Oki Yoshifumi, Doi Kazuya, Makihara Yusuke, Kobatake Reiko, Kubo Takayasu, Tsuga Kazuhiro
Hiroshima University, Graduate School of Biomedical & Health Sciences, Department of Advanced Prosthodontics, Division of Dental Sciences, Hiroshima, Japan.
J Appl Oral Sci. 2017 Sep-Oct;25(5):498-505. doi: 10.1590/1678-7757-2016-0561.
This study aimed to evaluate the effects of continual intermittent administration of parathyroid hormone (PTH) on implant stability in the presence of osteoporosis, using rabbit models.
Fifteen female New Zealand white rabbits underwent ovariectomy and were administered glucocorticoids to induce osteoporosis, following which they were divided into three groups. The first group received intermittent subcutaneous PTH for 4 weeks until implant placement (PTH1), while the second and third groups received PTH (PTH2) and saline (control), respectively, for 4 weeks before and after implant placement. After intermittent administration of PTH or saline, titanium implants were inserted into the left femoral epiphyses of all animals, and the implant stability quotient (ISQ) was measured immediately after placement to assess the primary stability and at 2 and 4 weeks after implant placement to assess osseointegration. At 4 weeks after implant placement, histological and histomorphometric evaluations were conducted and the bone area around the implant socket was measured as a ratio of the total bone area to the total tissue area.
Regarding primary stability, the ISQ values for the PTH1 and PTH2 groups were significantly higher than those for the control group (p<0.05). Concerning osseointegration, the ISQ values at 2 and 4 weeks were significantly higher for the PTH2 group than for the PTH1 and control (p<0.05) groups. Histological assessments showed a thicker and more trabecular bone around the implant sockets in the PTH2 specimens than in the PTH1 and control specimens. The bone area around the implant socket was significantly greater in the PTH2 group than in the PTH1 and control groups (p<0.05).
Our results suggest that continual intermittent PTH administration before and after dental implant placement is effective for the achievement of favorable stability and osseointegration in the presence of osteoporosis.
本研究旨在利用兔模型评估在骨质疏松情况下持续间歇性给予甲状旁腺激素（PTH）对种植体稳定性的影响。
15只雌性新西兰白兔接受卵巢切除术，并给予糖皮质激素以诱导骨质疏松，随后将它们分为三组。第一组在种植体植入前接受4周的间歇性皮下注射PTH（PTH1），而第二组和第三组分别在种植体植入前后4周接受PTH（PTH2）和生理盐水（对照组）。在间歇性给予PTH或生理盐水后，将钛种植体植入所有动物的左股骨骨骺，在植入后立即测量种植体稳定性商数（ISQ）以评估初期稳定性，并在植入后2周和4周测量以评估骨整合情况。在植入后4周，进行组织学和组织形态计量学评估，并测量种植体窝周围的骨面积，以其占总骨面积与总组织面积的比例表示。
关于初期稳定性，PTH1组和PTH2组的ISQ值显著高于对照组（p<0.05）。关于骨整合，PTH2组在2周和4周时的ISQ值显著高于PTH1组和对照组（p<0.05）。组织学评估显示，PTH2组标本中种植体窝周围的骨小梁比PTH1组和对照组标本中的更厚且更多。PTH2组种植体窝周围的骨面积显著大于PTH1组和对照组（p<0.05）。
我们的结果表明，在牙种植体植入前后持续间歇性给予PTH对于在骨质疏松情况下实现良好的稳定性和骨整合是有效的。
