Osseointegration of Superhydrophilic Implants Placed in Defect Grafted Bones

Purpose: Only limited information on the effect of implant surface hydrophilicity in conjunction with simultaneous bone augmentation is available. In this study, new bone growth around implants with a superhydrophilic modSLA (SLActive) and hydrophobic SLA (SLA) surface were compared in circumferential defects when grafted in conjunction with mineralized cancellous bone allograft (MCBA, maxgraft) or sintered bovine bone mineral (SBBM, cerabone). Materials and Methods: The osseointegration and bone formation in circumferential defects in minipig mandibles around Straumann Roxolid, Ø 3.3 mm, length 8 mm, either SLA or SLActive, were evaluated. Following implant placement, the 2-mm circumferential defects around the implants were filled with MCBA or SBBM. The distance from the implant shoulder to first bone-to-implant contact (f-BIC), percentage of bone-to-implant contact (BIC), and bone aggregate percentage (amount of new bone and remaining graft) within the defect area were evaluated after 8 weeks of healing. Results: In the SBBM group, lingual f-BIC and buccal BIC were significantly lower for SLA (mean -0.404 ± 0.579 mm for modSLA vs -1.191 ± 0.814 mm for SLA, P = .021, and mean 62.61% ± 9.49% for modSLA vs 34.67% ± 24.41% for SLA, P = .047, respectively). Bone aggregate percentage was significantly higher for modSLA vs SLA implants in SBBM (77.84% ± 6.93% vs 64.49% ± 13.12%, P = .045). The differences between implant surfaces in MCBA showed a similar trend but were less pronounced than in the SBBM group and did not reach a statistically significant level. Conclusion: The results suggest that implants with a superhydrophilic modSLA surface are more conducive to faster osseointegration even in conjunction with simultaneous bone grafting procedures. Keywords: bone graft, guided bone regeneration, histology, hydrophilicity, surface