ALVEOLAR BONE LOSS ONE-YEAR FOLLOWING OVARIECTOMY IN SHEEP

THERE IS LITTLE INFORMATION concerning the incidence of alveolar bone loss in estrogen-deficient women, Ovariectomized sheep are valid model s for study of the effects of estrogen deficiency on bane metabolism. The objective of this study was to compare alveolar bone loss in contr ol (C) and ovariectomized sheep (OVX) at 3 and 12 months following sur gery, OVX animals had decreased serum levels of 17-beta-estradiol and increased serum levels of osteocalcin, IL-6, and urinary levels of deo xypyridinoline which, taken together, suggest development of osteoporo sis. The mean probing depths and percentage of sites with pecker depth s 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 a t 3 months. Gingival tissue interleukin-6 (IL-6) levels (but not the n umber of lL-6(+) cells) were elevated adjacent to deep periodontal poc kets; however, there was no significant elevation of levels of the pro inflammatory cytokines IL-1 beta and IL-8 within gingiva. Taken togeth er, the data suggest a systemic contribution for progression of period ontal disease associated with estrogen deficiency. This may involve up regulation 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.