IN-VIVO EVALUATION OF A FELDSPATHIC CERAMIC SYSTEM - 2-YEAR RESULTS

Objectives: The aim of this clinical study was to evaluate feldspathic ceramic inlays by clinical criteria and quantitative margin analysis, and to compare clinical performance with the quantitative margin anal ysis results. Methods: Fifty fibre-reinforced feldspathic ceramic inla ys were placed in box-shaped, Class II preparations with all margins l ocated in enamel. A low-viscosity type dual-curing resin luting materi al was used for luting. The inlays were evaluated clinically according to modified US Public Health Service criteria after 2 days, 1 year, a nd 2 years. In addition, quantitative margin analysis was performed un der a scanning electron microscope using an image analysing system. Re sults: Clinically the inlays performed very well after 2 years, showin g no changes in colour, no recurrent caries and no marginal discoloura tion. Because of the wear of the composite resin luting material, marg ins were perceptible with an explorer in 54% of the cases after 2 year s. Quantitative margin analysis showed significantly (P less than or e qual to 0.05) more marginal gaps at the composite/ceramic interface co mpared with the enamel/composite interface at each evaluation. There w as a significant increase in marginal gaps at both interfaces during t he first year, whereas marginal gaps at the composite/ceramic interfac e did not increase significantly during the second year. Quantitative margin analysis showed that both time and interface had a significant influence on marginal gaps. Conclusion. Quantitative margin analysis s hould be included in clinical long-term trials on this type of restora tion to recognize possible deficiencies in ceramic, composite resin lu ting material, and the luting interfaces.