Longevity of glass ceramic inlays and amalgam--results up to 6 years

Ceramic inlays are discussed as one option for the substitution of amalgam restorations. The purpose of this study was to determine the longevity of glass ceramic inlays and amalgam restorations placed by the author: 123 class I and class II Dicor inlays placed with adhesive techniques and 163 amalgam class I and class II restorations were investigated. The observation time for the inlays varied from 4 to 82 months. The inlays were clinically investigated using modified USPHS criteria and documented photographically. Kaplan-Meier statistics were used to calculate the survival rate. From the 123 evaluated inlays 12 inlays (9.7%) failed: 7 due to fractures, 4 because of endodontic problems and 1 inlay was replaced due to persisting postoperative pain. All fractures could be explained by case selection errors. According to the Kaplan-Meier method, the estimated success rate after 6 years was 76% for the Dicor inlays and 87% for the amalgam restorations (control group). The difference was not statistically significant. It was concluded that Dicor inlays may be used as a successful alternative to amalgam.