ABSTRACT
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). Color measurements were performed at baseline (t0), after staining (t1), and after bleaching (t2) to obtain translucency parameters (TP00), color change (ΔE00), and whiteness index (WID) values. Surface roughness analysis (Ra) was performed with AFM after coffee staining and bleaching procedures (at t1 and t2). Data were analyzed with Generalized Linear Model, and Bonferroni correction (P< 0.05). RESULTS: TP00 values increased only in the CRS group after the bleaching application, and the effect of method was again observed only in CRS. While bleaching increased WID values of all groups except CRS, no difference was found between bleaching methods. Regardless of evaluation time, the roughest group is Z250, and the only difference between bleaching methods was observed in the CR group. In conclusion, the effects of staining and bleaching applications on the optical and surface properties of CAD-CAM blocks are material-dependent. CLINICAL SIGNIFICANCE: Effective bleaching of discolored CAD-CAM materials was achieved regardless of the bleaching method used, and without any significant adverse effect on the surface properties of the materials.
Subject(s)
Coffee , Composite Resins , Materials Testing , Color , Ceramics , Staining and Labeling , Surface Properties , Computer-Aided DesignSubject(s)
Coronary Artery Bypass , Pulse , Retina , Retinal Vessels , Tomography, Optical Coherence , Female , Humans , MaleSubject(s)
Central Nervous System Cysts/diagnosis , Central Nervous System Cysts/surgery , Eye Abnormalities/diagnosis , Eye Abnormalities/surgery , Fingers/abnormalities , Skin Abnormalities/diagnosis , Skin Abnormalities/surgery , Central Nervous System Cysts/complications , Encephalocele/complications , Encephalocele/diagnostic imaging , Encephalocele/surgery , Eye Abnormalities/complications , Fingers/surgery , Humans , Infant, Newborn , Male , Skin Abnormalities/complications , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: The aim of this study was to investigate the association between knee osteoarthritis (OA) and bone mineral density (BMD) in the femur and lumbar vertebrae. MATERIALS AND METHODS: A total of 74 female patients (mean age 61.9 ±9.1 years, mean body mass index 27.09±4.24) diagnosed with knee OA were included in this study. To assess knee OA, bilateral weight-bearing antero-posterior knee radiographs were taken and graded from 0 to 4 according to Kellgren-Lawrence criteria. The BMD of the subjects was measured using dual-energy X-ray absorptiometry (DEXA). BMD measurements of those with OA were compared with those without OA. RESULTS: While there was no correlation between BMD and the grade of knee OA, a significant negative correlation was found between age and femur BMD. Body mass index was positively correlated with OA and negatively correlated with OP. CONCLUSION: Further investigations are needed to demonstrate the association between knee OA and BMD.
