Bisphosphonate-related osteonecrosis associated with dental implants: a microcomputed tomography study.

PURPOSE: The aims of this study were to quantify bone mineral density (BMD) and trabecular architecture of sequestra in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) associated with dental implants and to assess if there are differences between trabecular bone in "implant loading-triggered" and "implant surgery-triggered" BRONJ. MATERIALS AND METHODS: Bone sequestra of 2 patients diagnosed with BRONJ associated with dental implants were scanned using high-resolution microcomputed tomography (microCT). Images were obtained at a voltage of 50 kV and 800 μA, and the specimens were scanned at 180 degrees with a single rotation step of 0.3, 1-mm aluminum filter, and a pixel size of 12 μm. The morphometric parameters examined were: BMD, ratio of bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), connectivity density (Conn.D, mm), degree of anisotropy, and the structural model index. RESULTS: BMD and BV/TV were higher in bone sequestration than in healthy bone. Tb.Sp was lower and Tb.N and Tb.Th were higher in the BRONJ group. Conn.D and Tb.N values were significantly high in implant surgery-triggered sequestrum but substantially low in sequestra caused by loading as compared with those of the control sample. CONCLUSIONS: MicroCT is useful for assessing bone sequestration of BRONJ associated to dental implants. The necrotic bone is similar to that described in conventional BRONJ.