title: Four-year outcomes of restored posterior tooth surfaces-a massive data analysis.
abstract: OBJECTIVE
  There is only sparse knowledge concerning the outcomes of treatments with posterior permanent restorations in general practice settings. This study aimed at evaluating outcomes based on a large dataset by using a novel approach on a tooth surface basis.
  
  
  METHODS
  The study based on routine data from a major German national health insurance company. Respective treatment fee codes allowed for tracking the clinical courses on a tooth surface level. The study intervention was defined as the placement of a restoration on an interproximal or occlusal posterior tooth surface regardless of its actual extension and material on which no information was available. All surfaces restored between January 1st, 2010 and December 31st, 2013 were included. Kaplan-Meier survival analyses were conducted to estimate four-year survival. The primary outcome was a restorative re-intervention on the same tooth surface. Separate analyses were performed for the secondary outcomes "crowning" and "extraction".
  
  
  RESULTS
  Over ten million interproximal surfaces and eight million occlusal surfaces in nine million posterior teeth had been restored. At 4 years, the cumulative survival rates concerning the primary outcome "re-intervention" for mesial surfaces (81.4%; CI 81.3-81.5%) and distal surfaces (81.2%; CI 81.1-81.2%) differed significantly from those for occlusal surfaces (77.0%; CI 76.9-77.0%). Restored surfaces in premolars showed significantly higher survival rates compared to molars. Four-year survival rates for the secondary outcome "crowning" were 91.9% (CI 91.8-91.9%) for mesial surfaces, 92.1% (CI 92.1-92.2%) for distal surfaces and 93.3% (CI 93.2-93.3%) for occlusal surfaces. The respective rates for the secondary outcome "extraction" were 94.5% (CI 94.5-94.5%) for mesial surfaces, 94.8% (CI 94.7-94.8%) for distal surfaces and 95.4% (CI 95.4-95.5%) for occlusal surfaces.
  
  
  CONCLUSIONS
  Re-interventions after restorative treatment play a significant role in general practice settings. Surface-related survival rates of restorations reveal a need for improvement.
  
  
  CONCLUSIONS
  This study allows the estimation of the probability of re-interventions after restoring posterior tooth surfaces. It is based on several million cases from general practises under the terms and conditions of a national health insurance system.
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany. Michael.Raedel@uniklinikum-dresden.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Raedel
authors.affiliation: AGENON Gesellschaft für Unternehmensentwicklung im Gesundheitswesen, Friedrichstraße 94, 10117, Berlin, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: AGENON Gesellschaft für Unternehmensentwicklung im Gesundheitswesen, Friedrichstraße 94, 10117, Berlin, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Bohm
authors.affiliation: AGENON Gesellschaft für Unternehmensentwicklung im Gesundheitswesen, Friedrichstraße 94, 10117, Berlin, Germany.
authors.forename: Heinz-Werner
authors.initials: HW
authors.lastname: Priess
authors.affiliation: Policlinic of Prosthetic Dentistry, Gerodontology and Biomaterials, Center of Oral Health, University Medicine Greifswald, Rotgerberstraße 8, 17475, Greifswald, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Samietz
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Konstantinidis
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Walter
mesh_terms: D057225:Data Mining; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data*; D005792:General Practice, Dental; D005858:Germany; D006302:Health Services Research; D006801:Humans; D007347:Insurance, Dental; D019233:Retreatment; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Dental filling; Dental restoration (permanent); General practice (dental); Health services research; Operative dentistry; Public health; Treatment outcome