Bleaching effect on surface roughness and micro hardeness of composite

This book gives a look on the effect of in office bleaching material on surface roughness and micro-hardness of four composite material and which of these materials did not altered by bleaching. To evaluate the effect of in office bleaching (SDI pola office + 37.5% hydrogen peroxide) on the surface roughness and micro-hardness of four newly developed composite materials that are different in their filler type load and resin matrix. These four materials are: - Filtek Z350XT (noanofilled nanoclusters) 3M /ESPE St. Paul MN USA. - Filtek Z250XT (nanohybrid) 3M /ESPE St. Paul MN USA. - Filtek Z250 (microhybrid) 3M /ESPE St. Paul MN USA. - Filtek P90 (Silorane –based composite) 3M /ESPE St. Paul MN USA.