Involvement of matrix metalloproteinases in the onset of dentin mineralization.

In order to study the involvement of matrix metalloproteinases (MMPs) on dentin formation and mineralization, day 18 embryonic mouse tooth germs were cultured for 10 d in the presence or absence of Marimastat, a general MMP inhibitor, or CT(1166), a more selective inhibitor of gelatinases (MMP-2 and MMP-9) and stromelysin-1 (MMP-3). With Marimastat a dose-dependent increase in thickness of the predentin layer and a decreased mineralization of dentin were observed. At the highest concentration of the inhibitor used, enamel formation had ceased.

Immunohistochemical localization of MMP-2, MMP-9, TIMP-1, and TIMP-2 in the forming rat incisor.

Western blots analyses and gelatin zymography established the presence of matrix metalloproteinase (MMP)-2 and -9 in the forming zone of rat incisor. Light microscope immunohistochemistry carried out on undemineralized material provided evidence for strong MMP-2 staining in the secretory ameloblasts, odontoblasts, in the enamel organ, and in the pulp. A weaker staining was observed in predentin and in the outer part of the forming enamel.

TEGDMA-induced toxicity in human fibroblasts is associated with early and drastic glutathione depletion with subsequent production of oxygen reactive species.

Triethylene glycol dimethacrylate (TEGDMA) is a dentin-bonding agent and a major component of various dental restorative biomaterials. TEGDMA monomers are released from dental resins and induce dental pulp inflammation and necrosis. In this study, we have investigated the mechanism of TEGDMA-induced cytotoxicity of fibroblasts.