Filtek p90

The tooth fragments were randomly assigned to three groups (n=30) according to the adhesive systems described in Table 1. The adhesive systems were applied strictly according to the manufacturers' instructions and composite blocks were fabricated on the dentin surfaces in four 1-mm increments. The composite Filtek P90 (3M-ESPE, St Paul, MN, USA) shade A3, was used for the P90 adhesive system group and Filtek Z350 (3M-ESPE) shade A3, was used for the other groups. Each increment of composite was light activated for 40 s at 510-540 mW/cmfoot_1 using a quartz tungsten halogen unit (Optilux 501; Demetron/Kerr Corporation, Orange, CA, USA). The curing unit irradiance was monitored using a radiometer (Model 100; Demetron).

3D cube models of the composite materials (length × breadth × height of 0.0375 mm 3 ) with resin matrix and filler particles were simulated.[ 10 ] The filler shape was kept as a standard sphere, and the distance between the filler particles was also kept constant; only the filler size and percentage and radius of spherical indenter for testing were varied for each group [Table 1]. T1-6 Table 1: Parameters for wear resistance and compressive strength Group I -silorane (Filtek P90, 3M ESPE, India); (n = 10) Group II -microhybrid (Z250, 3M ESPE, India); (n = 10). Group III -nanohybrid (Z350, 3M ESPE, India); (n = 10) WR was calculated as (K W L)/H, where K is the dimensionless constant, W -force applied in Newtons, Lsliding length in mm, and H -hardness of the material.
For CS testing, instead of a spherical indenter, forces applied by Instron Universal testing machine were simulated. The deformation in millimeter on application of increasing loads was obtained, and the compressive stress in MPa was calculated as the load/cross-sectional area. [ 11 ]