Factors Affecting Tooth Color - Tooth color influenced by factors such as light reflection, absorption, and transmission - Brightness of a tooth can change based on background color and brightness - Intrinsic color and extrinsic stains affect overall appearance of teeth - Scattering and absorption of light within enamel and dentine determine intrinsic color

Types and Causes of Tooth Discoloration - Tooth discoloration categorised as intrinsic or extrinsic stains - Intrinsic stains cannot be removed through regular dental cleaning - Extrinsic staining caused by factors like smoking, pigments in food and beverages, antibiotics, and metals - Dental plaque can become stained by chromogenic bacteria - Prolonged plaque accumulation can lead to enamel demineralization and formation of white spot lesions

Extrinsic Staining - Extrinsic staining mainly caused by environmental factors - Pigments from smoking, beverages, and foods can be adsorbed into dental pellicle or directly onto tooth surface - Dental plaque, a biofilm of bacteria, can become stained by chromogenic bacteria - Neglected plaque can calcify and form calculus, a hard deposit on teeth - Tar from tobacco products can form a yellow-brown-black stain on teeth

Intrinsic Staining - Intrinsic staining caused by factors within tooth structure - Age, decay, orthodontic white spot lesions, fluorosis, amalgam restorations, tetracycline stain, genetic conditions, and non-vital coloring can cause intrinsic staining - Secondary dentin formation and enamel thinning contribute to tooth darkening with age - Tooth shade not influenced by gender or race - Intrinsic staining cannot be removed through regular dental cleaning

Whitening Treatments - Hydrogen peroxide most commonly used active ingredient in whitening products - Hydrogen peroxide acts as oxidizing agent, breaking down to produce unstable free radicals - Free radicals attach to organic pigment molecules in tooth enamel, resulting in whitening effect - Dental professionals should correctly diagnose type, intensity, and location of tooth discoloration for successful whitening treatment - Time exposure and concentration of bleaching compound determine tooth whitening endpoint