Marginal integrity in conservative and endodontic dentistry is vital for the success and longevity of dental restorations, ensuring a precise fit between restorative materials and the natural tooth structure to prevent secondary caries, bacterial infiltration, and restoration failure. In conservative dentistry, this involves achieving tight margins in direct and indirect restorations through careful material selection, meticulous application techniques, and thorough tooth preparation. In endodontics, maintaining marginal integrity is crucial for effectively sealing the root canal system, utilizing materials like gutta-percha and sealers that adhere closely to canal walls. Advances in evaluation methods, such as dye penetration tests and scanning electron microscopy, alongside the development of superior materials and adhesives, aim to enhance marginal adaptation and durability, underscoring the importance of precision and innovation in both fields to improve clinical outcomes andpatient satisfaction.