The expression of MMP-9 and transforming growth factor beta (TGF-β1) was previously evaluated in samples of periapical lesions and correlated with the intensity of the inflammatory infiltrate and the thickness of the epithelial lining, showing that the extracellular matrix remodeling process is dependent on MMP-9 appears to be similar for periapical granulomas and root cysts .24 This evidence concerns the gene TGFB1 and periapical granuloma.