CMET renovates conventional glass ionomer cement into a multifunctional pulp-protective restorative material: An in vitro study

It is essential to minimize dental pulp exposure to external stimuli to maintain pulp vitality. Therefore, pulp-protective materials require sealing ability, antibacterial activity, and biocompatibility. Conventional glass ionomer cement (GIC) possesses some of these properties, while calcium 4-methacryloxyethyl trimellitate (CMET) can induce calcification, suggesting potential utility in pulp protection. This study compared conventional GIC, CMET-modified GIC (C-GIC), and Ca-free 4-methacryloxyethyl trimellitate (4-MET)-modified GIC (4M-GIC). 4M-GIC showed decreased compressive strength and shear bond strength, whereas C-GIC exhibited only a reduction in compressive strength without affecting bond strength. Both C-GIC and 4M-GIC released increased levels of Sr2+, Ca2+, Si2+, F−, and Al3+. Notably, C-GIC demonstrated antibacterial activity comparable to that of GIC and 4M-GIC, along with lower cytotoxicity, greater cell proliferation, and increased alkaline phosphatase (ALP) activity and calcium deposition. These findings indicate that CMET incorporation enhances adhesion, ion release, antibacterial activity, and mineralization, indicating that C-GIC as a multifunctional pulp-protective material.