Type and time of first re-intervention of posterior restorations - 13-year scenario at the public dental service.

Objectives: We investigated the first re-interventions of two- and three-surface direct restorations on posterior teeth, specifically noting the type and time of the first re-intervention.Materials and methods: In 2002, altogether 5542 posterior two- and three-surface composite and amalgam restorations were done for 3051 patients aged 25-30 years at Helsinki City Public Dental Service (PDS). Based on electronic patient records, we analysed all restorations (n = 2445) having re-intervention during a 13-year follow-up. We recorded the type of tooth, restoration size, and type of first re-intervention. The time to re-intervention was the interval between the date of the placement of restoration at the year 2002 and its first re-intervention.Results: Restorative treatment was the most common (77.9%) first re-intervention, followed by endodontics (11.5%), extractions (5.2%), and other (5.4%). Males, more frequently than females, had extraction or endodontics as first re-intervention. The average time to re-intervention was 5.7 years (SD 3.8; median 5.2). Both median and mean times were shortest for cases involving endodontics or extractions.Conclusions: For the majority of two- and three-surface posterior restorations, the first re-intervention is restorative (replacement or repair of restoration). The shortest time to re-intervention is for restorations that have endodontics or extraction as the first re-intervention.