title: Factors influencing the outcome of root-resection therapy in molars: a 10-year retrospective study.
abstract: BACKGROUND
  Root resection is one treatment option for preserving molars with furcation involvement. This study evaluated the prognosis of root-resection therapy retrospectively and examined the factors influencing the survival rate of resected molars.
  
  
  METHODS
  Root-resection therapy was performed on 691 molars in 579 patients. The associated factors were examined from 342 of 402 molars that had been followed up for >1 year. Survival analysis was used to statistically analyze the factors.
  
  
  RESULTS
  Over the past 10 years, 102 of 342 cases (29.8%) failed. The factors were classified into four groups and analyzed to determine their influence on the survival rate of the resected molars. Regarding the resection-related factors, the molars resected because of periodontal problems had a higher survival rate than those resected because of non-periodontal problems (tooth fracture, dental caries, and endodontic problems; P = 0.0097). Patient- and tooth-related factors had no effect on the survival rates. Among the site-related factors, only the amount of bone support of the remaining roots at the time of surgery had a significant effect on the survival rate in the group of molars with periodontal problems (P = 0.0269).
  
  
  CONCLUSIONS
  Root resection to treat periodontal problems had a better prognosis than for non-periodontal problems. To achieve a good result, it was important that the remaining roots had >50% bone support. This guideline may help to improve the predictability of root-resection therapy.
authors.affiliation: Department of Periodontics, The Institute of Oral Health Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Seung-Yun
authors.initials: SY
authors.lastname: Shin
authors.forename: Seung-Min
authors.initials: SM
authors.lastname: Yang
authors.forename: Seung-Beom
authors.initials: SB
authors.lastname: Kye
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000473:pathology; D055113:Chronic Periodontitis / Q000601:surgery; D000044:Dental Abutments; D003731:Dental Caries / Q000628:therapy; D003788:Dental Pulp Diseases / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D017823:Furcation Defects / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000601:surgery*; D010483:Periapical Diseases / Q000601:surgery; D012189:Retrospective Studies; D012907:Smoking; D015996:Survival Rate; D019227:Tooth Apex / Q000473:pathology; D014082:Tooth Fractures / Q000601:surgery; D014092:Tooth Root / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult