Critical appraisal of systematic reviews of intervention in dentistry published between 2019-2020 using the AMSTAR 2 tool.

Introduction The number of systematic reviews (SRs) in dentistry published each year has grown considerably, and they have been essential in clinical decision-making and health policy.Objective The objective is to critically appraise SRs of intervention in dentistry using the 'A Measurement Tool to Assess Systematic Reviews 2' (AMSTAR 2) tool published within one year.Methods A search in the Medline/PubMed database was performed. The SRs were identified in two phases. The first phase identified SRs of interventions in dentistry by title and abstract. In the second phase, the full text was read, applying the eligibility criteria. Three calibrated reviewers methodologically assessed all SRs identified using the AMSTAR 2 tool. Data were analysed descriptively, and SRs were grouped according to methodological quality as moderate/high and low/critically low. A logistic regression model was applied to explore the associations between methodological quality and the study's characteristics.Results Two hundred and twenty-two SRs were included. The methodological quality of the SRs included in this study were: critically low (56.8%), low (27.9%), moderate (14.4%) and high (0.9%), according to AMSTAR 2. There were no statistical differences between moderate/high and low/critically low methodological quality and publication year, continent, journal Impact Factor and dental speciality.Conclusion Less than 1% of recently published SRs in dentistry were classified with high methodological quality. We hope that this study will alert researchers about the need to improve the methodological quality of SRs.

Evaluation of the genotoxic properties of nickel oxide nanoparticles in vitro and in vivo.

Nickel-based nanoparticles (NPs) are new products with an increasing number of industrial applications that were developed in recent years. NiO NPs are present in several nanotechnological industrial products, and the characterization of their genotoxic potential is essential. The present study assessed the genotoxicity of NiO NPs in vivo and in vitro using the somatic mutation and recombination test in somatic cells of Drosophila melanogaster (SMART), the cytokinesis - block micronucleus assay (CBMN), and the comet assay in a V79 cell line. The NiO NPs used in this study were about 30 nm in mean size. Larvae of Drosophila melanogaster were exposed to 5 mL of five different concentrations (1.31, 2.62, 5.25, 10.5, and 21 mg/mL) of NiO NPs. In turn, V79 cells were treated with a concentration range of 15-2000 µg/mL NiO NPs. The SMART showed that all concentrations of NiO NPs are genotoxic to the standart (ST) cross when compared to the negative control. On the other hand, only the highest concentration (21 mg/mL) was genotoxic to the HB cross. Somatic recombination was the preferential mechanism lesions were induced in D. melanogaster. The results show that NiO NPs were mutagenic to V79 cells as assessed by the CBMN assay. Significant differences in the frequencies of micronuclei (MN) were observed using the highest NiO NP concentrations (250 and 500 µg/mL) in the 4- and 24-h treatments, but when 125 µg/mL NiO NPs was used, such difference was observed only in the 4-h exposure time. The comet assay revealed that 62, 125, 250 and 500 µg/mL NiO NPs induced a significant increase in DNA damage. The results observed in this study indicate that NiO NPs are genotoxic and mutagenic in vitro and in vivo.