Abstract
Objective Resin composite (RC) layering is increasingly popular in restorative dentistry. However, little is known regarding the color interaction between RC layers. The objective of this article is to review the current literature on color interaction between RC layers and its effect on the overall appearance of the double-layer restoration. Overview A literature review was conducted on theoretical and experimental in vitro studies that tested layered RC systems using different thicknesses. This article discusses specimen design, color measurement methods and devices, parameters defined as outcomes, and RC shades and systems used in the studies of double-layered RC that were reviewed here. Relevant clinical findings and gaps that still exist in the literature were also highlighted. Conclusions Various methods to test layered RC were found in the literature. Each study had a unique design and provided valuable information on color interaction between the enamel and dentin layers that could be applied to clinical use. For more predictable esthetic outcomes, manufacturers could provide tailored recommendations specific for their RC systems, stating the recommended thickness and shade for each layer used in the RC layering technique. Clinical Significance With increased variability in RC shades and manufacturers, it is often difficult to predict the final overall color of restoration with multiple layers. Advancing research on RC layering will help clinicians deliver the best customized restorative treatment tailored to the needs and expectations of their patients. Future research along these lines can enhance the efficiency of chair time and will increase the satisfaction of both clinicians and patients.