Dental caries is a dynamic, multifactorial disease marked by cycles of demineralization and remineralization. As restorative strategies evolve towards minimally invasive approaches, the role of bioactive materials in promoting natural remineralization becomes increasingly important. Glass ionomer cements (GICs), widely used in restorative dentistry for their chemical adhesion and fluoride release, exhibit bioactivity but have limited mechanical stability. Chitosan, a natural biopolymer with documented antibacterial and chelating properties, has emerged as a promising GIC modifier. This review explores the incorporation of nano-chitosan into GICs to enhance remineralization and structural integrity. Mechanistic pathways of action, such as calcium-phosphate deposition, acid resistance, and matrix reinforcement, are discussed. Overall, the literature suggests that nano-chitosan-modified GICs may offer superior bioactivity and mechanical performance, making them a promising candidate for caries management and tissue-preserving interventions.