5.1. Application of Silver Nanoparticles in Dental Medicine

Silver has been used in dentistry for over a century and is a crucial component in dental amalgam fillings [4]. It is used in reconstructive dentistry, as well as in implantology and the production of dentures. Biofilms on the surface of a dental implant can cause inflammatory lesions on the peri-implant mucosa, consequently increasing the risk of implant failure [13]. The main goal of using silver nanoparticles is to prevent infection during and after dental surgery, i.e., thanks to their antibacterial activity, microbial colonization through embedded biomaterials are reduced [4,38,39].

The antimicrobial features of silver nanoparticles have also been studied in detail in dental medicine. Based on the results of the research, there is a growing interest in AgNPs [40]. The oral cavity is an active ecosystem that is regularly colonized by diverse pathogenic microorganisms, so dental materials and implants have an increased risk of infection [13]. In vitro examinations show the unique antimicrobial silver nanoparticles’ action when bound to dental materials such as nanocomposites, acrylic resins, composite resins, adhesives, intracanal drugs and implant coatings [40]. They are also used to make membranes for guided tissue regeneration in periodontal treatment [6]. Smaller silver nanoparticles have increased antibacterial activity against oral anaerobic pathogenic bacteria [6]. It is important to note that AgNPs, thanks to their antitumor properties, have shown positive results in the treatment of oral cancer [40].

The application of silver preparations as a microbicide to stop dentin caries is becoming more common. In vitro experiments demonstrated the microbicidal effectiveness of silver diamine fluoride (SDF) on cariogenic microbes in a human dentin model. Besides, silver nanoparticles have also been recognized in in vitro studies to have a microbicidal impact against growth, adhesion, and biofilm development of Streptococcus mutans in human dentin models. SDF has an intense antimicrobial effect on dental plaque. It reduces the metabolism of carbohydrates in dental plaque and stimulates a different balance of plaque flora [41,42].

SDF has a bactericidal effect on cariogenic bacteria, largely S. mutans, inhibiting the increase in cariogenic biofilms on teeth. Additionally, SDF stimulates remineralization of demineralized enamel or dentin and inhibits collagenases (matrix metalloproteinases and cysteine cathepsins) and thus protects the collagen in dentin from demolition [43].

AgNPs, in combination with antibiotics, enhances bactericidal features. When inactive antibiotics are combined with AgNPs, they gain strong antibacterial activity against multidrug-resistant strains of bacteria [6].

Silver nanoparticles have a better bacteriostatic and bactericidal outcome, with five times lower concentration than chlorhexidine. When AgNPs are used in the proper concentration, it is a safe option than other chemically derived antimicrobials [44]. Dental materials with AgNPs are biocompatible and have no meaningful toxic or mutagenic consequences [6].


IADR Abstract Archives Evaluation of the Antimicrobial Activity of Colloidal Silver in Odontopathogenic Bacteria Objectives: Determine the antimicrobial activity of colloidal silver in three oral bacteria. Methods: Enterococcus faecalis (ATCC 29212), Fusobacterium nucleatum (ATCC 10953) and Streptococcus mutans (ATCC UA159) were obtained from the American Type Culture Collection. The minimal inhibitory concentration (MIC) was performed in 96-well flatbottom plates containing 100μL of Colloidal Silver at 20 ppm in TSB supplemented with 10% FBS and 100 μL of 1.0 × 108 CFU / mL of bacterial strains, up to a final volume of 200μL per well; 5μg / mL chlorhexidine was used as a positive control for inhibition of bacterial growth and saline solution (SS) as a negative control. The plates were incubated at 37 ° C for 72h in a microaerobic atmosphere. Subsequently, the percentage of growth inhibition was calculated using the MIC value. Finally, 10 μL of culture were taken from wells without bacterial strains growth and spread on TSA supplemented with 5% DSB. The CFU were counted after seven days of incubation. The minimum bacterial concentration (MBC) value was established as the low-est concentration of colloidal silver that killed the bacterial strains. Data were evaluated using t-student and ANOVA in SPSS v.21 Results: The data obtained show that the antimicrobial activity of the colloidal silver of 20 ppm was 99.9% and therefore showed no microbial growth for the bacterial strains evaluated compared to the control group of chlorhexidine. A statistically significant difference was observed (p< 0.05) between the groups evaluated. Conclusions: Colloidal silver at a concentration of 20 ppm has antimicrobial activity against odontopathogenic bacteria and could therefore be used as an antimicrobial in the oral cavity. Division: IADR/AADR/CA