[1] Chongqing Med Univ, Stomatol Hosp, Dept Conservat Dent & Endodont, 426 Song Shi Bei Lu, Chongqing 401147, Peoples R China
[2] Chongqing Key Lab Oral Dis & Biomed Sci, Chongqing 401147, Peoples R China
[3] Chongqing Municipal Key Lab Oral Biomed Engn High, Chongqing 401147, Peoples R China
[4] Southwest Med Univ, Affiliated Stomatol Hosp, Dept Endodont, Luzhou 646000, Sichuan, Peoples R China