Fig. 1

Circadian disruption by shift work simulation aggravates experimental periodontitis in mice. a The intensity and diurnal oscillation of physical activity in mice under normal or simulated shift work conditions measured by voluntary running wheel assay. b Relative mRNA expressions of indicated circadian clock genes in gingiva of mice under normal or simulated shift work conditions (n = 3). c The representative sagittal tridimensional and bidimensional views of the maxillary molars scanned by micro-CT (scale bar: 500 μm). d Quantification of the BMD, BV/TV, and the distance from the CEJ to the ABC in indicated groups (n = 7). e H&E staining of paraffin-embedded sections (scale bar: 500 μm; 75 μm). Data are represented as the mean ± SD. ns, no significance; *P < 0.05; **P < 0.01; ***P < 0.001. Abbreviations: ZT zeitgeber time, NN mice under normal light-dark cycles without ligature, NL mice under normal light-dark cycles with ligature, DN mice under disturbed light-dark cycles without ligature, DL mice under disturbed light-dark cycles with ligature, BMD bone mineral density, BV/TV bone volume fraction, CEJ cement-enamel junction, ABC alveolar bone crest, H&E hematoxylin and eosin