Lucía López-Polín

Bone in archaeological or paleontological sites is often prone to degradation during the taphonomic phases (before and after the burial process until its discovery) which significantly weakens the bone’s mechanical properties. To preserve the material, consolidation treatments are commonly applied during ̶excavations to improve the cohesion of friable material. Studies on the effectiveness of bone consolidation treatments are relatively scarce. This research provides the first comparative analysis of the effectiveness of consolidation among three bone consolidation products (Acril 33®, Paraloid B72®, and Nanorestore®) applied by three different methods (capillary, immersion, and drip). Consolidation effectiveness was analyzed by the characterization of the absorption (water-drop absorption), contact angle measurements, environmental scanning electron microscopy, observation of the ability to penetrate the bone microstructure, by 3D visible light microscopy (HIROX 8700), and Leeb hardness measurements for the determination of mechanical strength improvements. Results show that the aqueous resin Acril 33® tends to provide a low penetration depth, creating a rigid superficial layer over the samples regardless of the application method, which seriously compromises the overall consolidation effectiveness. On the contrary, samples treated with Paraloid B72® present a higher penetration depth and increase the mechanical properties of samples applied by capillarity and immersion. Nanorestore® induced a significant increase in surface hardness regardless of the application method.