physiology; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D017220:Dentin-Bonding Agents; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C084074:Super EBA