Use Of Platelet-rich Fibrin Membrane In The Treatment Of Expeimental Miller Class ? Gingival Recession In Beagles

Objective To construct a Miller class III gingival recession animal model,to observe the therapeutic effect of platelet-rich fibrin(PRF)on Miller III-degree gingival recession.Methods Two adult male beagle dogs were selected,and four animal teeth were selected to establish an experimental Miller class III gingival recession.General anesthesia was performed with 3% sodium pentobarbital,and local anesthesia was performed.After the flap was flapped,5 mm alveolar bone in buccal and 2mm alveolar bone in adjacent surface were alveolar bone,5mm gingival tissue was removed and the wound was sutured.Assessment whether the model is successful by meansure the vertical gingival retraction(VGR),horizontal retraction(HGR),keratinized tissue width(KTW),gingival tissue thickness(GTT),and probing depth(PD)at 1,2,4,6,and 8weeks after modeling.Two months after the completion of the modeling,the right and left sides of the same animal were compared and grouped for surgery that the coronally advanced flap combine with the subepithelial connective tissue graft(CAF+SCTG)and the coronally advanced flap combine with the platelet-rich fibrin membrane(CAF+PRF),opened half thick flaps after anesthesia,gingival nipples were de-epithelialized and root surface were mechanically cleaned by 17% EDTA for 5 min.Then,cut off SCTG from palate and prepare PRF,implanting the SCTG and PRF separately,crown-reduced the gingival flaps and suture the wounds.By measuring the clinical indicators that VGR,HGR,KTW,GTT,PD,and root surface coverage(RC)at1,2,4,6,8 and 12 weeks after surgery,the therapeutic effect of CAF+PRF for experimental beagles Miller class III gingival recession were evaluated.Results After observing the clinical indicators,the method that construct the animal model of Miller class III gingival recession were proved successfully,which can remain stable after wound healing,and the keratinized tissue width(KTW)and gingival tissue width(GTT)did not change significantly after tissue healing compared to pre-modelling.Both CAF+SCTG and CAF+PRF were proved that were achieve therapeutic effects to some extent for Miller class III gingival recession.The VGR and HGR were both decreased,the KTW was increased,but the amplitude was smaller,and the GTT was also modest increased.The difference of the root surface coverage ratios was significant between the two groups.Comparison between the two groups showed that the CAF+SCTG group was superior to the CAF+PRF group in obtaining root surface coverage,and the difference was statistically significant,while the growth of KTW and GTT was not significantly different.PRF was superior to SCTG in fighting tissue inflammation and less healing tissue edema.Conclusion In this study,the method of coronally-advanced flap(CAF)+ platelet-rich fibrin(PRF)that in the treatment of experimental Miller class III gingival recession in beagle dogs were proved to be effective that resulted in a certain amount of root coverage,and plays an important role in promoting wound healing by fight against tissue inflammation.It laid a foundation for the clinical application of PRF in treating gingival recession...