This review paper describes the various applications of 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane (4-META/MMA-TBB) and reviews research studies on the treatment of infected root canals using 4-META/MMA-TBB resin. 4-META/MMA-TBB resin exhibits good biocompatibility, polymerisation, and adhesiveness to dentine. As a result, it has improved the previously low success rates of root-end sealing, root canal filling, and perforation sealing in difficult cases. Root-end sealing of resected surfaces using 4-META/MMA-TBB during apicoectomy and intentional replantation prevents leakage from root canal and root resorption. 4-META/MMA-TBB can offer sealing for root canals with opened root apex in which pressure could not be applied during root canal filling. In this paper we will discuss clinical cases related to the application of this resin and the benefits of 4-META/MMA-TBB resin.