Marginal Microleakage of Monolithic Zirconia Crowns Using Different Marginal Cement Space Thickness and Luting Cements
Author(s): Muthanna Ibrahim Nayyef* and Adel Farhan Ibraheem
Abstract
Aims: The aim of this study was to evaluate the effect of different marginal cement space thickness and different luting agents on the microleakage of monolithic zirconia crown restorations. Materials and methods: forty-eight human first premolars were prepared to receive full anatomic crowns milled from KATANATM zirconia disc, divided into two main groups (n=24) based on different marginal cement space thickness; Group A- zero μm marginal cement space and Group B- 25 μm marginal cement space. Each group was then subdivided into three subgroups (n=8) based on the luting agent used: (A1, B1) cemented with RelyX Ultimate adhesive cement, (A2, B2) cemented with RelyX U200 self-adhesive cement and (A3, B3) cemented with Riva Luting Plus Resin-modified glass ionomer cement. After cementation and thermocycling (500 cycles), the samples were then emersed in 2% methylene blue for 24h. Before sectioning the samples bucco-palatally each sample was embedded in clear epoxy resin. Microleakage was recorded using a digital microscope at 40X. The data was statistically analyzed using One-Way ANOVA and post hoc Bonferroni tests. Results: the result of this study showed that the marginal cement space thickness had a significant effect on microleakage (p ≤0.05). Furthermore, the type of luting agent had a significant effect, with RelyX ultimate luting agent showing the least microleakage. Conclusion: increasing the marginal cement space thickness to 25 μm reduced the amount of microleakage of zirconia crown restorations. RelyX Ultimate adhesive resin cement showed the lowest amount of microleakage when compared to the other types of luting cements.