title: [The study of cytotoxicity of different intracanal medications and cell rehabilitation on human periodontal ligament fibroblasts].
abstract: OBJECTIVE
  To determine the cytotoxicity and reversibility of cytotoxicity of 5 intracanal medications in various concentrations with human periodontal ligament fibroblasts (HPLFs), with the aim to provide a comprehensive reliable scientific evidence for making a good choice of these intracanal medications in clinical practice.
  
  
  METHODS
  The experimental medications included formocresol (FC), camphorated paramonochlorophenol(CP), metronidazole, calcium hydroxide and traditional Chinese medicine. HPLFs were obtained from healthy premolars extracted for orthodontic reasons. All samples were placed into DMEM, cultured and harvested from the fourth to eighth passages. MTT, alkalinephosphatase (ALP)activity determination and transmission electron microscope (TEM) were used in this study. The data was analyzed by SPSS11.5 software. Student's t test, analysis of variance was used for the statistical analysis.
  
  
  RESULTS
  FC, CP had cytotoxicity and inhibited the growth and ALP activity of HPLFs significantly (P<0.01 and P<0.05). The cytotoxicity of FC was at 3- 4 grade, with cell rehabilitation rate less than 30%. The cytotoxicity of CP was at 1 to 3 grade, with cell rehabilitation rate less than 30%. Metronidazole lightly inhibited the proliferation and ALP activity of HPLFs, its cytotoxicity was at 1 grade, with rehabilitation rate from 32% to 85%. Calcium hydroxide and Chinese medicine didn't inhibit the proliferation and ALP activity of HPLFs significantly (P>0.05). Their cytotoxicity was at 0 to 1 grade with cell rehabilitation rate more than 90%. TEM study showed that severe morphologic alteration of HPLFs induced by FC, CP, whereas the cells in Chinese medicine and calcium hydroxide had little alteration on their morphology. Metronidazole induced minor morphologic alteration of HPLFs.
  
  
  CONCLUSIONS
  Calcium hydroxide, traditional Chinese medicine have no cytotoxicity while FC and CP lead to severe cytotoxicity, the cytotoxicity is irreversible. Therefore the clinical application of FC and CP is no longer recommended. Traditional Chinese medicine or calcium hydroxide can be taken as ideal intracanal medications.
authors.affiliation: Department of Dentistry, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, China. XSJ@citiz.net
authors.forename: Xiao-li
authors.initials: XL
authors.lastname: Wang
authors.forename: Meng
authors.initials: M
authors.lastname: Song
authors.forename: Jia-ning
authors.initials: JN
authors.lastname: Lou
authors.forename: Xiao-yong
authors.initials: XY
authors.lastname: Niu
mesh_terms: D002126:Calcium Hydroxide / Q000494:pharmacology*; D002478:Cells, Cultured; D005347:Fibroblasts; D006801:Humans; D008516:Medicine, Chinese Traditional; D010513:Periodontal Ligament
chemical_list: D002126:Calcium Hydroxide