Two-year clinical evaluation of composite resin restorations in posterior teeth

Profissionais Envolvidos no Caso Clínico

Vieira, L.C.C.
Baratieri, L.N.
Lopes, G.C.
Portela, R.
Andrade, C.A.
Composite Resin Restorations in Posterior Teeth, JBD, Curitiba

Case Clincial

The improvement achieved in the physical properties of restorative composite resins, combined with the development of effective dentin adhesive systems, has made their use routine in daily clinical practice. It is undeniable that the most used and most recommended material for posterior teeth is silver amalgam, which cannot be disregarded. However, the growing interest demonstrated by patients in receiving restorations as imperceptible as possible, even in posterior teeth (Christensen, 1995), and the development of techniques and materials that facilitate such restorative procedures (Baratieri et al., 1998; Dietschi & Spreafico, 1997) have contributed to the popularization of aesthetic restorations in posterior teeth (Leinfelder, 1999). Adhesion to enamel has become a routine and a reality in restorative dentistry. Pre-conditioning with phosphoric acid can transform the enamel surface, making it more receptive to adhesion (Buonocore, 1955). In this way, resin extensions would form in the micro-porosities of the conditioned enamel, providing a strong and durable bond. The ability of dentists to provide enamel adhesion has changed the concepts of cavity preparation, caries prevention, and aesthetics (Perdigão & Lopes, 1999). In dentin, the trend in the technological development of adhesive systems also seems to involve total acid conditioning (Swift Jr. et al., 1995). With the removal of the smear layer, the hydrophilic components of the latest adhesive systems displace the moisture from the conditioned dentin, preparing the substrate for the application of the fluid resin, which will polymerize within the tubules and the demineralized intertubular and peritubular dentin, forming the hybrid layer (Kanca, 1992). This hybrid layer seems to be essential for good resin adhesion to dentin (Nakabayashi, 1992; Nakabayashi et al., 1982). The total conditioning technique is certainly one of the most popular strategies for adhering restorative materials to dentin and enamel. Despite the extensive use of composite resins in posterior teeth, medium- and long-term evaluations of these restorations are scarce (Bryant et al., 1994; Pallesen & Qvist, 1995; Collins et al., 1998). To aid the clinical evaluation of direct composite resin restorations, using the variety of available systems, it is necessary to rely on in vitro studies of these materials. Although in vitro studies are an important source of data for evaluating the performance of materials before they are clinically applied, there should always be a direct correlation between the in vitro and in vivo performance of an adhesive restorative system. The three-dimensional configuration of the cavity preparation is different from the smooth surfaces commonly used to test adhesive materials in the laboratory. Additionally, the adhesive interface is subjected to a variety of different stresses and more challenging situations over time when applied in vivo (Baratieri & Ritter, 2001). The present study aimed to clinically evaluate two restorative systems for posterior teeth (Scotchbond Multi-Purpose/Z-100, 3M and Magic Adhesive/Fill Magic, Vigodent) when applied in restorations.