Marginal adaptation of ceramic inlays—an in vitro study

Introduction: Class II approximal defects are very common in the clinical practice, in many cases extending subgingivally and beyond the cementoenamel junction (CEJ). For large defects in the posterior region, indirect ceramic restorations provide a better solution than direct composite restorations.Aim: The aim of this experimental in vitro study is to compare the marginal adaptation of hybrid ceramic and lithium disilicate inlays, fabricated using classic and hybrid technique and cemented with two different types of dental cements.Materials and Methods: Forty extracted human molars and premolars were randomly divided into 8 groups and class II cavities (medio-oclusal or disto-oclusal) with the same dimensions were prepared. Hybrid ceramic and lithium disilicate inlays were fabricated according to the manufacturer’s instructions. The marginal gap after cementation was measured using a microscope at 40x magnification. Results: The lowest cement thickness was registered for Group 4—lithium disilicate inlays, classic technique, cemented with composite cement, closely followed by Group 3—hybrid ceramic inlays, classic technique, cemented with composite cement. The highest mean cement thickness values were registered for Group 1—hybrid ceramic inlays, classic technique, cemented with glass ionomer cement, followed by Group 5—hybrid ceramic inlays, hybrid technique, cemented with glass ionomer cement.Conclusion: Under the limitations of this experimental in vitro study, we can conclude the following: lithium disilicate and hybrid ceramic inlays cemented with composite cement have better marginal adaptation than the ones cemented with glass ionomer cement. Lithium disilicate restorations and inlays without cervical margin relocation (classic technique) have a slightly better marginal fit than hybrid ceramic inlays and restorations with hybrid technique. For a more detailed insight, microleakage evaluation should also be carried out