Surface parameters of as-built additive manufactured metal for intraosseous dental implants

Abstract

Statement of problem: To improve osseointegration, current machined implants are submitted to different surface treatments such as airborne-particle abrasion and acid etching. Although additive manufacturing has allowed the fabrication of implants with custom design, porosity, and roughness, whether good osseointegration can be achieved without subsequent surface treatments is still unclear.

Purpose: The purpose of this in vitro study was to investigate the feasibility of using additive manufacturing technology for dental implants without the use of subsequent surface treatments.

Material and methods: The roughness, wettability, and surface energy of a flat test stainless-steel specimen produced from a 3D printer were evaluated. The roughness measurements were obtained by using a mechanical contact profilometer. The wettability was characterized by the sessile drop method by using deionized water and ethylene glycol. The surface energy values were calculated by using the Owens, Wendt, Rabel, and Kaeble (OWRK) computational method.

Results: The experimental data obtained were R_a=4.55 μm, R_q=5.64 μm, R_Sm=0.235 mm, R_sk=-0.071, R_ku=3.740, R_dq=13 degrees; water contact angle=66 degrees; ethylene glycol contact angle=57 degrees; surface energy=38 mN/m. The measured values were compared with data reported in the literature for commercially available implants. The parameter R_a, which is the most used parameter to describe the surface of dental implants, was 50%, 270%, and 329% higher than that reported in the literature for commercial dental implants. The surface energy was 10% and 19% lower than the representative values in the literature for commercial dental implants.

Conclusions: The results indicate that specimens fabricated by additive manufacturing had higher roughness and lower surface energy than reported results in the literature. Therefore, additive manufacturing was found to produce suitable surface parameters for dental implants, and subsequent surface treatments could be removed from the manufacturing process.