Comparison of early osseointegration of SLA®and SLActive®implants in maxillary sinus augmentation: a pilot study

Abstract Objective To assess the impact of a hydrophilic implant surface ( SLA ctive ® ) placed into augmented maxillary sinuses on bone‐to‐implant contact ( BIC ) and surrounding tissue composition when compared to a hydrophobic surface ( SLA ® ). Material and methods Four sheep underwent bilateral sinus augmentation. Each sinus received anorganic bovine bone mineral + autogenous bone ( ABBM + AB ). Sixteen implants were subsequently placed 12 weeks postgrafting with each sinus receiving a control ( SLA ® ) and test implant ( SLA ctive ® ). Two animals were sacrificed at 2 weeks and another two animals were sacrificed at 4 weeks postimplantation. The eight sinuses and 16 implants were processed for histomorphometry, which assessed bone‐to‐implant contact (% BIC ) and tissue elements (woven bone – WB , lamellar bone – LB , soft tissue – ST ) in the interthread region of implants within the augmented sinus. Results There was a statistically significant increase in % BIC at week 4 compared to the week 2 animals in both test ( P < 0.005) and control ( P < 0.005) groups. There was a statistically significant greater % BIC around test implants when compared to control implants in both week 2 ( P < 0.05) and week 4 animals ( P < 0.05). Greater % WB (11.17% ±6.82) and % LB (11.06% ±3.67) were seen in the test implants when compared to the control implants independent of time. This was only statistically significant for % LB ( P < 0.05). A statistically significant reduction of 16.78% (±6.19) in % ST was noted in test implants when compared to control implants ( P < 0.05) independent of time. Conclusion Both time and the use of hydrophilic implant surface had a positive impact on % BIC around implants placed into augmented maxillary sinuses. Hydrophilic implant surfaces also had a positive impact on surrounding tissue composition. Larger trials are needed to better assess and detect differences between these two surfaces in augmented maxillary sinuses.