In vitro Osteoblast Attachment to Four Proprietary Implant Surfaces

Commercially available implant surfaces differ microscopically and in vitro studies showed surface characteristics affect adhesion, spreading, proliferation, differentiation and osteoblastic-matrix-production of osteoblast-like-cells (OBLC). Objective: This study compared attachment and spreading of human OBLC on four proprietary implant surfaces. Methods: Implants used were grit blasted (SI) from Southern Implants and from Nobelbiocare TiUnite™ (TU), machined (MN) and hydroxyapatite-coated (HA). Six of each was used. Bone fragments obtained from human mandibular bone during implant placement were used for OBLC cultivation. Two OBLC-lines from two individual patients were cultivated after informed consent. The osteoblast-like-nature was confirmed by calcium-mineral deposit formation. Calibrated suspensions were seeded onto defined surface areas. After 2, 6 and 12 hour's incubation, surfaces were washed twice with PBS, fixated and prepared for scanning electron microscopy (SEM). SEM images of 3-6 fields (1000x magnification) were taken to study the number and morphology of attached cells using Analysis® software. Data were compared by ANOVA using Statistix8® software. Results: Number of attached cells differed inconsistently (1.5-4.75 cells/field) except for HA that showed no cell attachment. Cell spreading significantly (p< 0.05) progressed with time intervals 2, 6 and 12 hours, except for MN (6h-12h). spread significantly better (p<0.05) compared to cell-line-2. This was confirmed with surface area measurements. For line-1 spreading on TU and SI was not significantly different (p>0.05) but significantly better than on MN at 2 and 12 hours (p<0.05). For line-2 spreading was better on SI than on TU (p>0.05), followed by ignificantly less spreading on MN (p<0.05). Conclusion: Non-transformed OBLC showed better spreading on enhanced surfaces. This may be the reason for quicker and better osseointegration seen clinically.