Clinical Performance of High-Viscosity Glass Hybrid Restorative Systems in Posterior Teeth: A Scoping Review

Background/Objectives: High-viscosity glass hybrid restorative systems (GHRS) were developed to improve the mechanical limitations of conventional glass ionomer cements while preserving their bioactive properties. This scoping review aimed to map and synthesize the currently available evidence regarding the clinical performance of high-viscosity glass hybrid restorative systems in posterior teeth. Methods: A literature search was conducted in PubMed/MEDLINE, Web of Science and Google Scholar using MeSH terms and free-text keywords related to glass hybrid restorative systems and posterior restorations. After screening and eligibility assessment, 39 studies were included in the review. Results: The reviewed studies indicated that GHRS exhibited better wear resistance, higher fracture resistance, improved surface durability, and superior marginal integrity compared with conventional high-viscosity glass ionomer cements. Equia Forte HT (GC Corporation, Tokyo, Japan), combined with nano-filled resin coatings, was the most frequently investigated system and showed favorable short- and medium-term clinical performance in small-to-moderate posterior restorations. Discussion: Glass-hybrid restorative systems have demonstrated considerable potential in minimally invasive dentistry, atraumatic restorative treatment, and pediatric restorative applications, particularly in patients with increased caries susceptibility. Their sustained fluoride release, chemical adhesion to dental tissues, and improved moisture tolerance may contribute to favorable clinical outcomes in challenging operative conditions. Conclusions: Within the limitations of the available evidence, high-viscosity glass-hybrid restorative systems may represent a promising restorative option for selected posterior restorations. Nevertheless, the available evidence remains heterogeneous, and further high-quality long-term randomized controlled trials are required to confirm their clinical performance and indications.