Veneer
In dentistry, a veneer is a layer of material placed over a tooth, either to improve the aesthetics of a tooth or to protect the tooth’s surface from damage. There are two main types of material used to fabricate a veneer: composite and dental porcelain. A composite veneer may be directly placed (built-up in the mouth), or indirectly fabricated by a dental technician in a dental lab, and later bonded to the tooth, typically using a resin cement such as Panavia. In contrast, a porcelain veneer may only be indirectly fabricated. Full veneer crown is described as “A restoration that covers all the coronal tooth surfaces (Mesial, Distal, Facial, Lingual and Occlusal)”. Laminate veneer, on the other hand, is a thin layer that covers only the surface of the tooth and generally used for aesthetic proposes .
Veneers were invented by California dentist Charles Pincus in 1928 to be used for a film shoot for temporarily changing the appearance of actors’ teeth. Later, in 1937 he fabricated acrylic veneers to be retained by denture adhesive, which were only cemented temporarily because there was very little adhesion. The introduction of etching in 1959 by Dr. Michael Buonocore aimed to follow a line of investigation of bonding porcelain veneers to etched enamel. Research in 1982 by Simonsen and Calamia revealed that porcelain could be etched with hydrofluoric acid , and bond strengths could be achieved between composite resins and porcelain that were predicted to be able to hold porcelain veneers on to the surface of a tooth permanently . This was confirmed by Calamia in an article describing a technique for fabrication , and placement of Etched Bonded Porcelain Veneers using a refractory model technique and Horn describing a platinum foil technique for veneer fabrication. Additional articles have proven the long-term reliability of this technique .
Today, with improved cements and bonding agents, they typically last 10–30 years . They may have to be replaced in this time due to cracking , leaking , chipping , discoloration , decay , shrinkage of the gum line and damage from injury or tooth grinding.