Aesthetic dental veneering materials

They are numerous clinical indications for the use of aesthetic tooth coverings including heavily stained teeth, hypoplasia and other developmental disorders, and traumatic injuries. The acid etch technique provides a means of attaching composite resins and preformed acrylic veneers to enamel to cope with these problems. Four basic techniques are in use: (a) freehand placement of cold-cured or light-cured acrylic resins, (b) use of a crown form with technique (a), (c) commercially performed acrylic laminated bonded to the tooth with cold- or light-cured resins and (d) individually made preformed laminates bonded as in (c). A meticulous acid etch technique is necessary, including the use of 35 per cent phosphoric acid for up to 120 seconds on difficult surfaces such as primary or highly fluorosed enamel. Special care is needed at the gingival margin, for poor bonding is obtained by dentin/cementum. Successful results can be obtained with all four techniques when experience has been gained. The quickest and most flexible technique is (a), whereas (d) is capable of the best contour, adaptation and aesthetics. However, in (d) laboratory procedures add to costs. The most convenient resins for freehand placement and bonding of veneers are the light-cured (composite) resins. Cold-cure resins have short working time and are best used with an unfilled resin primer. Clinical studies indicate that a life of at least 3-4 years for enamel veneers can be expected if incisal coverage is avoided. Research is in progress to improve durability. These restorations should be regarded at present at medium-term treatments and should be so presented to the patient. Even with current materials, a dramatic improvement in appearance can effect a major transformation in the self-esteem of the patient.