In Vitro Antifungal Efficacy of Blue-Light Photodynamic Therapy with Curcumin and Riboflavin Formulation Activated by 450 nm Diode Laser Against Candida albicans Biofilm on Titanium Implants.

Background

Candida albicans is increasingly recognized in peri-implantitis due to its capacity to form resilient biofilms on implant surfaces, limiting treatment success. Antimicrobial photodynamic therapy (aPDT) may offer a non-invasive adjunct by leveraging photosensitizer activation to produce reactive oxygen species that disrupt microbial cells. This in vitro study assessed the antifungal efficacy of QroxB2, a dual-photosensitizer containing riboflavin and curcumin, activated by 450 nm blue light against C. albicans biofilms on titanium implants.

Methods

C. albicans biofilms were formed on 63 titanium implants and randomly assigned to nine groups (n = 7): untreated control (GC), chlorhexidine (CHX), riboflavin (RIB), curcumin (CUR), QroxB2 (QBX), laser only (L), and three photodynamic therapy groups combining laser irradiation with each photosensitizer (L + RIB, L + CUR, L + QBX). Treatments were followed by colony-forming unit (CFU) enumeration.

Results

The L + QBX group showed the strongest antifungal effect, achieving a 94% reduction in fungal load, with median CFU counts decreasing from 49,000 in the untreated control to 2800 CFU/mL. CHX eradicated all viable cells (0 CFU/mL). Among photosensitizer-only groups, QBX produced a moderate reduction (median 21,800 CFU/mL), whereas laser irradiation alone (L) exhibited no meaningful antifungal activity, with median counts comparable to the untreated control (49,000 CFU/mL).

Conclusions

QroxB2-mediated aPDT achieved a significant reduction in Candida albicans colony-forming units on implant surfaces. While not as potent as chlorhexidine, this light-activated, biocompatible approach may serve as a complementary tool in managing peri-implant fungal infections. Clinical validation is warranted.