Preheated Composite for Prosthetic Cementation to Enamel and Dentin: A Scoping Review

Background and Objectives: Preheated composite resins have been proposed as an alternative to conventional luting agents due to their improved resistance, color stability, and adaptation. This review aims to critically evaluate the current literature on the use of preheated composites as luting agents exclusively on dentin and enamel, focusing on their mechanical behavior, optical properties, and biological effects, in order to determine whether they provide superior clinical outcomes compared with conventional resin cements. Materials and Methods: A comprehensive literature search from 2015 to 2025 was conducted in accordance with PRISMA-ScR guidelines. Eligible studies included in vitro investigations comparing the preheated composite with other luting agents performed on human, bovine, analog dentin or enamel substrates. Studies meeting these criteria were screened, evaluated, and synthesized. Results: Fifteen studies met the inclusion criteria: nine focused on the mechanical performance, and the remaining six studies examined additional properties such as color stability, pulpal temperature changes during preheating, film thickness characteristics, and the influence on marginal discrepancy. Conclusions: Preheated composite resins offer improved mechanical properties, marginal adaptation, and fracture resistance compared with conventional luting agents. However, their performance is highly technique-sensitive, and clinical outcomes depend on operator skill, restoration thickness, and material selection. Preheating generally does not compromise color stability, but it can elevate pulpal temperature, particularly when residual dentin is thin. Overall, preheated composites have potential clinical advantages, provided that careful handling and appropriate application are ensured.