Microleakage of Nano/Microhybrid Composites in Class II Restorations

Objective: To compare the microleakage at the enamel and dentine/cementum margins of three nanocomposites and one microhybrid composite in Class II restorations. Materials and Methods: Four light-cured dental resin restorative materials in combination with their respective bonding agents were investigated. Eighty non-carious, extracted human molars were divided into 4 groups of 20 teeth each. The apices of the teeth were sealed with a resin modified glass ionomer cement. Class II slot cavities (3 x 5 x 2 mm) were prepared on the proximal surfaces of each tooth. Each group had an equal number of cavities with gingival margin on enamel and on dentine/cementum. Restorations were placed as indicated: Group 1 (G1): Ceram X + Prime & Bond NT (Dentsply), G2: Premise + Optibond Solo Plus (Kerr), G3: Grandio + Admira Bond (VOCO), G4: Z100 + Adper Scotchbond (3M ESPE). After thermocycling and immersion in 0.5% methylene blue dye solution, the teeth were sectioned and dye penetration was scored on a scale of 0 to 3 on both the enamel and dentine/cementum margins. The data was analyzed with Kruskal-Wallis one way ANOVA and Mann-Whitney test at ranks (significance at p<0.05). Results: In the enamel group: Group 4 differed significantly from all the other groups. In the dentine/cementum group: Groups 1 and 2 differed statistically significantly from groups 3 and 4. There was also a statistically significant difference between groups 3 and 4. Conclusion: Within the limitations of this study no material was able to eliminate microleakage at the dentine/cementum margin. Grandio + Admira Bond showed the best marginal sealing ability as compared to the other tested materials. At the enamel margins, all tested materials performed equally well except Z100 + Adper Scotchbond that showed the largest microleakge.