Antibiofilm Substantivity of AgNPs in Clinical Oral Biofilms from Patients with Motor and Intellectual Disabilities: An In Vitro and Exploratory Study

Background: Motor and intellectual disabilities (MIDs) belong to a restricted and vulnerable social group with health restrictions for maintaining and preserving adequate oral health. Silver nanoparticles (AgNPs) have appeared as an encouraging therapy due to their excellent antimicrobial effects; however, scientific information on the antimicrobial effectiveness of AgNPs against bacteria in patients with MIDs remains limited. This study aimed to evaluate the antimicrobial substantivity of AgNPs in oral bacteria from patients with and without MIDs. Methods: Fifty-four oral biofilm samples were obtained from 26 participants with MIDs and 28 participants without MIDs. The microbial inhibition activity and the antimicrobial substantivity of AgNPs were determined. The antibiofilm activity of the AgNPs was explored using scanning electron microscopy (SEM). Results: The AgNPs displayed uniform size distributions (9.8 ± 1.7 nm) and electrical charges in surface particles that limit particle clustering (−39.8 ± 3.3 mV). The AgNPs were more effective than chlorhexidine (CHX) in eliminating bacteria from oral biofilms derived from both MID and non-MID patients (p < 0.05); therefore, the antimicrobial substantivity of the AgNPs was statistically better than deionized water but lower than CHX at specific exposure times (p < 0.05). The antimicrobial effectiveness of AgNPs at even low concentrations was associated with the type of oral biofilm, the type of antimicrobial solution, and, in some cases, gender. SEM images indicate a clear alteration in oral biofilm structure when AgNPs were applied. Conclusions: AgNPs exhibited significant potential to limit oral bacterial proliferation from microbial biofilms while contributing to the maintenance of oral condition in individuals with MIDs.