Fig. 4

Statistical analyses of correlation of relative amount of regenerated pulp with the bacterial number and lesion volume before root canal treatment, and with reduced rates of lesion volume in the successful root canals. A No correlation of relative amount of regenerated pulp with bacterial number before root canal treatment (model A: R =  − 0.257, model B: R = 0.243). B No correlation of relative amount of regenerated pulp with the lesion volume before root canal treatment (model A: R =  − 0.265, model B: R = 0.090). C Correlation of relative amount of regenerated pulp with reduced rates of lesion volume at cell transplantation compared with that before root canal treatment (model A: R = 0.314, model B: R = 0.760). D Correlation of relative amount of regenerated pulp with reduced rates of lesion volume at extraction compared with that at before root canal treatment (model A: R = 0.445, model B: R = 0.372). E No correlation of relative amount of regenerated pulp with reduced rates of lesion volume at extraction compared with that at cell transplantation (model A: R = 0.187, model B: R =  − 0.188). Model A: round dashed line, model B: square solid line. Eight root canals in model A and 10 root canals in model B with successful pulp regeneration