Objective: The aim of this retrospective study was to evaluate the long-term clinical outcomes of posterior composite resin sandwich restorations, and secondarily to assess the influence of potential factors on survival and causes of failure.
Method And Materials: Two hundred and four posterior Herculite XRV restorations due to primary caries performed between 1991 and 1997 were included. The restorations were assessed after 18 years, by two calibrated examiners, according to USPHS criteria.