title: [Effect of nerve growth factor on the early phase of osseointegration around oral implants].
abstract: OBJECTIVE
  To observe the early bone integration of oral implants after injection of exogenous nerve growth factor (NGF) and investigate the effects of NGF on peri-implant osseointegration.
  
  
  METHODS
  Twelve New Zealand white rabbits were used in this study to establish bi-mandible implant model. Then local injection of 1 µg NGF was given on the right side of the mandible as experimental group and normal saline only was injected on the left side as control group once a day for seven days. The rabbits were respectively sacrificed at 2, 4 and 8 weeks after surgery. The implant-bone grinding samples were prepared and stained by toluidine blue for general observation, X-ray, histology and bone histomorphometry analysis.
  
  
  RESULTS
  The density of the new bone around implants at 2 and 4 weeks was lower than normal bone. Compared with the control group, the quantity of new bone and bone-implant contact ratio significantly increased in the experimental group. At 8 weeks, the new bone density in both groups was similar to the normal bone. In the experimental group, the haversian system was observed. Bone contact ratio was significantly different between experimental and control group at 2 and 4 weeks, but similar at 8 weeks.[control group at 2 weeks (26.67 ± 3.88)%, 4 weeks (52.59 ± 5.07)% and 8 weeks (97.33 ± 6.75)%, experimental group at 2 weeks (42.24 ± 6.67)%, 4 weeks (72.25 ± 6.30)% and 8 weeks (99.15 ± 4.68)%].
  
  
  CONCLUSIONS
  Applying exogenous NGF in the early phase could accelerate the formation and maturation of trabecular bone around the implants and shorten the period of osseointegration. Nerve growth factor could promote osseointegration in the early stage of oral implantation.
authors.affiliation: Department of Prosthodontics, Capital Medical University School of Stomatology, Beijing 100050, China.
authors.forename: Yan-na
authors.initials: YN
authors.lastname: Bao
authors.forename: Feng
authors.initials: F
authors.lastname: Huang
authors.forename: Xiao-fei
authors.initials: XF
authors.lastname: Tang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wen
authors.forename: Zhao-chen
authors.initials: ZC
authors.lastname: Shan
authors.forename: Jian-yu
authors.initials: JY
authors.lastname: Zeng
mesh_terms: D000818:Animals; D015519:Bone Density; D001842:Bone and Bones; D015921:Dental Implants; D008334:Mandible; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016348:Osseointegration; D019736:Prostheses and Implants; D011817:Rabbits
chemical_list: D015921:Dental Implants; D020932:Nerve Growth Factor