en Oral medicine Oral medicine Original article Original article <div style="text-align: justify;"><span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Background and Aim</span></span></span></span></b><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">:</span></span></span></span></b> <span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana="">Green synthesis through using plants such as <i>Quercus infectoria (Q. infectoria)</i> is a relatively novel technique for synthesis of nanoparticles. This study aimed to assess the effect of silver nanoparticles (SNPs) green synthesized by using the <i>Q. infectoria</i> extract on some dental pathogens.</span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Materials and Methods: </span></span></span></span></b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana="">In this in vitro study, SNPs were synthesized by using the <i>Q. infectoria</i> extract and silver nitrate. Formation of SNPs was confirmed by UV-visible spectrophotometry. Presence/absence and proliferation of <i>Streptococcus mutans</i> (<i>S. mutans</i>), <i>Streptococcus salivarius</i> (<i>S. salivarius</i>), <i>Streptococcus sobrinus</i> (<i>S. sobrinus</i>), <i>Lactobacillus acidophilus (L. acidophilus)</i>, and <i>Enterococcus faecalis</i> (<i>E. faecalis</i>) were evaluated by observing the tube turbidity following their culture in presence of SNPs. Also, different concentrations of <i>Q. infectoria</i> extract (1, &frac12;, &frac14;, 1/8, and 1/16) were added to 5 bacterial plates, and the diameter of the growth inhibition zones was measured by a ruler. The results were reported descriptively.</span></span></span>&nbsp;</span></span></span><br> <span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Results: </span></span></span></span></b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#0e101a">The minimum inhibitory concentration (MIC) of SNPs against <i>L. acidophilus</i> was lower than that for other pathogens. The highest antibacterial effect was observed in concentration of 1 against <i>L. acidophilus</i>, and &frac12; on <i>S. salivarius</i> and <i>L. acidophilus</i>. Also, <i>L. acidophilus</i> was the most sensitive and <i>E. faecalis</i> was the least sensitive microorganism to &frac14;, 1/8, and 1/16 concentrations. The 1/16 concentration caused no growth inhibition zone in <i>E. faecalis</i> plate.</span></span></span></span><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:"Verdana",sans-serif"></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Conclusion:</span></span></span></span></b> <span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#0e101a">Green synthesized SNPs had acceptable antibacterial activity against the tested microorganisms, and may be used as an antibacterial agent against these pathogens.</span></span></span></span></span></span></span><br> &nbsp;</div> Silver, Nanoparticles, Anti-Bacterial Agents, Streptococcus mutans, Lactobacillus acidophilus 8 14 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-1347-1&slc_lang=en&sid=1 Bahareh Nazemi Salman dr.b.nazemi@gmail.com 100319475328460013918 0000000215456460 No Pediatric Dentistry, Dental School, Zanjan University of Medical sciences, Zanjan, Iran Negin Aliyari negin_aliyari@yahoo.com 100319475328460013919 0000000388919993 No Faculty of Dentistry, Zanjan University of Medical Sciences, Zanjan, Iran Alireza Yazdinezhad yazdinezhad@zums.ac.ir 100319475328460013920 0000000267761395 No Department of Pharmaceutical Biotechnology, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran Seyede Solmaz Taheri Solmaz.taheri.1990@gmail.com 100319475328460013921 0000000272378761 Yes Department of Biostatistics, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mahtab Mohammadi Qeydari mahtabmg@yahoo.com 100319475328460013922 0000000202894971 No Student Research Committee, Qazvin University of Medical Sciences, Qazvin, Iran