Alveolar Bone Loss One Year Following Ovariectomy in Sheep

Abstract

There is little information concerning the incidence of alveolar bone loss in estrogen‐deficient women. Ovariectomized sheep are valid models for study of the effects of estrogen deficiency on bone metabolism. The objective of this study was to compare alveolar bone loss in control (C) and ovariectomized sheep (OVX) at 3 and 12 months following surgery. OVX animals had decreased serum levels of 17‐βestradiol and increased serum levels of osteocalcin, IL‐6, and urinary levels of deoxypyridinoline which, taken together, suggest development of osteoporosis. The mean probing depths and percentage of sites with pocket depths 4 to 6 mm and >6 mm were significantly greater in OVX than C at each time period and in OVX were significantly greater at 12 months than at 3 months. Gingival tissue interleukin‐6 (IL‐6) levels (but not the number of IL‐6(+) cells) were elevated adjacent to deep periodontal pockets; however, there was no significant elevation of levels of the proinflammatory cytokines IL‐1β and IL‐8 within gingiva. Taken together, the data suggest a systemic contribution for progression of periodontal disease associated with estrogen deficiency. This may involve upregulation of systemic IL‐6 synthesis and transfer to gingiva in serum, resulting in enhanced IL‐6 accumulation within the gingival tissues or reduced bone density allowing for a greater amount of alveolar bone loss. J Periodontol 1997;68:864–871.

Genistein Prevents Bone Resorption Diseases by Inhibiting Bone Resorption and Stimulating Bone Formation

“…20) In our experiment, after treated with genistein, the serum level of IL-1 and TNFa had significant decrease compared with OVX rats (pϽ0.01), suggesting that genistein suppress the bone resorption. However, interestingly, different from several studies, [21][22][23] the serum level of IL-6 in our experiment had no changes, suggesting that there were some differences in the mechanism between genistein and estradiol. Some researchers have reported that IL-6 exerts its effect in the initial stage of osteoclasts differentiation, while IL-1 plays its role in the later phase.…”

Influence of different durations of estrogen deficiency on alveolar bone loss in rats

“…In sheep, Johnson et al 26 observed significant inflammatory periodontal alterations 90 days after ovariectomy compared with controls.…”

“…The peaks identified in different studies do not always coincide; peaks from 30 to 90 days have been reported. [26][27][28][29] The use of several time intervals in this study was appropriate to reveal the duration of estrogen deficiency that showed greater influence on the bone loss caused by induced periodontitis. Previous studies did not identify this relationship because of their use of a shorter period of time.…”

Long-term effects of ovariectomy on the properties of bone in goats

“…However, the time required to establish an accurate osteoporosis model remains inconsistent between studies. A number of previous studies (20)(21)(22)(23) have found that bone formation in sheep continues to decline between 10 weeks and 6 months after an ovariectomy, with certain studies reporting that the BMD significantly decreases 6 months after an ovariectomy (24); however, other studies have not observed these results (25).…”