Oral conditions change over time. A healthy tooth at present may be lost in years to come. Decay, periodontal disease, bruxism (tooth grinding), toothbrush erosion, oral hygiene, accidents, diet and many other factors influence the life of a tooth. A veneer is a thin layer, often as thin as 0.4mm that covers the front of a tooth. Does this layer extend the life of a tooth or protect it from the harsh oral environment? No. The tooth material that is replaced by a veneer is as hard as enamel, but it will wear down like a tooth, it can chip or even crack like a tooth. A veneer is non-porous and therefore will not decay, but the areas around it are still subject to the forces of nature and therefore decay, periodontal disease etc, are a reality. Here is an example: A veneer at present may look great, but in ten or fifteen years time, it may not extend from the gum as the gum has receded. It may be worn down with the other teeth and appear short. The tooth may be decayed below the gum or the veneer is chipped. Veneers may or may not need to be replaced down the line. It is important that patients are aware of these facts and should not expect life-guarantee for veneers. Our workmanship for “lava” crowns is guaranteed for five years and our veneers for three. This is also subject to the conditions of maintanance and any other dental requirements prescribed by the dentist. Thanks for the good question.