Fig. 1.

Ligature or Ligature/P.g. LPS induced periodontitis in ApoE^−/− mice. a Timeline of the study. b Palatal tissues including the ligatured upper second maxillary molars at the time of mice sacrifice. Black arrows indicate 6-0 silk suture used for ligature placement. Swelling of palates was noticed. c Two-dimensional or three-dimensional μCT images of maxillae in the control mice (n = 5), mice receiving ligature (n = 5), or ligature/P.g. LPS (n = 5). Scale bar: 1 mm. d Measurement of alveolar bone loss: Distance (mm) from the CEJ to ABC of the second molars. e Hematoxylin and Eosin (H&E) staining of the maxillary second molar. Scale bar: 50 μm. f TRAP staining for the presence of osteoclasts (pink color; black star) from periodontal tissue. Bone resorption was confirmed by the presence of osteoclasts. TRAP-positive osteoclasts number per area was counted under a blinded manner by two people. Scale bar: 50 μm. Abbreviations: D, dentin; SF, silk fibroin; AB, alveolar bone; JE, junctional epithelium; PDL, periodontal ligament. ***P < 0.001 in one-way ANOVA. Results represent the means ± SD performed in triplicate