Abstract:

BACKGROUND: Osteoporosis and smoking can increase dental implant failure rate significantly.
OBJECTIVE: To investigate the effect of estrogen on bone deposition around implants in osteoporosis rats undergoing cigarette smoke inhalation.
METHODS: Fifty 3-month-old female SD rats were randomly divided into five groups (n=10): sham operation group, ovariectomy group, ovariectomy+smoke inhalation group, ovariectomy+estrogen group and ovariectomy+smoke inhalation+estrogen group. Rats in all groups were subjected to ovariectomy except the sham operation group. After ovariectomy, the latter two groups were given cigarette smoke inhalation for 24 weeks. Then, screw-type titanium implants were placed into the right tibiae in rats at 12 weeks after ovariectomy or sham surgery. Next, rats in the ovariectomy+estrogen group and ovariectomy+smoke inhalation+estrogen group were injected with estradiol benzoate intramuscularly. After 24 weeks, before sacrificed, densitometry of the tibiae in rats was detected by X-ray test. After that the samples of dead rats were collected and the tibiae with implant were removed by hand-mill piece of bone implant for observation.
RESULTS AND CONCLUSION: The densitometry and X-ray results demonstrated that estradiol could improve bone deposition around implants. Hard tissue slicing observations result showed that in ovariectomy+estrogen group, the implants obtained good osseointegration, besides, cancellous bone area combined with bone lamella was connected with the trabecular bone. In addition, the bonding bone lamella in ovariectomy+smoke inhalation+estrogen group was thicker than that in ovariectomy+smoke inhalation group. Moreover, the amount of trabecular bone was increased. These results suggest that estrogen can improve the bone deposition around implants to a certain extent and promote implant osseointegration in osteoporosis rats undergoing cigarette smoke inhalation.