Selection defines design.

The era of "extension for prevention" used restorative materials and cavity preparation designs in an attempt to arrest the caries process. In the new era of "prevention to eliminate extension," many of the old limitations are no longer applicable because of advances in research and technology. The advances in restorative materials and adhesive technology require the use of an adhesive design concept when considering restorative material selection, preparation designs, and adhesive protocol and placement procedures and techniques. This adhesive design concept has been instrumental in the paradigm shift from the principles of extension for prevention to an ultraconservative principle of prevention to eliminate extension. From the early onset of the disease to initial placement of the restoration, this modern philosophy has three clinical objectives: prevention, preservation, and conservation. The clinician should strive to preserve the maximum integrity of the natural dentition by preventing the placement of the initial restoration, preserving and conserving tooth structure during the preparation of restoration, and conserving the tooth and restoration by increasing the longevity of the restoration between replacements. This article describes an incremental layering technique that uses a conservative restorative adhesive design concept (adhesive preparation design and protocol) for preparing, restoring, and finishing a Class IV restoration, and it demonstrates how the selection of a small-particle hybrid composite influences the preparation design. CLINICAL SIGNIFICANCE Selection of improved restorative materials that simulate the physical properties and other characteristics of natural teeth in combination with an adhesive design concept and preoperative considerations during the diagnostic and treatment planning phases of the restorative procedures provide the framework that ensures the optimal development of an esthetic restoration while preserving, conserving, and reinforcing the tooth-restoration complex.