Porous titanium–silver dental implants fabricated via SPS: Poly-caprolactone coating and bioevaluation

Abstract Titanium implants are among the most widely used implants in dentistry; however, their use is associated with difficulties. Among the challenges in the construction and application of these implants, three important ones are considered in this study: (1) reducing construction temperature and time, (2) decreasing infection rate after implant loading, and (3) eliminating stress shielding. The first stage is making pieces of Ti–1 wt% Ag by spark plasma sintering at 850 and 900°C and pressure of 10 and 30 MPa. In the second stage, by sol–gel and immersion, poly-caprolactone was placed on the surface. For characterization, porosity, hardness, compressive strength, corrosion, and wettability were evaluated, and X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared, field emission scanning electron microscopy, antibacterial test, and MTT were performed. XRD results indicated that the addition of 1% Ag to Ti did not change the crystalline phase. Also, Ag is completely dissolved in the structure of Ti and forms a substitutional solid solution. SEM results showed that samples made at 850°C and 10 MPa had 20–25% porosity. The average size of porosities is 5 μm with a morphology similar to interconnected spheres. Hardness and compressive tests showed that the best manufacturing conditions were 850°C and 10 MPa. After etching and coating, the samples have the highest wettability rate. Results of electrochemical tests showed that the corrosion potential of Ti–1 wt% Ag with coating is higher than the uncoated structure. In the cytotoxicity test, cell viability was improved by coating. Antibacterial test indicates that the coated sample is able to kill bacteria.