Evaluation of the cell viability and antimicrobial effects of orthodontic bands coated with silver or zinc oxide nanoparticles: An in vitro study / 대한치과교정학회지

Objective@#We aimed to evaluate the cell viability and antimicrobial effects of orthodontic bands coated with silver or zinc oxide nanoparticles (nanoAg and nano-ZnO, respectively). @*Methods@#In this experimental study, 30 orthodontic bands were divided into three groups (n = 10 each): control (uncoated band), Ag (silver-coated band), and ZnO (zinc oxide-coated band). The electrostatic spray-assisted vapor deposition method was used to coat orthodontic bands with nano-Ag or nano-ZnO. The biofilm inhibition test was used to assess the antimicrobial effectiveness of nano-Ag and nano-ZnO against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Biocompatibility tests were conducted using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The groups were compared using oneway analysis of variance with a post-hoc test. @*Results@#The Ag group showed a significantly higher reduction in the number of L. acidophilus, C. albicans, and S.mutans colonies than the ZnO group (p = 0.015, 0.003, and 0.005, respectively). Compared with the control group, the Ag group showed a 2-log 10 reduction in all the microorganisms' replication ability, but only S. mutants showed a 2-log10 reduction in replication ability in the ZnO group. The lowest mean cell viability was observed in the Ag group, but the difference between the groups was insignificant (p > 0.05). @*Conclusions@#Coating orthodontic bands with nanoZnO or nano-Ag induced antimicrobial effects against oral pathogens. Among the nanoparticles, nano-Ag showed the best antimicrobial activity and nanoZnO showed the highest biocompatibility.

Detection of Mycobacterium tuberculosis complex by gyrB PCR in patients with clinical suspicious of tuberculosis in Mazandaran, Iran

Introduction: Mycobacterium tuberculosis complex [MTBC] are causative agents of human and animal tuberculosis. Differentiation of MTBC members is required for appropriate treatment of individual patients and for epidemiological purposes and reduction in drug resistances. Material and Methods: 1345 patients were collected with clinical suspicions of tuberculosis who referred to the Health Care Center of Mazandaran province from July 2010 to June 2011. The specimens were stained by the Ziehl-Neelsen staining technique and were cultured on Lowenstein-Jensen medium to detect the mycobacteria. For recognition of Mycobacterium tuberculosis complex MTUB-f and MTUB-r primer [gyrB-PCR1] were used. For differentiation of Mycobacterium tuberculosis complex members MTUB-756-Gf and MTUB- 1450Cr [gyrB-PCR2] and RFLP PCR using RsaI restriction enzymewere used. Results: Of 1345 specimens, only 65[4.83%] isolates were positive culture of which59 [90.76%] were MTBC and 6 [9.24%] identified as Mycobacteria other than tuberculosis. All of 59 isolates were M. tuberculosis. Conclusion: The gyrB-RFLP PCR and using the RsaI restriction enzyme is a rapid and easy technique to perform for differentiation of the member of M. tuberculosis complex. Key words: gyrB- RFLP PCR- RsaI - Mycobacterium tuberculosis complex