A

Studies show that changing the sealer formulation (e.g., epoxy-resin vs zinc-oxide–eugenol or bioceramic) produces large, statistically significant differences in how deeply the material penetrates tubules, whereas varying obturation techniques has little or no effect on penetration depth [Mamootil, 2007, PMID 17764458; Weis, 2004, PMID 15347289].