Generally a veneer is a layer of something over something else. Dental veneers are two types. It can be made of porcelain or dental composite. The best option is porcelain as it is stronger and does not change color over time. The dental composite which is the material we use for filling teeth will change color after couple of years and also will loose the shininess. Most of the time there is no need to grind the teeth at all to be able to do dental veneer. Even if we have to, it will be very minimum and preparation will remain in enamel and won’t reach the dentin underneath.
Dental veneers are very good for fixing the shape of misshaped teeth, like peg laterals or eroded teeth, closing the gap between teeth and to some extend to fix the discoloration in teeth or misalignment of them. Usually veneers are supposed to be very thin and a bit translucent to look natural, so if the teeth are really discolored, it can be difficult to fix the discoloration and achieve the best look as we have to make them less translucent.
The other good use of veneers is make the teeth look whiter. Usually no mater what technique we use, teeth get yellower after some time after whitening with usual whitening techniques. That’s why whitening has to be repeated, roughly, every 6 month. If you prefer to have something done which changed the looks of your teeth for a long time, having thin porcelain veneers is the best to do.