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BackgroundAlthough, mineral trioxide aggregate (MTA) and new experimental cement (CEM) are good root filling cements, but had no or low antimicrobial activities. The aim of this study was to evaluate the effects of addition of silver nanoparticles (SNP) to these two cements on antimicrobial effects against five most dental infection related microorganisms.Material and MethodsTwo suspensions of 100 and 200 ppm of SNP were prepared and 180 μl of microbial suspension with 1.5 × 108 CFU/ml of each respected microorganisms were re-suspended in deionized water or each of SNP suspensions. After that, 60 μg of MTA and CEM were added to each tube. In one tube, the mixture of all above mentioned microorganisms were added as a source of microorganism. Colonies were counted after 0, 24, 48, 72 and 96 hours intervals of incubation at 35°C on blood agar for evaluation of antimicrobial efficacy.ResultsMTA and CEM had antibacterial activities on all microorganisms’ strains except for Enterococcus faecalis and mixture group. MTA had better antibacterial activity than CEM but the difference was not significant (p<0.05). The combination of SNP with two cements resulted in significantly higher antimicrobial activities (p<0.05). Also, there was no statistically significant difference between two SNP concentrations (p>0.05).ConclusionsMixture of MTA and CEM with different concentrations of SNP significantly increased the antibacterial activity. Key words:Mineral trioxide aggregate, calcium-enriched mixture, silver nanoparticle, antimicrobial activity.

Orthodontic archwires, especially nickel-titanium (NiTi) ones, are a major source of nickel release. Despite their importance, no in vivo studies have assessed the ion release from conventional or new generations of NiTi archwires (copper-included and epoxy-coated). This double-blind parallel randomized clinical trial was done on 84 saliva specimens sampled at two time points from 42 orthodontic patients. The patients were randomly divided into three groups of NiTi, copper NiTi (NiTiCu), and epoxy NiTi archwires (n = 14 each). The effects of 2-month treatment, wire types, gender, and age on pretreatment, posttreatment, and time-dependent differences were analyzed statistically (α = 0.05). Salivary nickel concentrations were 10.4571 ± 0.77168 and 11.0779 ± 0.81232 μg/L, respectively, in the baseline and second month. This increase was significant (P = 0.0000, paired t test). The extents of nickel increase in different groups were 0.8279 ± 0.14 (NiTi), 0.6493 ± 0.10 (NiTiCu), and 0.385 ± 0.11 (epoxy-coated NiTi) μg/L (P = 0.0000, one-way analyses of variance (ANOVA)). Differences between each two archwire types were significant (P = 0.000, Tukey). Age and gender did not play a role. It can be concluded that NiTi archwires might increase nickel salivary levels. Epoxy-coated NiTi followed by copper NiTi archwires might release less nickel compared to conventional NiTi ones.

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Background: Different studies about the effects of mouthwashes on force reduction by elastomeric chains are reported in the literature. Hence, this review was done for the assessment of force degradation in the elastomeric chains in different mouthwash compositions. This study helps to improve the clinical performance of elastomeric chains used in orthodontics, reducing force degradation, and finally assisting clinicians in choosing better and more efficient methods for their treatments. Materials and Methods: In this review article, an extensive search was performed in the electronic databases of Cochrane Library, Web of Science, PubMed, and Scopus from the year 1990–2020. No language restriction was considered and manually investigated the reference lists of all articles related to the title. Out of 450 obtained articles, 14 in vitro studies were chosen based on the inclusion criteria, and their quality was assessed using modified CONSORT. This systematic review was limited and written based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Results: Based on the results achieved, mouthwashes containing alcohol caused considerable force degradation in the elastomeric chains compared to the alcohol-free ones and mouthwashes with fluoride caused lesser force degradation compared to other types.