AN IN-VITRO STUDY OF MICROLEAKAGE OF A NEW ORMOCER BULK-FILL COMPOSITE RESIN

Objectives: Over the last 30 years, manufacturers have focused on reducing the shrinkage stress generated in resin based composites (RBC) materials and increasing the strength by exploring beyond Bis-GMA matrix. The use of Ormocer as the matrix in composite resins is considered as an alternative method in obtaining low-shrinkage resins with improved mechanical properties. Moreover, in an effort to reduce RBC placement time and technique sensitivity manufacturers have introduced bulk fill flowable base materials and/or bulk fill restorative materials. The objective of this study was to assess the microleakage of a new Ormocer-based bulk fill composite in class II cavity preparations.
Methods: Class II cavity was prepared on 30 caries free ,extracted human molars teeth. All teeth were randomly divided into 3 groups(n=10) according to the composite to be used as follow : Group 1 was restored with Ormocer-based bulk fill RBC (Admira Fusion x-tra, VOCO ) Group 2 was restored with nanohybrid bulk fill RBC (Tetric N-ceram bulk fill, Ivoclar Vivadent ) and, Group 3 was restored with universal nanohybrid RBC (Filtek Z350 XT, 3M ESPE ) which served as a control group. Microleakage was evaluated using stereo-microscope after staining and thermocycling.
Results: Results were reviewed with ANOVA and Kruskal–Wallis Tests. Statistically significant difference was found between the average of microleakage scores of the three tested materials (p < 0.01). However, there was no Statistically significant difference between Admira Fusion X-tra and the control group regarding the occlusal (P=0.502) or cervical (P=0.689) walls. The microleakage values were the greatest for Tetric N-ceram bulk fill and least for Filtek Z350 xt with Admira Fusion X-tra ranked between the two.
Conclusions: Ormocer based composite filling material showed an acceptable results in direct class II composite restorations even in bulk filling technique.