Clin Oral Investig. 2025 Oct 11;29(11):497. doi: 10.1007/s00784-025-06580-2.
ABSTRACT
OBJECTIVE: To evaluate the influence of different surface roughness levels of titanium disks, induced by alumina blasting, on bacterial adhesion.
MATERIALS AND METHODS: Twelve different surface roughnesses, ranging from 0.01 μm to 6 μm, were produced using a shot blasting technique with varying alumina particle sizes. Surface roughness was measured using confocal interferometry, wettability was assessed by contact angle measurements, and compressive residual stress was evaluated by X-ray diffraction. For each roughness level, 720 samples were used to culture Porphyromonas gingivalis (Gram-negative, anaerobic) and Streptococcus sanguinis (Gram-positive, anaerobic). The colonies formed per unit area, the ratio of dead bacteria to total bacteria, and the metabolic activity for each roughness ere determined.
RESULTS: The polished surface (Sa = 0.01 μm) showed the highest bacterial adhesion for both strains compared to the 0.13 μm roughness, which exhibited a antibacterial activity, likely due to nanostructured peaks causing bacterial membrane disruption. For surface roughness values between 0.5 and 3 μm, Gram-positive bacterial colonies increased approximately threefold. When the roughness exceeded 3.8 μm, colony formation rose fivefold. In contrast, Gram-negative bacteria did not exhibit statistically significant changes in adhesion between 0.5 and 2 μm. However, beginning at 2.6 μm, a marked increase was observed, with colony numbers reaching nearly four times the control at 6 μm. The ratio of dead bacteria and metabolic activity confirms bacterial colonization studies (CFU/mm2).
CONCLUSIONS: Surface roughness significantly influenced bacterial colonization on titanium implants. An antibacterial effect was observed at a roughness of 0.13 μm. Bacterial adhesion increased moderately up to 2.1 μm for Gram-negative and 3 μm for Gram-positive strains, followed by a sharp rise at higher roughness values. An optimal surface roughness range of 1 to 2 μm appears to promote favorable osteoblastic response while minimizing bacterial adhesion.
CLINICAL RELEVANCE: These results enhance our understanding of how implant surface roughness influences bacterial adhesion. This knowledge could contribute to the development of clinical approaches designed to lower the risk of peri-implantitis.
PMID:41075034 | DOI:10.1007/s00784-025-06580-2
