Dihydrotestosterone Improves the Osseointegration of Cobalt-Chromium Implants

Background: The osseointegration of actually rarely implanted cobalt-chromium implants can be critical in an elderly population. The aim of our study was to evaluate the effect of preoperative testosterone treatment on the osseointegration of cobalt-chromium implants. Materials and Methods: Press-fit implantation of 1.6 mm-diameter cobalt-chromium-molybdenum (CoCrMo) implants was performed in rats without pre-treatment in one group (n = 10) and after pre-treatment with 1 mg dihydrotestosterone (DHT) 2 days before surgery in the other group (n = 10). After 14 days, the specimens were examined by a pull-out test, histology and histomorphometry. Results: The biomechanical testing delivered inconsistent data leading to no significant difference (6.45 +/- 6.94 N vs. 4.66 +/- 3.77 N). Histology showed closed contact between surrounding tissue and the implants in both groups. The bone/implant contact area was significantly enhanced after treatment with DHT (42.23% +/- 9.25 vs. 57.57% +/- 16.71, p < 0.05), while the ratio of osteoid was reduced (38.68% +/- 16.7 vs. 27.38% +/- 13.02, not significant). Conclusions: Pre-treatment with DHT enhances osseointegration of cobalt-chromium implants through enhanced mineralisation of peri-implant tissue. The treatment might additionally shorten postoperative rehabilitation due to its positive effects on musculature.