Efficacy of 30% and 38% Silver Diamine Fluoride in Arresting Caries Lesions After Different Application Times: An in Vitro Study

Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.

Synthesis, spectroscopic and crystal structure studies of N,N'-Bis [2-hydroxy-3-methoxybenzylidene] diaminobenzene derivatives

The reaction of 0-vanillin 1 with phenylenediamine isomers 2-4 in dichloromethane formed three diaminobenzene derivatives: N,N'-bis [2-hydroxy-3-methoxybenzylidene]-1,2-diaminobenzene 5, N,N'-bis [2-hydroxy-3-methoxybenzylid-ene]-l,3-diaminobenzene 6 and N,N'-bis [2-hydroxy-3-methoxybenzylidene]-l,4-di-aminobenzene 7, respectively, All compounds were obtained as single crystals and the structures were determined by X-ray crystallography. All compounds were confirmed by FTIR, HRMS, ID and 2D NMR spectroscopy. The complete assignments of these compounds, using ID and 2D NMR including APT, DEPT-135, COSY, HMQC and HMBC in CDC1[3], will be discussed

Complexes of some 3d metal ions with propylenediamine bis [isatin] schiff base ligand

Metal chelates of dichlorides, trichlorides and acetates of Ni[II], Co[II], Cu[II], Cr[III], Fe[III] and Mn[II] with propylenediamine bis [isatin] Schiff base lig and were prepared and characterized by analytical, conductivity, magnetic, PMR, IR and electronic spectral data. The lig and acted either as neutral or dibasic ONNO quadridentate yielding cationic or neutral complexes. Magnetic and spectral data have suggested square planar structure for Ni[II] and Co[II] neutral chelates. The data also suggested octahedral structure for Mn[II], Fe[III], Cr[III], Co[II] and Ni[II] cationic complexes and a dimeric penta-coordinate structure for Cu[II] chelate