Targeting mixed-species biofilms of <i>Streptococcus mutans</i> and <i>Candida albicans</i> on clear aligners: boron-based natural substance combinations for enhanced antibiofilm efficacy
BIOFOULING, vol.42, no.6, pp.602-618, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 42 Issue: 6
- Publication Date: 2026
- Doi Number: 10.1080/08927014.2026.2680103
- Journal Name: BIOFOULING
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, Environment Index, Geobase, MEDLINE, Zoological Record
- Page Numbers: pp.602-618
- Keywords: biofilm, boric acid, Candida albicans, natural substances, orthodontic clear aligners, Streptococcus mutans
- Istanbul University Affiliated: Yes
Abstract
In orthodontic treatment, insufficiently cleaned clear-aligners can serve as reservoirs for biofilms. This study evaluates in-vitro biofilm models and investigates the antibiofilm efficacy of boron-based formulations with natural substances. Minimum inhibitory concentrations (MICs) were determined by microdilution, and Fractional inhibitory concentration by checkerboard methods. Biofilm inhibition was assessed at sub-MIC levels, and mature biofilm-eradication at supra-MICs. Time-kill assays were performed on mixed-biofilms of Streptococcus mutans and Candida albicans on clear-aligners. The MIC values of boric acid, sodium borate, and natural substances against S. mutans were 1,250-5,000, 4,000-8,000, and 2.5->10,000 mu g/mL, respectively. Synergistic combinations included eucalyptol, epigallocatechin-gallate, resveratrol, and cinnamaldehyde. Biofilm inhibition rates ranged from 49%-58%, and eradication concentrations were 8-16xMIC. A formulation containing boric acid reduced viable cells by >= 5-log10 in time-kill assays. These findings indicate that boron-based formulations with natural substances suggest notable antibiofilm activity against mixed-species biofilms and may provide preliminary in vitro data for aligner-cleaning or oral-care products.