Dental fluorosis (also termed mottled enamel) is an extremely common disorder, characterized by internationalization of tooth enamel caused by ingestion of excessive fluoride during enamel formation.  In the "mild" form of the disease, these mottled patches can involve up to half of the surface area of the teeth. 

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 requiring more than single visit to the dental clinic. In case of 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, hence making the crown looking natural. While, the metal free crowns are computer aided designed 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.