Evaluation of Anti-biofilm Activity of Silica nanoparticles against dental Streptococcus mutans: In-Vitro Study

Abstract

Background: Dental caries is a prevalent chronic infection caused by cariogenic bacteria that cling to teeth, mainly Streptococcus mutans. These bacteria break down sugars into acid over time, demineralizing the tooth structure. Biofilm as an early colonizer and is the most important bacterium in the formation of dental caries . Materials and Methods: The present study concentrates on isolation and identification of the S.mutans pathogen from patients suffering from dental caries. On specific media, the isolates were cultivated. From human teeth, one hundred dental caries samples are gathered. Using MS-agar (Mitis Salivarius agar), only fifty samples are regarded as positive bacterial isolates to identify the S.mutans isolates, their morphological, cultural, biochemical, and VITEK features were examined. . The microtiter plate method was used to detect the development of biofilms by comparing the characteristics of the isolates. In this work, the median values of optical density (OD) at 630 nm were utilised to employ ELISA to distinguish between S. mutans isolates that developed biofilms and those that did not. To confirm the type of bacteria using molecular identification. Objectives: The purpose of this work is to determine the subminimum and minimum inhibitory concentrations of silica nanoparticles that function as anti-biofilm agents, as they have an impact on bacterial growth and details of silica nanoparticle characterization. Results: In this study considered to be S.mutans are twenty isolates the morphological, cultural, biochemical, and VITEK properties of the bacterial isolates were used to identify them . in this study molecular identification to more confirm of S.mutans the result of PCR showed that 20/20(100%) isolates were PCR positive for 16r RNA gene . in this investigation different isolates were evaluated for their capacity to create biofilm; nine (45%) were judged to be strong producers, seven (35%), to be moderate producers, and four (20%) to be weak producers. the sol-gel method was used in this study to synthesis silica nanoparticles, which were then characterised by XRD, FE-SEM, EDX, and TEM. In this study, Si-NPs were tested against isolates of S.mutans by using a resazurin mediated microtiter plate the results have shown that silica nanoparticles has inhibitory action (MIC) against S. mutans with concentration 0,78 mg/ml and sub-MIC with concentration 0.39 mg/ml. .The anti-biofilm effect of silica nanoparticles on isolates of S. mutans in the current investigation revealed that the biofilm mean of control (biofilm development without silica nanoparticles) was 0.583, whereas the findings for anti-biofilm utilizing sub-MIC of NPs, was 0.185 in microtiter plate method when the (p value) less than 0.05 this proves the NPs effected on the biofilm formation by S.murans and inhibition it . Conclusion: Silica nanoparticles' anti-biofilm action on S.mutans isolates demonstrated the importance of biofilm inhibition.