title: Effect of estrogen deficiency on the fixation of titanium implants in chronic kidney disease mice.
abstract: We established a chronic kidney disease (CKD) mouse model with estrogen deficiency and inserted titanium implants into the femur of such mice to investigate the fixation of the implants. Both the histomorphometry and implant resistance indicated that estrogen deficiency impaired the fixation of titanium implants inserted into such mice.
  
  
  BACKGROUND
  CKD has been regarded as a worldwide public health problem. Estrogen is a critical factor for both renal protection and bone remodeling. A previous study demonstrated that CKD impairs the early healing of titanium implants. However, the combined effect of estrogen deficiency and CKD on the fixation of titanium implants is largely unknown.
  
  
  METHODS
  Forty 9-week-old female C57BL mice were randomly divided into sham, ovariectomy (OVX), CKD, and CKD + OVX groups. Uremia and estrogen deficiency were induced by 5/6 nephrectomy and OVX, respectively. Experimental titanium implants were inserted into the distal end of the femur. Bone-implant contact (BIC) ratio and bone volume (BV/TV) around the implants were histomorphometrically analyzed. The fixation strength of the implant was measured by a biomechanical push-in resistance test.
  
  
  RESULTS
  Serum measurement confirmed a significant increase in serum blood urea nitrogen (BUN) in the CKD group, which was further increased by OVX. Estrogen deficiency led to significant decreases in the BIC ratio, BV/TV, and the push-in resistance in CKD animals. There was a significant interaction between the effects of OVX and CKD, with OVX exacerbating the effects of CKD on BIC ratio and push-in resistance.
  
  
  CONCLUSIONS
  The results indicated that estrogen deficiency exerts a synergistic effect with CKD and further impairs the fixation of titanium implants in CKD mice.
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, 14 Third Section, Renmin Nan Road, 610041, Chengdu, China.
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.forename: H
authors.initials: H
authors.lastname: Zou
authors.forename: N
authors.initials: N
authors.lastname: Sun
authors.forename: D
authors.initials: D
authors.lastname: Zhao
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Dong
authors.forename: G
authors.initials: G
authors.lastname: Cheng
authors.forename: Q
authors.initials: Q
authors.lastname: Yuan
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D005269:Femur / Q000601:surgery; D006614:Hindlimb / Q000601:surgery; D020007:Implants, Experimental; D051379:Mice; D008810:Mice, Inbred C57BL; D016348:Osseointegration / Q000502:physiology*; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology*; D014025:Titanium / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D004967:Estrogens; D014025:Titanium