Effect of Potassium Iodide on the Tensile Bond Strength of Glass Ionomer Cement and Resin Modified Glass Ionomer Cement on Silver Diamine Fluoride treated Dentine: A Comparative in Vitro study

AIM OF THE STUDY: Silver Diamine Fluoride (SDF) promotes remineralization, inhibits demineralization, increases dentin hardness and outperforms in bactericidal effect. A significant disadvantage of SDF is the unaesthetic permanent black staining of teeth caused by silver oxide. The black staining caused by SDF can be overcome by the use of Potassium iodide (KI). However, the influence of potassium iodide on the bond strength of SDF to restorative materials has no enough documentation. Hence this study was designed to estimate the effect of SDF/KI on the tensile bond strengths of restorative materials - glass ionomer cement (GIC) and resin- modified glass ionomer cement (RMGIC). METHODS: A total of 120 samples were used in the study. The occlusal surfaces were ground and polished using 600 grit silicon carbide abrasive paper under running water and embedded in self cure acrylic blocks. A hollow polyvinyl mould is placed on treated surface. Specimens were randomly divided into two groups (A, B) with 60 samples each. This in turn sub grouped to three subgroups each (A1, A2, A3 and B1, B2, B3) with twenty samples each. Subgroup A1 was conditioned with10% Polyacrylic acid (GC Dentin conditioner, GC Corp, Japan), rinsed, treated with 38% SDF (Fagamin) for ten seconds, rinsed, and then filled with GIC(GC IX, GC Corp, Tokyo, Japan). A 26 gauge ligature wire was twisted to form a loop at one end and placed inside the setting cement. Subgroup A2 was conditioned with10% Polyacrylic acid, rinsed, treated with 38% SDF for ten seconds, followed by potassium iodide (KI). On obtaining a creamy white precipitate it’s washed off and filled with GIC with the looped ligature wire. Subgroup A3 was conditioned with 10% Polyacrylic acid, rinsed and restored with GIC with the wire. Same procedure was followed for all subgroups in group B except that the restorative material here was RMGIC (GC II LC, GC Corp, Japan) and light cured at 400 nm/20 seconds. After complete setting the moulds were removed. All samples were tested for tensile bond strength by mounting onto the Universal Testing Machine running at a crosshead speed of 5mm/minute. RESULTS: The tensile bond strength of glass ionomer cement to dentin compared with the tensile bond strength of SDF followed by glass ionomer cement to dentin the P value was non significant (0.77). The comparison of tensile bond strength of resin- modified glass ionomer cement to dentin, to SDF followed by resin-modified glass ionomer cement to dentin was not statistically significant. (P-0.35). The P value for comparison of SDF treated glass ionomer cement was not significant to SDF/KI followed by GIC (P value - 0.23). Similarly the comparison of SDF treated resin modified glass ionomer cement was not significant to SDF/KI followed by RMGIC (P value - 0.46). On comparing the tensile bond strength of glass ionomer cement to dentin to tensile bond strength of resin-modified glass ionomer cement to dentin the mean difference was statistically significant (P < 0.001). CONCLUSION: Silver diamine fluoride does not affect the tensile bond strength of glass ionomer cement and resin-modified glass ionomer cement to dentin. Potassium iodide does not influence the tensile bond strength of glass ionomer cement and resin-modified glass ionomer cement on silver diamine fluoride treated dentin. Resin modified glass ionomer cement has higher tensile bond strength than glass ionomer cement and the choice of restorative material relies on the clinician’s choice based on individualized patient’s treatment needs

Immune indices and identical functions of two prophenoloxidases from the haemolymph of green tiger shrimp Penaeus semisulcatus and its antibiofilm activity

In the present study, we purified two prophenoloxidases (proPO) from haemolymph of green tigershrimp,Penaeus semisulcatusby gel fermentation chromatography using blue Sepharose matrix. The twopurified prophenoloxidase macromolecules are of about 76 and 75 kDa determined through SDS-PAGEand named asPenaeus semisulcatusprophenoloxidase I (PSproPO I) andPenaeus semisulcatusproph-enoloxidase II (PSproPO II). It was further characterized by X-Ray Diffraction (XRD), Fourier TransformInfrared Spectroscopy (FTIR), Circular Dichroism (CD) and High Performance Liquid Chromatography(HPLC) analysis. The purified PSproPO I and PSproPO II showed the strongest agglutination titre againsthuman erythrocytes compared to goat RBC. The PSproPO I and PSproPO II showed phagocytic activityagainst yeastSaccharomyces cerevisiaeand encapsulation activity against Sepharose CL 6B beadscompared to CM Sepharose and Sodium alginate beads. The functional analysis of purified PSproPO I andPSproPO II showed enhanced PO activity when added with the triggering molecules such as pathogenassociated molecular patterns (PAMPs), metals and chemicals. In addition, eluted fraction containingPSproPO I and PSproPO II showed antibiofilm activity against Gram positive and Gram negative bacteria.The above results concluded that no significant differences were found between the purified PSproPO Iand PSproPO II immune indices and functions. This study might provide a sensitive platform to under-stand more about the critical roles of PSproPO I and PSproPO II in crustacean immune syste

Chromogenic polyaniline picrate- A novel sorbent for selectivity of anions in potassium and sodium salts

104-113<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">A novel chromogenic, polymeric sorbent material Polyaniline picrate (PANIPI) has been synthesized by chemical oxidative polymerization and characterized using various spectral techniques. Cyclic voltammetry and four probe conductivity measurements have revealed that the polymer is highly electroactive. Surface morphology is analyzed using SEM and TEM micrographs. Potassium halides, potassium sulphate and potassium thiocyanate are used as sorbate materials for ion exchange on PANIPI. Five types of sorption isotherms namely Langmuir, Freundlich, Dubinin-Radushkevich, Temkin and Redlich-Peterson are applied to the sorption process. Among these isotherms Langmuir, Freundlich and Temkin models fitted well for the sorption of potassium salts on PANIPI. The maximum adsorption capacity (qm) follows the size order of anions. The intensity of FT-IR stretching vibration for SCN- at 2066 cm-1 varies linearly with concentration, making PANIPI an effective sensor material for the quantitative determination of SCN-. The potassium to sodium selectivity of 2:1 is observed at both low and high sorbate concentrations.</span