Root Canal Sealing and Filling Materials Biofill powder and resin are mixed to produce a root canal filling material of excellent sealing capacity. As a result of its close adaptation to the root canal walls and its very small contraction during setting, Biofill allows tightly sealing root canal obturation of excellent tissue compatibility. Biofill complies with the requirements of ISO 6876 : 1986 (E) for dental root canal filling materials.