Cytotoxicity of three light-cured resin cements on 3T3 fibroblasts

Abstract Introduction Light-cured resin cements are the first choice for the cementation of laminate veneers. Ideally, they should be biocompatible and offer minimum risks to patients. Objective The aim of this study was to evaluate, in vitro, the cytotoxicity of three resin cements: Variolink II, Ivoclar Vivadent (C1), Allcem Veneer, FGM (C2), and Rely X Veneer, 3M ESPE (C3). Material and method Twenty four samples of each of the cements were fabricated in a standardized metal mold, light activated, and transferred to a 96-well cell plate with culture of fibroblasts. After 24, 48, and 72h of incubation, cytotoxicity was assessed and cell viability was calculated by the methyl-thiazol-tetrazolium (MTT) colorimetric assay. Absorbance was measured at 570 nm using a microplate spectrophotometer. Result The following results were found: Variolink II presented viability of 72.24% (SD 6.80) after 24h, 83.92% (SD 5.26) after 48h, and 92.77% (SD 5.59) after 72h; Allcem Veneer exhibited viability of 70.46% (SD 12.91) after 24h, 85.03% (SD 21.4) after 48h, and 70.46% (SD 12.91) after 72h; Rely X Veneer showed viability of 5.06% (SD 0.88) after 24h, 5.84% (SD 1.18) after 48h, and 6.99% (SD 1.34) after 72h. Conclusion Under these testing conditions, Rely X Veneer presented significantly higher cytotoxicity compared with those of the other light-cured resin cements assessed

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia.

This is the author accepted manuscript. The final version is available from the American Association for the Advancement of Science via the DOI in this recordData and materials availability: Data from publicly available sources are cited in the supplementary materials. Other data and computer codes used in the analysis are publicly available at Zenodo repositoryIndigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)National Council for Scientific and Technological Development (CNPQ)National Council for Scientific and Technological Development (CNPQ)National Council for Scientific and Technological Development (CNPQ)European Research CouncilSão Paulo Research Foundation (FAPESP)Amazon FundSão Paulo Research Foundation (FAPESP)PVEMEC/MCTI/CAPES/CNPq/FAPEuropean Union’s Horizon 2020European Union’s Horizon 2020CAPESANRMCT/CNPq/CT-INFRA/GEOMAMCT/CNPq/CT-INFRA/GEOMACAPES/PDSECAPES/FapespaCNPqFAPESPCNPq/CAPES/FAPS/BC-NewtonFAPEMATRoyal Society GCRF International Collaboration AwardNSF/DEBCNPQ/PQNatural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Gordon and Betty Moore Foundatio