The authors are grateful for the kind cooperation of all the study participants.They also sincerely thank Cathy Nabet and Stephanie Brayer for their valuable assistance with ethical committee procedures.The authors would also like to thank Adrian Minty,a native English speaker,for proofreading and improving the language of the manuscript.We acknowledge Dr Jeffrey Christensen and Pr Mikio Shoji from Nagasaki University Graduate school of Biomedical Sciences for their valuable assistance with the use of Porphyromonas gingivalis strain whose LPS is devoid of its O-saccharide part(wzy:Em PGN_1242).We acknowledge Christele Segura and the《I2MC-Plateau Histologie Imagerie》(Genotoul-TRI),member of the national infrastructure France-BioImaging supported by the French National Research Agency(ANR-24-INBS-0005 FBI BIOGEN). This study was supported by the Paul Calas Award from the French Society of Endodontics(SFE).The funding body had no role in the study design,data collection,analysis,interpretation,or manuscript writing.Except that,we have not received any funding,grants,or personal benefits from any organization that could affect the objectivity of this study. （wzy:Em PGN_1242）