Superficial properties of Ti6Al4V discs obtained by the additive and subtractive manufacturing method

Background

Rapid prototyping, also known as additive manufacturing (MA) or 3D printing, is a rapidly expanding manufacturing technology with great potential for different medical and dental applications. The technique of laser selective fusion (SLM) is the most recent method of MA that can be used in the manufacture of customized dental implants, being the main difference of 3D implants compared to 2D models, the surface.

Aim/Hypothesis

The objective of this study was to evaluate and compare the physico-chemical and mechanical properties of Ti-6Al-4V discs obtained by the additive manufacturing, Selective Laser Melting (SLM), and subtractive manufacturing by conventional machining.

Materials and Methods

Were used 30 discs (n = 10), divided into 3 groups- additive manufacture by SLM (DSLM) (Ø 5 mm ◊ 1 mm) + conventionally machined without surface treatment (DCM) and conventionally machined with surface treatment H3PO4 + NaOH (DCMST) (Ø 8 mm ◊ 3 mm). In order to characterize the surfaces, Scanning Electron Microscopy (SEM), X-ray Dispersive Energy Spectroscopy (EDS), surface roughness by confocal laser microscopy and wettability by a goniometer were performed. ANOVA and Tukey's test (α=0.05) were used for the quantitative analysis.

Results

MEV images showed a rougher surface of the DSLM, with unfused spherical particles, the DCMST topography similar to a sponge or coral, characteristic of applied nanometric treatment and DCM, polished surface. EDS demonstrated the presence of the essential elements of the alloy (Ti, Al and V) in the DCM and DSLM, in the DCMST also showed the presence of Na. For the roughness parameters (Ra and Sa), DUCMST (0.17 and 0.18 μm) and DCM (0.06 and 0.07 μm) were similar (P = 0.974), the highest mean was observed for DSLM (9.09 and 11.03 μm) (P < 0.001). For wettability, the DCMST had the lowest contact angle (18.55º) and the DSLM had the highest (103,23º) (P < 0.001).

Conclusion and Clinical Implications

Although MA presents innumerable advantages inherent in the technique, such as the possibility of product customization, waste reduction, energy consumption and duration of surgeries, in the present study, the MA promoting greater roughness and less hydrophilicity in DSLM discs. Thus, further studies should be performed to ensure the effectiveness of this technique in dentistry.