Influence of Dental Titanium Implants with Different Surface Treatments Using Femtosecond and Nanosecond Lasers on Biofilm Formation

Abstract

This study aimed to evaluate the impact of different surface treatments (machined; sandblasted, large grit, and acid-etched (SLA); hydrophilic; and hydrophobic) on dental titanium (Ti) implant surface morphology, roughness, and biofilm formation. Four groups of Ti disks were prepared using distinct surface treatments, including femtosecond and nanosecond lasers for hydrophilic and hydrophobic treatments. Surface morphology, wettability, and roughness were assessed. Biofilm formation was evaluated by counting the colonies of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi) at 48 and 72 h. Statistical analysis was conducted to compare the groups using the Kruskal-Wallis H test and the Wilcoxon signed-rank test (α = 0.05). The analysis revealed that the hydrophobic group had the highest surface contact angle and roughness (p < 0.05), whereas the machined group had significantly higher bacterial counts across all biofilms (p < 0.05). At 48 h, the lowest bacterial counts were observed in the SLA group for Aa and the SLA and hydrophobic groups for Pg and Pi. At 72 h, low bacterial counts were observed in the SLA, hydrophilic, and hydrophobic groups. The results indicate that various surface treatments affect implant surface properties, with the hydrophobic surface using femtosecond laser treatment exerting a particularly inhibitory effect on initial biofilm growth (Pg and Pi).

Keywords: biofilm formation; dental implants; femtosecond laser; nanosecond laser; surface roughness; surface treatment.

Figure 1

Laser systems for hydrophilic and hydrophobic surface treatments. (A): femtosecond laser system. (B): Nanosecond laser system.

Figure 2

Representative surface contact angle image. (A): Machined group. (B): SLA group. (C): Hydrophilic group. (D): hydrophobic group.

Figure 3

Representative surface morphology image using SEM. (A): Machined group. (B): SLA group. (C): Hydrophilic group. (D): Hydrophobic group.

Figure 4

Representative surface morphology image using confocal laser scanning microscopy. (A): Machined group. (B): SLA group. (C): Hydrophilic group. (D): Hydrophobic group.

Figure 5

Comparison of relative biofilm formation ratios in relation to the machined group. * Significant differences between each group and machined group determined using the Mann-Whitney U-test, p < 0.05.