objectives: the aim of this study was to evaluate the effect of six herbal teas on the color stability of two types of nanohybrid and one microhybrid resin composite.  materials and methods: 70 disc-shaped specimens, 210 in total (7*2mm), were fabricated from each of the following materials in metal mould : tetric n ceram, grandio, gradia direct anterior. specimens were stored in distilled wate...

■ SPECTROPHOTOMETRY AND PHOTOMETRY Beer’s Law Spectrophotometric Instruments Components of a Spectrophotometer Spectrophotometer Quality Assurance Atomic Absorption Spectrophotometer Flame Photometry Fluorometry Chemiluminescence Turbidity and Nephelometry Laser Applications ■ ELECTROCHEMISTRY Galvanic and Electrolytic Cells Half-Cells Ion-Selective Electrodes pH Electrodes Gas-Sensing Electrod...

Introduction: The aim of the study was to evaluate the sustained release effect of 2% chlorhexidine and its combination with 2% chitosan, in vitro. Method: The sustained release effect of chlorhexidine and its combination with chitosan was determined using a UV spectrophotometer. Results: UV spectrophotometer analysis for the sustained release of chlorhexidine showed that almost 100% of chlorhe...