BDKRB1 and periodontitis: Although a previous study by Goncalves-Zillo et al. found that Bdkrb1-/- mice with ligatured-induced periodontitis had increased bone loss in the furcation area [28], there is no significant difference in bone resorption found between SM oil-treated and oil-free samples in the root furcation area (Figure 2a) in this study.