Tooth whitening enamel layer may also be gradually thinned or even perforated by the various forms of tooth wear. Teeth may be darkened by a buildup of surface stains (extrinsic staining), which hides the natural tooth color; or the tooth itself may discolor (intrinsic staining). Extrinsic stains can become internalised through enamel defects or cracks or as a result of dentine becoming exposed but most extrinsic stains appear to be deposited on or in the dental pellicle. Causes of extrinsic staining include: Changes in the thickness of the dental hard tissues would result in intrinsic discolouration. There are a few causal factors
Dental material of the tooth, the dentist applies a thin layer (approximately 1/2mm) to the base of the tooth, followed by light curing. Another layer might be applied if the cavity is very large and deep. There are many functions to dental lining materials, some of which are listed below: Calcium Hydroxide Calcium Hydroxide has a relatively low compressive strength and a viscous consistency making them difficult to apply to cavities in thick sections, a common technique used to overcome this issue would be to apply a thin sub-lining of a calcium hydroxide lining and then building up with zinc phosphate prior