title: Effect of umbilical cord mesenchymal stem cell in peri-implant bone defect after immediate implant: an experiment study in beagle dogs.
abstract: BACKGROUND
  For the sake of reducing post extraction resorption, getting optimal positioning of the implant and shortening treatment time, immediate implant placement following tooth extraction has been proposed as a treatment option. However, the large bone defect peri-implant has a negative influence on the process of bone healing. In this study, umbilical cord mesenchymal stem cells (UCMSCs) were transplanted into the bone defect peri-implant inbeagle dogs and the effect of UCMSCs on bone regeneration in peri-implant were assessed.
  
  
  METHODS
  The mandibular second, third and fourth premolars of 8 beagle dogs were extracted bilaterally. The defects in one side were filled with platelet-rich fibrin (PRF) and then UCMSCs were injected into the defect area, while the defects in the other side were filled with PRF only as control group. The titanium implant was placed into the distal root socket of each extracted tooth. The animals were sacrificed at week 2, 4 and 8 post operative. The bone defects adjacent to the implant which are 4 mm in height, 4 mm in the mesio-distal direction and 3.5 mm in the bucco-lingual direction were made after immediate implant. Histomorphometric analysis was performed using methylene blue-fuchsin acid staining and hematoxylin and eosin (HE) staining to evaluate bone regeneration.
  
  
  RESULTS
  The direct bone-to-implant contact (BIC) in the experiment after 4 and 8 weeks was 56.47±1.18% and 76.23±2.08%; and in the control group was40.79±0.65% and 61.17±2.79%, respectively. The percentage of newly formed bone after 2, 4 and 8 weeks was 17.60±1.5%, 49.82±4.02% and 67.16±2.1% in experiment group; and in control group 14.30±1.25%, 37.04±2.29% and 58.83±3.36%, respectively. These results represented significant differences statistically.
  
  
  CONCLUSIONS
  Intra-bone marrow injection of UCMSCs can promote new bone formation. UCMSCs can be used to as excellent seed cells to repair the large defect peri-implant after immediate implant.
authors.affiliation: Yantai Stomatological Hospital Yantai, China ; Department of Periodontology, School of Dentistry, Shandong University Jinan, China.
authors.forename: Peng-Jie
authors.initials: PJ
authors.lastname: Hao
authors.affiliation: The Affliated Hospital of Qingdao University Medical College Qingdao, China.
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Wang
authors.affiliation: The Affliated Hospital of Qingdao University Medical College Qingdao, China.
authors.forename: Quan-Chen
authors.initials: QC
authors.lastname: Xu
authors.affiliation: Yantai Stomatological Hospital Yantai, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Xu
authors.affiliation: Weihai Municipal Hospital Weihai, China.
authors.forename: Zhuo-Ri
authors.initials: ZR
authors.lastname: Li
authors.affiliation: Department of Periodontology, School of Dentistry, Shandong University Jinan, China ; Department of Endodontics, School of Dentistry, Shandong University Jinan, China.
authors.forename: Pi-Shan
authors.initials: PS
authors.lastname: Yang
authors.affiliation: Yantai Stomatological Hospital Yantai, China.
authors.forename: Zhong-Hao
authors.initials: ZH
authors.lastname: Liu
mesh_terms: D000818:Animals; D036101:Cord Blood Stem Cell Transplantation; D015921:Dental Implants; D019250:Dental Implants, Single-Tooth; D004285:Dogs; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*
chemical_list: D015921:Dental Implants
keywords: Umbilical cord mesenchymal stem cells; dental implant; immediate implant; peri-implant bone defect