Intrinsic staining of the teeth, unlike extrinsic stains, can’t be treated with bleaching. Various causes of such discoloration can have detrimental effects on normal tooth structure formation, like trauma, excess fluoride intake, taking medication (esp. tetracycline), vitamin deficiency or any hereditary disorder (e.g. amelogenesisimperfecta, dentinogenesis imperfection, and other developmental disorders).
Fluorosis of teeth occurs due to excessive intake of fluoride during the process when tooth is getting calcified. Depending on severity, it affects both shape and colour of the teeth, hence compromising the cosmetics. Trauma to the developing tooth bud can cause hypoplasticdefect, which appears white in color. Tetracycline stains and developmental disorders also produce characteristic staining and later also cause changes in shape of teeth making them more prone to dental caries. Treatment required for any of such condition depends on the severity of the discoloration and need to restore the form of the tooth. In normal cases, microabrasion and macroabrasion do not provide satisfactory results in badly discolored teeth, which make patients disgruntled.
Before starting the fabrication of crowns and veneers, the teeth requiring the treatment are prepared. Slight tooth structure is removed from all around the tooth for crown fabrication. In case of veneer, only the visible outer surface (labial /buccal) is prepared for treatment.
Both kind of crowns and porcelain veneers are made and processed in the dental laboratories using replica model of the patient’s prepared tooth/teeth. Hence it requires more than single visit to the dental clinic. For PFM crowns, the base of the crown is formed by an inert alloy material, over which a layer of porcelain is placed and fused to underlying metal alloy at high temperature, thereby making the crown look natural. The metal free crowns have computer-aided design and machined in the laboratory out of the porcelain block, using the duplicate model of the tooth. After the crowns are obtained from the laboratory, the can be properly fitted on the patients prepared teeth using bonding and cementation. Porcelain veneers are also prepared in the same way as pure porcelain crowns, just that they cover lesser surface area of teeth. However, composite veneers can be done in single sitting of the treatment as they can be directly fabricated and bonded over the prepared teeth surfaces in dental office, then skipping the lab work.