Teeth discolouration is not a matter to be taken lightly because it can show that there is something wrong with your teeth and therefore with your health. Teeth discolouration is when the enamel (the hard, outer surface of the tooth) or the dentine (the layer below the enamel) becomes discoloured. Food, drink and smoking also stain the teeth.
The coronal portion of the tooth consists of enamel, dentine and pulp. Any change to these structures is likely to cause an alteration in the outward appearance of the tooth caused by its light transmitting and reflecting properties. Many different things can cause tooth discolouration. The change in colour may affect the entire tooth, or just appear as spots or lines in the tooth enamel. Your genes influence your tooth colour.
Inherited diseases may affect the thickness of enamel or the calcium or protein content of the enamel, which can cause colour changes. Metabolic diseases may cause changes in tooth colour and shape.
Drugs and medications either taken by the mother while pregnant or by the child during the time of tooth development can cause changes in both the colour and hardness of the enamel.
Tooth discolouration has been classified according to the location of the stain, which may be either intrinsic or extrinsic.
Intrinsic discolouration occurs following a change to the structural composition or thickness of the dental hard tissues. The normal colour of teeth is determined by the blue, green and pink tints of the enamel and is reinforced by the yellow through to brown shades of dentine beneath. A number of metabolic diseases and systemic factors are known to affect the developing dentition and cause discolouration as a consequence. Local factors such as injury are also recognised.
This occurs when the outer layer of the tooth (the enamel) is stained as by some drinks or foods or by smoking.
The origin of the stain may be :
Causes of extrinsic discoloration :
These external stains can usually be removed through the use of non-bleaching whitening products such as whitening toothpastes that contain abrasive ingredients which help remove surface stains. A thorough dental cleaning by a dentist or hygienist will also remove most of the extrinsic tooth stains.
It is usually a combination of extrinsic and intrinsic factors. Yellowing teeth are a common symptom of aging. Their mineral structure changes becoming less porous and making teeth to appear darker. The enamel that covers the teeth gets thinner with age, allowing the underlying layer of yellowish dentin to show through. The continuous accumulation of extrinsic stains also contributes to the natural yellowing of the teeth over time.
Internalised discolouration is the incorporation of extrinsic stain within the tooth substance following dental development. It occurs in enamel defects and in the porous surface of exposed dentine. The routes by which pigments may become internalised are: