Comparative Evaluation of the Success Rate of Pulpotomy in Primary Molars Using Ferric Sulphate (FS) and Mineral Trioxide Aggregate (MTA): A Clinical and Radiographic Study

Purpose: The aim of this present study was to observe clinical, radiographic response of pulp to Ferric Sulphate and Mineral Trioxide Aggregate when used as pulpotomy agent in primary molars. Materials and Methods: Sixty restorable primary molars were selected for the study. The children were chosen who require minimum two pulpotomies in either arch preferably each on the opposite side (i.e. right and left). Primary molars on the right side of the patient were assigned to Ferric Sulphate (FS) (Group A) and left side was assigned for the Mineral Trioxide Aggregate (MTA) (Group B). Statistical analysis was done for pain, swelling, sinus, and fistula and for internal resorption, furcation radiolucency and periapical pathology using the chi-square test. Results: outcome of the present study was observed at 3 month interval and after 6 months. The clinical success rate for MTA (AQUA) and ferric sulphate during 3 and 6 month follow up was 100%. The radiographic follow up of MTA was 100% during 3 and 6 month, whereas it was 96.6% for 3 and 6 month follow up with respect to ferric sulphate. There were no significant differences in the clinical (p>0.1) and radiographic (p>0.98) success rates among both the groups. Conclusion: ferric sulphate was found to be equally effective when compared with MTA. Radiographic success rate was lower for Ferric sulphate (Group A) than that of MTA (Group B) with occurrence of one internal resorption seen with first primary molar.

Pulpotomy: Modern concepts and materials

Pulpotomy is one of the most common treatment modalities in pediatric dentistry where amputation of only coronal pulp is done. Radicular pulp remain untouched and treated with long term clinically successful medicaments such as formocresol, glutaraldehyde, ferric sulphate etc. The success of pulpotomy depends on assessment of the pulp and the technique. Due to the availability of newer material nowadays pulp regeneration can also be done.

Iron-Speciation Control of Chalcopyrite Dissolution from a Carbonatite Derived Concentrate with Acidic Ferric Sulphate Media

The mechanisms involved in the dissolution of chalcopyrite from a carbonatite concentrate in a ferric sulphate solution at pH 1.0, 1.5 and 1.8, and temperatures 25 °C and 50 °C were investigated. Contrary to expectations and thermodynamic predictions according to which low pH would favour high Cu dissolution, the opposite was observed. The dissolution was also highly correlated to the temperature. CuFeS2 phase dissolution produced intermediate Cu rich phases: CuS, Cu2S and Cu5FeS4, which appeared to envelop CuFeS2. Thermodynamic prediction revealed CuS to be refractory and could hinder dissolution. CuFeS2 phase solid-state dissolution process was further discussed. Free Fe3+ and its complexes (Fe(HSO4)2+, Fe(SO4)2– and FeSO4+ were responsible for Cu dissolution, which increased with increasing pH and temperature. The dissolution improved at pH 1.8 rather than 1.0 due to the increase of (Fe(HSO4)2+, Fe(SO4)2– and FeSO4+, which were also the predominating species at a higher temperature. The fast and linear first dissolution stage was attributed to the combined effect of Fe3+ and its complex (Fe(HSO4)2+, while Fe(SO4)2– was the main species for the second Cu dissolution stage characterised by a slow rate.

Ferric sulphate flocculation as a concentration method for Giardia and Cryptosporidium in filter backwash water

Filter backwash water (FBW) is a prominent residue from water treatment plants (WTPs) that is often disposed into water bodies or recycled within the WTP without due disinfection. FBW usually contains particles within a size range that includes pathogenic protozoa, as the infective forms of Giardia and Cryptosporidium, parasites responsible for waterborne diseases outbreaks. Quantifying (oo)cysts is essential for addressing this matter, as it might assist research on giardiasis and cryptosporidiosis epidemiology, as well as shed light onto disinfection technologies for FBW. However, (oo)cyst recovery from FBW and other complex matrices still lacks a standard protocol and entails specialized professionals and expensive material. Seeking to provide insight in a reduced-cost recovery method, this study analysed the recovery efficiency (RE) obtained by acid flocculation with ferric sulphate, a common coagulant, on bench-scale simulated FBW. Steps included concentration by flocculation, centrifugation, and quantification by immunofluorescence. Although recovery was sufficient for Cryptosporidium parvum (40.59%), Method 1623.1 recommendations were not reached for Giardia muris (1.76%). Coefficients of variation obtained for both organisms were not satisfactory, highlighting the variability to which environmental matrices are subjected and why defining a methodology for (oo)cyst recovery in WTP residues is important.

Preparation of polymeric aluminum ferric sulphate from waste residue of aluminum industry

Polymeric aluminum ferric sulphate(PAFS) was prepared from high-sulfur bauxite flotation tailings and red mud by roasting, acid leaching and polymerization. The effects of leaching temperature, leaching time, liquid-solid ratio on the leaching rate of Al3+ and Fe3+were investigated. The optimal leaching conditions are as follows: leaching temperature 100℃, leaching time 90 min, sulfuric acid concentration 4.5mol/L and liquid-solid ratio 5 mg/L. Infrared spectroscopy and X-ray diffraction analysis was carried out on the PAFS prepared under the optimum process parameters. The characterization of PAFS shows that the synthesized PAFS had polymeric aluminum, iron and hydroxyl structures. Wastewater disposal test of synthetic PAFS shows that the removal rates of COD, turbidity and chromaticity are 45.61%, 75% and 94.18%, respectively.

Assessment of the Effects of Sugarcane Straw Addition to the Flocculation/Coagulation Process on Vinasse Concentration

Vinasse is the main by-product of ethanol production. In 2005, its application was regulated in the state of Sao Paulo, so if it is to be applied to the fields, its volume must meet the established concentration regulations. Straw contains one-third of sugarcane calorific value and can be used for cogeneration. For these purposes, the project objective was to assess the effects of straw on the concentration of vinasse solids through physical and chemical processes, so its concentrated form could be used as biomass for cogeneration. For that, different concentrations of straw, ferric sulphate, and ferric chloride were used. Turbidity reduction was the parameter analysed. Both reagents were effective in reducing the turbidity. The 200 ppm of ferric chloride and 0.25% straw content reduced the turbidity by 55.02% and 400 ppm of ferric sulphate and 0.25% of straw reduced it by 57.96%. The addition of straw showed no significant effect in terms of the turbidity reduction, however, both best treatments had 0.25% straw content addition in it. Straw can be used to concentrate vinasse, contributing to the efficiency of the process and increasing the energy potential of the concentrated solids.