The Implant Surface and Its Role in Affecting the Dynamic Processes of Bone Remodeling by Means of Distance Osteogenesis: A Comparative In Vivo Study

Daniel G. E. Thiem, Dr Med, Dr Med Dent, MD, DDS/Martin Adam, Dr rer nat, DS/Cornelia Ganz, Dr rer nat, DS/Thomas Gerber, Prof Dr rer nat, DS, PhD/Peer W. Kämmerer, Priv-Doz. Dr med habil Dr Med Dent, MD, DDS, PhD, MA: Purpose: This study aimed to evaluate whether different surface modifications affect the dynamics of bone remodeling at the implant and the adjacent local bone. Materials and Methods: Seventy-two dental implants with different surfaces (smooth and rough control [smCtrl; rCtrl], smooth and rough + O2 - plasma spray [smPlas; rPlas], smooth and rough + nanocrystalline SiO2 - hydroxyapatite - coating [ncSiO2HA] + O2-plasma spray [smNB-C; rNB-C]; each n = 12) were bilaterally inserted into the femora of 36 New Zealand white rabbits. Intravital fluorochrome labeling was performed to visualize the dynamics of bone formation. The objectives were quantification of bone-to-implant contact (BIC %) at 2 and 4 weeks and the dynamic bone formation (dbf %) at the implants’ adjacent local bone within 1, 2, and 3 weeks. Results: After 2 weeks, BIC was significantly higher for both smNB-C (BIC: 59% ± 2% standard error of the mean [SEM]) and rNB-C (BIC: 66% ± 3% SEM) compared with controls (BIC: 42% ± 1% SEM; P < .005). After 4 weeks, BIC for rNB-C (65% ± 2%) was superior to all test groups (BIC: 39% ± 2% SEM; P = .012). Regarding dbf (%), no differences occurred within 1 (P = .88), or 2 (P = .48), or after 3 weeks (P = .36) among the groups even in accordance to the implant level. Conclusion: Although distance osteogenesis seems crucial for the development of secondary stability, and thus, of osseointegration, it apparently is not affected by a bioactive ncSiO2HA surface coating. Changing the surfaces’ release kinetics and composition may increase distance osteogenesis.