Fig 2: Comparison of gene expression between PDL tissue and PDLFs by quantitative PCR in four PDL marker genes (OPN, ASPN, POSTN, and SPARC). PCR, polymerase chain reaction; PDL, periodontal ligament; PDLF, PDL fibroblast

Fig 3: The summary of gene profiling of collagens, noncollagenous proteins, and proteoglycans in PDL tissue. (a) The ratio of collagens in PDL tissue mainly were collagen type I (72%) and III (19%), followed by type VI (4%), V (2%), XII (1%), and others. (b) Ratio of noncollagenous proteins in PDL tissue mainly were POSTN (38%) and SPARC (35%). (c) Ratio of proteoglycan in PDL tissue mainly were ASPN (30%), LUM (26%), DCN (15%), and OMD (11%). ASPN, asporin; DCN, decorin; LUM, lumican; OMD, osteomodulin; PDL, periodontal ligament; POSTN, periostin