Microleakage of class II restoration with zirconia inlay: An in vitro study

Abstract

Background: Class II restoration with zirconia inlay is concerned by numerous studies about the luting coupling between zirconia inlay and teeth. The present study was performed to evaluate the microleakage of Class II zirconia inlayusing two different luting agents and compare to direct restoration using bulk fill composite. Aims: To evaluate the microleakage of Class II restorations using three different techniques. Materials and methods: The study was performed in laboratory with three groups. Each of thirty extracted human teeth was prepared a class II cavity with the same dimensions, then these teeth were randomly divided into 3 groups restored by 3 different approaches. Group 1: zirconia inlay cemented with self-etch resin cement (Multilink N); Group 2: zirconia inlay cemented with resin-modified glass ionomer cement (Fuji Plus); Group 3: direct composite restoration using bulk fill composite(Tetric N-Ceram Bulk Fill). All restorations were subjected to thermal cycling (100 cycles 50C – 55 0C), then immersed to 2% methylene blue solution for 24 hours. The microleakage determined by the extent of dye penetration along the gingival wall was assessed using two methods: quantitative and semi-quantitative method. Results: Among three types of restorations, group 1 demonstrated the significantly lower rate of leakage compared to the others, while group 2 and 3 showed no significant difference. Conclusion: Zirconia inlay restoration cemented with self-etch resin cement has least microleakage degree when compare to class II zirconia inlay restoration cemented with resin-modified glass ionomer cement and direct composite restoration using bulk fill composite. Key words: inlay, zirconia ceramic, class II restoration, microleakage.