Distribution and Chemical Nature of Al₂O₃ Residues Following the Sandblasting Process: An In Vitro Study Using SEM,...

Osseointegration is a fundamental requirement for the long-term success of dental implants. Several implant systems have demonstrated excellent clinical outcomes over time, confirming their high reliability in the treatment of edentulism, even in patients with chronic disease. The success of these devices is closely linked to the characteristics of the implant surface, which directly influence the biological response of the surrounding bone.

The primary objective of this study was to investigate the presence of foreign material on the surface of dental implants following aluminum oxide sandblasting and subsequent surface treatment procedures. This analysis was conducted using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) to characterize the surface morphology and elemental composition. The secondary objective was to evaluate the cytotoxic potential of the implant surface through in vitro assays, in accordance with ISO 10993-5:2009, to assess its biocompatibility and suitability for clinical application.

Twenty threaded screw-shaped sandblasted Grade 5 titanium dental implants Dental Implant Advance 4.2 × 11.5 mm (Kinetical Implant, Buenos Aires, Argentina) for SEM combined with EDS, in order to identify the presence of possible organic contaminants or residues of the surface treatment process. Another 20 dental implant samples of the same type (4.2 × 11.5 mm) were used for the cytotoxicity test.

SEM analysis revealed a surface morphology consistent with sandblasting treatment, characterized by uniform roughness. However, particles with irregular shapes were observed in certain areas. Aluminum oxide particles were observed adhering to the surface of the implant. The cell viability percentages for each group were as follows: vehicle, 100.0%; negative control (HDPE), 96.0%; positive control (latex), 0.24%; and test samples, 96.9%. Based on the results obtained, the test sample did not show any relevant cytotoxic effects, maintaining a cell viability above 70% and OD values comparable to the negative controls. Therefore, it can be considered noncytotoxic in accordance with ISO 10993-5.

In conclusion, these findings indicate that the presence of residual alumina particles, resulting from the sandblasting process, does not exert a negative impact on cellular viability. Consequently, such residues can be considered not cytotoxic under the tested conditions, supporting the biocompatibility of the implant surface.