Fibrin clot extension on different implant materials and surfaces: a quantitative in vitro study

Introduction: After placement, medical implants get exposed to the patient’s blood and the subsequent interactions with surface of the foreign implant material will influence the extent of blood coagulation fibrin network formation and acute inflammation Implant surface topography in the nano- to micro-scale tends to positively affect bioreactions and bone growth. Both chemistry and topography of the medical implant surfaces were demonstrated to be able to influence interactions with all blood components. Hence, the implant osseointegration might be directly influenced by the physicochemical properties of the implant surface 5,7.Aims: To evaluate and compare surface roughness (Ra), static contact angle(Ө) and blood clot extension (bce), forty disk-shaped samples of sandblasted yttria-tetragonal-zirconia-polycrystal (sb-YTZP), machined titanium (m-Ti) and plus titanium (p-Ti) were used. A 0.2 ml of human venous blood, immediately dropped onto the specimen’s surface was used to measure the bce. Contact time was 5 minutes at room temperature. Specimens were observed under a confocal scanning laser microscopy and scanning electron microscopy. Findings: Ra (mean ± SD μm) was 0.56±0.7 for m-Ti, 3.78±0.8 for p-Ti and 2.68±0.6 for sb-YTZP. The difference was not significant only between sb-YTZP and p-Ti. Ө (mean ± SD) was 55.6±5.6 for m-Ti, 48.7±2.8 for sb-YTZP and 38.0±2.2 for p-Ti. The difference was not significant only between m-Ti and sb- YTZP. bce (mean x 107±SD x 106 μm2) was 2.97±6.68 for m-Ti, 5.64±6.83 for p-Ti and 3.61±7.67 for sb- YTZP. p-Ti samples showed a significant higher blood clot extension. Conclusions: The p-Ti surface showed the higher amount of bce associated to the higher Ra and the lower Ө . More than the material type, both implant surface morphology and free energy seams to influence the blood clot extention. Further researches for blood-biomaterial nano-scale level interactions are necessary.