Effects of staining and bleaching procedures on the optical and surface properties of CAD-CAM materials.

Purpose: To examine the effects of coffee staining and bleaching applications on the optical properties of CAD-CAM blocks, and to provide a three-dimensional visualization of surface changes with atomic force microscope (AFM).

Methods: 80 samples were prepared from four different CAD-CAM blocks: [Cerec (CR), Shofu (SH), Cerasmart (CRS), Lava Ultimate (LU)], and a microhybrid composite resin [Filtek Z250 (Z250)]. After staining, the samples were divided into two subgroups according to bleaching methods: 16% carbamide peroxide (HB), and 40% hydrogen peroxide (OB).