The Effects of Implant Surface Characteristics on Surrounding Bone: A Comparative Study of Two Types of Surface Characteristics

Abstract

The aims of this study were to create experimental implants by coating rough plastic surfaces with a thin layer of titanium, and to use the experimental implants in an animal experiment to investigate whether differences in the surface characteristics of the implant affect the peri-implant bone reaction during the period of osseointegration. Titanium rods of diameter 1.6 mm and length 7 mm were treated by acid etching (AE) or sandblasting followed by acid etching (SA), and replicas were made from plastic. Experimental implants were created by depositing a thin layer of titanium on the plastic replicas by DC-magnetron sputtering, and the surface characteristics of the experimental implants were evaluated. The experimental implants were placed in the tibias of eight-week-old male SD rats. The rats were sacrificed and the implants harvested at 3, 5, 10, 14, 21 and 28 days after implant placement. The samples were examined by optical microscopy and micro-CT to confirm peri-implant new bone growth. Examination of the experimental implants by SEM imaging showed that the different surface conditions (SA and AE) had been faithfully recreated. TEM observation and XPS analysis confirmed that the coating was titanium. The surface roughness of SA and AE was 2.68±0.536 μm and 0.47±0.069 μm, respectively. With AE, the BMD of peri-implant trabecular bone showed that bone mineralization progressed not on the surface of the implant but at sites a small distance away. At day 28 after placement of the implant, when osseointegration was complete, the BMD value in the region near the implant surface was higher in SA than in AE. Furthermore, the BV/TV value was high at an earlier stage in SA than AE. The results showed that the SA surface was better than the AE surface for achieving osseointegration.