ABSTRACT
Objective@#To study the effects of platelet-rich fibrin extract (PRFe) and platelet-derived growth factor (PDGF) released from PRFe on the proliferation of human gingival fibroblasts (HGFs) and to provide an experimental basis for its application in promoting gingival soft tissue increment.@*Methods@#Platelet-rich fibrin (PRF) was transformed into PRFe by tissue culture. The three-dimensional structure of PRF was observed by electron microscopy, and the content of PDGF in PRF was quantitatively determined by ELISA. The ratios of PRFe examined were 2.5% PRFe, 5% PRFe, 7.5% PRFe, 10% PRFe, 12.5% PRFe and 15% PRFe. Gingival fibrosis was detected by the CCK-8 method. After determining the optimal concentration of PRFe, flow cytometry was used to detect the effect of PRFe on the proliferation cycle of human gingival fibroblasts, and the effect of PDGF on the proliferative activity of gingival fibroblasts was observed by neutralizing the release of PDGF.@*Results @# PRF is a three-dimensional reticular structure that contains a large number of growth factors. PDGF release peaked on the 7th day. The proliferative activity of HGFs cultured with different concentrations of PRFe was concentration-dependent, but the effect was optimal at 5% PRFe (P < 0.05). There were no significant differences in the effect of subsequent concentration increases on the proliferation of HGFs (P > 0.05). The flow cytometry results showed that 5% PRFe could significantly stimulate the S-phase division and proliferation of gingival fibroblasts, while the PDGF neutralization test showed that the proliferation of gingival fibroblasts was significantly inhibited by the neutralization of PDGF.@*Conclusion@#Overall 5% PRFe had the best effect on promoting gingival fibroblast proliferation in vitro. PDGF released from PRF plays an important role in promoting the proliferation of gingival fibroblasts.
ABSTRACT
Objective @#To construct a Miller class Ⅲ gingival recession animal model and to lay the foundation for exploring the treatment of Miller class Ⅲ gingival recession. @*Methods@#Two adult male beagle dogs were selected, and four teeth from each beagle dog were selected to establish an experimental Miller class Ⅲ gingival recession model. The root surface was revealed by removing the soft and hard tissues of the buccal side. The success of the model was determined by measuring the vertical gingival retraction (VGR), horizontal retraction (HGR), keratosis tissue width (KTW), gingival tissue thickness (GTT), and probing depth (PD) at 1, 2, 4, 6, and 8 weeks after modeling. @*Results@#After observing the clinical indexes, the PDs before and after the modeling were all smaller than 3 mm and no deep-period pockets were formed. The VGR before modeling was 0 mm, and the VGR range after modeling was 5-6.38 mm. A comparison of the before and after modeling results showed that this difference was statistically significant (P < 0.05). The postoperative VGR results were grouped according to timepoint. A comparison between the two groups showed that the differences at 2, 4, 6 and 8 weeks postoperatively were not statistically significant (P > 0.05). The HGR before the modeling was 0 mm, and the HGR fluctuated around 10.5 mm after the modeling, and this difference was statistically significant (P < 0.05). The HGR results were grouped by timepoint after surgery, and a one-way analysis of showed that the differences between the two groups were not statistically significant (P > 0.05). The KTW range before modeling was 6~9 mm, and it fluctuated around 2 mm after modeling, and this difference was statistically significant (P < 0.05). The KTW results were grouped by timepoint after surgery, and they indicated that significant differences did not occur between the groups postoperatively (P > 0.05). The pre-modeling GTT was 1.5 mm, and the GTT range after modeling was 1.5-2 mm. The preoperative and postoperative GTT results were grouped by timepoint, and the results showed that significant differences did not occur between 1 week and 2 weeks after surgery (P = 0.123), although a statistically significant difference was observed at 1 week postoperatively between this group and the other groups (P < 0.05).@*Conclusion@#The method used in this experiment can successfully build a Miller class III gingival recession animal model, and the model remains stable after wound healing.