Materials used between root canal orifices and coronal restorations: a scoping review

This scoping review aims to map and synthesize the existing literature on materials used between root canal orifices and coronal restorations following pulp therapy. Specifically, it focuses on materials described as intracoronal spacers or intra-orifice barriers, exploring how they have been defined, indicated, and evaluated across different clinical and experimental contexts. The review will be conducted in accordance with the PRISMA-ScR guidelines. Eligible studies will include in vitro, ex vivo, in vivo, and clinical investigations assessing materials placed at the entrance of the root canal system or on the pulpal floor to provide coronal sealing or protection after endodontic procedures. Data will be extracted regarding study design, type of dentition and tooth investigated, materials used, thickness and placement protocols, methods employed to assess sealing ability and coronal leakage, association with coronal restorations, and reported limitations. By organizing and critically mapping the available evidence, this review is expected to identify conceptual ambiguities, methodological heterogeneity, and gaps in the literature, particularly concerning the primary dentition. The findings may support researchers in designing more standardized experimental and clinical studies and assist clinicians and educators in interpreting current evidence regarding the role of intracoronal spacers and intra-orifice barriers in pulp therapy.