EVALUATING THE MARGINAL FIT OF GALVANOCERAMIC INLAYS: IS IT CLINICALLY ACCEPTABLE?

Purpose: The aim of this study was to investigate the marginal adaptation of galvanoceramic inlay comparing two different ceramic inlays used in dental practice. Materials and methods: Class II inlay cavity was prepared on an ivorine mandibular left first molar and a metal master die was produced from stainless steel. Using electroforming machine, fifteen galvanoformed copings were produced firstly, and then galvanoceramic inlays were obtained by firing feldspathic porcelain on them. For comparison with ceramic inlays, two different groups were prepared from lithium disilicate and alumina ceramic. The absolute marginal discrepancy of galvanoformed copings and three different inlay restorations were measured onto the master die in described 16 different reference points by scanning electron microscope. Data obtained from the measurements were statistically analysed using paired t-test and one-way analyses of variance (α=.05). Results: The galvanoceramic inlays showed a significantly higher marginal discrepancy than other ceramic inlays (P<.001). The mean marginal discrepancy was 379±153µm for galvanoceramic inlays, whereas other inlays had marginal gaps under 200µm. Galvanoformed copings had lowest marginal gap, but the adaptation of these copings was failed after porcelain firing. Conclusion: Galvanoformed copings have superior marginal fit than other ceramic inlays, but the marginal gaps increased after porcelain firing and marginal adaptations became clinically unacceptable. Clinical usage of galvanoceramic inlays is questionable due to their marginal discrepancies.