1.in Vitro Effet Of Decellularized Matrix On Proliferation And Differentiation Of Periodontal Ligament Stem Cells 2.Efficacy Of Apically Repositioned Flap In Combination Of Xeogenic Callagen Matrix In Augmenting Keratinized Mucosa Around Dental Implants

Objective:The aim of this study was to prepare decellularized matrix(DCM)derived from human periodontal ligament cells(PDLCs),dental pulp cells(DPCs)and gingival fibroblasts(GFs).Moreover,the effect of these decellularized matrix on the proliferation and differentiation of human periodontal ligament stem cells(PDLSCs)was evaluated.Methods:Cell sheets of PDLCs,DPCs and GFs were decellularized using surfactant combined with DNase.Allogenic PDLSCs were seeded on DCM from PDLCs,DPCs and GFs.The proliferative capacity of PDLSCs was evaluated by Pico Green assay kit.The expression of alkaline phosphatase(ALP),runt related transcription factor 2(RUNX2),osteocalcin(OCN),cementum protein 1(CEMP1),collagen type I alpha 1 chain(COL1A1)and periostin(POSTN)were detected by quantitative real time polymerase chain reaction(q RT-PCR).Results:PDLC-DCM,DPC-DCM and GF-DCM prepared by surfactant combined with DNase had similarly integrated networks of extracellular matrix and significantly reduced DNA content.Compared with control group in which PDLSCs were directly seeded in culture plates,PDLC-DCM,DPC-DCM and GF-DCM promoted the proliferation of PDLSCs.The results of q RT-PCR showed that on day 7 and 14,higher expression levels of ALP and RUNX2 were found in PDLSCs on PDLC-DCM,DPC-DCM and GF-DCM compared to those in control group(p<0.05).Additionally,the expression level of COL1A1 and POSTN in PDLC-DCM group was significantly higher than control group(p<0.05).Conclusion:Surfactant combined with DNase effectively removed cells and preserved extracellular matrix integrity.PDLC-DCM,DPC-DCM and GF-DCM can enhance the proliferation of PDLSCs.PDLC-DCM may facilitate osteogenic differentiation and periodontal ligament differentiation of PDLSCs.DPC-DCM and GF-DCM could promote the osteogenic differentiation to a certain extent.Objective:The aim of this study was to evaluate the efficacy of an apically repositioned flap(ARF)combined with xenogenic collagen matrix(XCM)in augmenting keratinized mucosa around dental implants.Methods:The patients who underwent ARF combined with XCM were included.Clinical examinations were performed before surgery and at 2 and 6 months postoperatively,which included width of keratinized mucosa(KMW),thickness of keratinized mucosa(KMT),gingival index(GI)and probing depth(PD).Postoperative pain was evaluated one week after surgery and patients’ satisfaction was recorded at 2 and 6 months following surgery in visual analogue scale(VAS).Results:Five patients were included in this study.At 6 months after surgery,KMW around dental implants increased 2 mm with no significant change in KMT,GI or PD.The score of postoperative pain varied with each individual,ranging from 0 to 7.However,patients’ satisfaction in VAS was high(≥8)in all patients.Conclusion:ARF in combination with XCM could effectively increase KMW around dental implants and maintain short-term stability.In addition,the color and texture of regenerative mucosa in the surgical sites were similar with those of the adjacent tissue.