Luting Cements and Composite Resin Restoratives

Porcelain laminate veneers are used routinely in cosmetic dentistry. The public usually refers to this mode of treatment simply as “veneers.” Their popularity has increased because of television makeover programs, commercials, and magazine advertisements. Porcelain laminate veneers have so increased in their attractiveness that the general public is demanding this type of instant makeover. Further, dental laboratories are competing in marketing their abilities as to how thin they can make their porcelain laminate veneers. Plus, certain manufacturers and laboratories advocate prepless laminate veneer techniques. Porcelain laminate veneers were first introduced by Charles Pincus1 in the 1930s and used to change the appearance of movie actors’ teeth. Unfortunately, denture adhesive was the only means of attaching the veneers to the teeth, and they came off in a short period of time. It was not until after Buonocore2,3 introduced the concept of acid-etching enamel as a means of mechanical retention that composite resin restoratives had retentiveness. By 1982, Simonsen and Calamia4 discovered composite resin’s ability to bond to porcelain if the ceramic was treated with hydrofluoric acid. In 1983, using a refractory model technique, Calamia5 described a technique for fabrication and placement of porcelain laminate veneers. Around the same time, Horn6 described a technique of porcelain laminate veneer fabrication using platinum foil. Since that time there have been numerous articles describing tooth preparation protocols, techniques for fabrication, methods for placement, and the materials to be used for bonding.7-13 Initially, porcelain laminate veneers were placed with restorative composite resin. The same material used for anterior restorations was used to insert veneers because it was the only material available. A significant number of restorations would fracture at the time of placement because the composite was thick and had little flow. In pressing the veneer into place, clinicians sometimes used excessive force, resulting in cracks or complete fractures. Manufacturers recognized these problems and developed entire lines of composite resin luting materials solely for the placement of porcelain laminate veneers and posterior porcelain restorations. The various luting materials differ in color, flowability, film thickness, and volume percentage of filler material. To keep the viscosity at a lower level, both the size and amount of the filler particles are smaller than in restorative composite resins. The physical properties of these materials can lead to post-insertion situations, such as solubility, color change, and flexural strength.14 This article discusses a method and the advantages of thermal conditioning a restorative composite resin or commercial luting cement that can be used for placement of porcelain laminate veneers.