Longevity of 2- and 3-surface restorations in posterior teeth of 25- to 30-year-olds attending Public Dental Service-A 13-year observation.

Objectives: The aim of this patient document-based retrospective study among 25- to 30-year-old Finnish adults was to evaluate longevity of 2- and 3-surface posterior restorations according to type of tooth, size of restoration, and restorative material used.

Methods: Data were extracted from electronic patient files of the Helsinki City Public Dental Service (PDS), Finland. A total of 5542 2- and 3-surface posterior composite and amalgam restorations were followed indirectly from 2002 to 2015.