title: Treatment history of teeth in relation to the longevity of the teeth and their restorations: outcomes of teeth treated and maintained for 15 years.
abstract: BACKGROUND
  Limited clinical data exist on the survival of teeth relative to their treatment history.
  
  
  OBJECTIVE
  This study evaluated failure of teeth relative to their treatment history.
  
  
  METHODS
  Longitudinal data were collected for 3071 teeth from 148 fully compliant patients from 1 private practice in Yamagata, Japan. Follow-up times ranged from 15 to 23 years, with a mean of 19.2 years (SD 2.4). In this study, every tooth and its restoration were evaluated by one of the authors at the time of each maintenance visit. Treatment history of the teeth was categorized at baseline as follows: (1) sound, unrestored tooth (SUT); (2) 1-surface restoration (RT1); (3) 2-surface restoration (RT2); (4) 3-surface restoration (RT3); (5) 4+-surface restoration (RT4); (6) complete crown (CCT); (7) abutment for fixed partial dental prosthesis (AFT); (8) abutment for removable partial dental prosthesis (APDT); and (9) root canal treatment (RCT). Three types of failure modes were evaluated in this study: (1) restorative failure (secondary caries and/or fracture), (2) extraction, and (3) any failure (restorative failure or extraction). Multivariate survival analysis was used to determine the impact of the treatment history on failure (alpha=.05).
  
  
  RESULTS
  Teeth with multi-surface restorations experienced the highest incidence of any failure (P<.001). For secondary caries, similar risks were noted for the different treatment histories. For failures resulting in extraction, the only teeth with an increased risk were abutments for removable partial dental prostheses (relative risk=5.5) (P=.008).
  
  
  CONCLUSIONS
  The data demonstrated that restored teeth experienced a higher incidence of failure compared with unrestored teeth. Complete crowns and abutments for fixed partial dental prostheses had fewer restorative failures when compared with teeth with complex multisurface restorations. Removable partial denture abutments experienced the highest failure rate.
authors: Department of General Dentistry, Division of Periodontology, Goldman School of Dental Medicine, Boston University, Boston, MA 02118, USA.
authors: Takanari
authors: T
authors: Miyamoto
authors: Steven M
authors: SM
authors: Morgano
authors: Takashi
authors: T
authors: Kumagai
authors: Judith A
authors: JA
authors: Jones
authors: Martha E
authors: ME
authors: Nunn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003442:Crowns / Q000706:statistics & numerical data; D000044:Dental Abutments / Q000706:statistics & numerical data; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D006801:Humans; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D012390:Root Canal Therapy / Q000706:statistics & numerical data; D016019:Survival Analysis; D014081:Tooth Extraction / Q000706:statistics & numerical data*