Comparative study of some mechanical properties of different composite resins

Objective: The aim of this in vetro study is to determine the differences ofsome mechanical properties between Bulk Fill and conventional composite resins.
Material and Methods: Two Bulk Fill and one conventional composite materials were used with a total of 60 samples prepared in a 6*4 mm length cylindrical metal mold and divided into three groups of different composite resin conventional increment, high viscosity and low viscosity BulkFill. 3M Filtek®, Tetric N Ceram BulkFill® and SDR® respectively. Instron Universal Testing Machine used to test the samples at 1mm/min Ramp Rate with 5 kN Cell Load, reading conducted by the computer and printed directly. Using SPSS21 to analyze the data.
Results: Statistical analysis was performed using one way ANOVA and Tukey Post Hoc tests (P < 0.0005). The high viscosity Bulk Fill group performed with almost the same as the incremental conventional placement in the load and stress with no significance statistical difference (P < 0.0005), whereas the low viscosity Bulk Fill had inferior significance statistical difference than the conventional and  high viscosity.
Conclusions: Using the high viscosity Bulk Fill composite resins would represent some of the mechanical function of the traditional composite with benefits of saving the time.