Microleakage of luting cements in CAD/CAM pediatric zirconia crowns: An in vitro study

Abstract Objectives To assess and compare the microleakage of custom-made zirconia crowns (CZCs) and prefabricated zirconia crowns (PZCs) on primary maxillary incisors when luted with RelyXTM U200, RelyXTM Luting2, and BioCem®. Materials and methods A total of 60 primary maxillary incisors were prepared and divided randomly into two groups of the two types of CAD/CAM zirconia crowns. Within each group, the teeth were further randomised into three subgroups that received different luting cements. After cementation and thermocycling, the teeth were immersed in 2% methylene blue solution. Subsequently, the teeth were sectioned and accessed under stereomicroscope. The data were statistically analysed using two-way ANOVA and post hoc Dunnett T3 tests (p < 0.05). Results PZCs cemented with RelyXTM Luting2 demonstrated the highest microleakage, whereas PZCs cemented with BioCem® exhibited the lowest microleakage. For CZCs, those cemented with RelyXTM Luting2 was significantly greater microleakage than those cemented with BioCem® (p < 0.05). Similarly, PZCs with RelyXTM Luting2 and RelyXTM U200 as luting agents showed significantly higher microleakage compared to those with BioCem® (p = 0.000, p < 0.01, respectively). Furthermore, when using RelyXTM Luting2 as the cement, PZCs had significantly more microleakage than CZCs (p < 0.01). Conclusions BioCem® is recommended as the preferred luting cement, especially for PZCs. Practitioners are advised to critically assess their use of RelyXTM Luting2 due to its elevated microleakage rates with both crown types. Clinical relevance Selecting the appropriate luting cement is vital to minimize microleakage in pediatric zirconia crowns, thereby potentially enhancing the restoration's longevity and clinical success.