They can be used to cover staining, repair chips/breaks, change colours, smile makeovers and to close spaces.
Porcelain is the most similar of all materials to natural enamel and hence, when done well, it can look more natural, attractive and resists stain better than other materials including composite.
However, they require space to be made on the tooth to fit them and traditional porcelain veneer techniques involve drilling away natural tooth to create this space. If this is not done carefully it increases the risks to the long term health of the teeth decreases the lifespan of the veneers.
To minimise these risks it is recommended to straighten the teeth first and use state of the art guided techniques to make very thin additive veneers and minimise the drilling needed, in some cases eliminating it. This means the veneers can be bonded mainly to the enamel which results in longer lifespans.
Porcelain veneers last 10-15 years on average but they may last shorter or longer than this depending on care and repair is not as easy as it is with composite.