5-Aminolevulinic Acid Gel Associated with Light-Emitting Diode Modulates the <i>in Vitro</i> Subgingival Multispecies Oral Biofilm

<b><i>Objective:</i></b> This study assessed the impact of a 5% combination of 5-aminolevulinic acid (5-ALA) (Aladent) in a multispecies in vitro biofilm model subgingival pathogens. <b><i>Methods:</i></b> The 33-species biofilm model was established in the Calgary Biofilm Device during a duration of 7 days. The biofilm treatments comprised various groups: control, light-emitting diode (LED), Aladent (ALADA), and Aladent with LED (ALAD+L), administered on day 6. The Aladent was in contact with the biofilm for 45 min before to the 7-min LED treatment. The LED (λ = 630 nm, power ≈ 380 mW/cm²) was placed 2 mm from the biofilm. Subsequently, during 7 days of biofilm formation, the metabolic activity of the biofilms was assessed utilizing triphenyltetrazolium chloride, and the presence of 33 bacterial species was evaluated through DNA-DNA hybridization. <b><i>Results:</i></b> The findings indicated that the ALAD+L treatment was the sole intervention demonstrating a statistically significant reduction (∼70%) in the metabolic activity of the biofilms relative to the control group. Moreover, ALAD+L markedly diminished the overall biofilm count and the average counts of five bacterial species: <i>S. intermedius</i>, <i>V. parvula</i>, <i>A. israelii</i>, <i>P. gingivalis</i>, and <i>E. saburreum</i>. <b><i>Conclusion:</i></b> The integration of the photosensitizer Aladent with LED application significantly diminished metabolic activity and bacterial species count in the multispecies subgingival biofilm model, indicating substantial promise for the treatment of peri-implantitis.