Association of sex steroid hormones and new bone formation rate after iliac onlay grafting: a prospective clinical pilot study.

PURPOSE: The present prospective study evaluates the association between new bone formation rate in the iliac onlay graft and sex steroid hormone serum levels. METHODS: A total of 15 partially or completely edentulous postmenopausal females and 9 males with less than 5 mm height of the remaining alveolar bone underwent iliac onlay grafting followed by dental implant placement using a two-stage approach. Sex hormone binding globulin and 17beta-estradiol serum levels were investigated by electrochemiluminescence immunoassay, while total testosterone level was analyzed using radioimmunoassay. At the time of implant placement, 12 weeks after grafting, bone biopsies were obtained and analyzed histomorphometrically. Statistical analysis was performed using linear mixed models. RESULTS: Grafting procedure was successfully performed in all patients. The mean new bone formation rate was 32.5% (116 samples). In men the mean new bone formation rate (38.1%) was significantly higher (p < 0.01) than in women (27.6%). Independent of gender 17beta-estradiol and testosterone were positively associated to overall new bone formation rate, albeit a significant influence was only seen for 17beta-estradiol in men (p = 0.020). Sex hormone binding globulin had no influence on new bone formation rate (p = 0.897). There was no significant association between new bone formation rate and age (p = 0.353) or new bone formation rate and body mass index (p = 0.248). CONCLUSION: Positive association of 17ss-estradiol as well as testosterone with new bone formation rate after iliac onlay grafting indicates a role of sex steroid hormones in alveolar bone regeneration, although the observed influence was only significant for 17ss-estradiol in men.