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Magister Scientiae Dentium - MSc(Dent) / Background: The primary goal of pulp therapy in the deciduous dentition is to keep the teeth fully functional in order to prevent arch space loss. A pulpectomy is a pulp therapy procedure indicated when an irreversibly inflamed or necrotic radicular pulp is encountered. ZOE and iodoform pastes (i.e. Kri 1 paste and Vitapex) have been recommended as root filling materials after pulpectomy. High clinical success rates have been reported with Vitapex and the fact that it resorbs readily when extruded beyond the apex is an added advantage. However, it has also been reported to resorb from within the root canals and even cause pathological root resorption in cases where the vital pulp is inflamed (Nurko et al., 2000). Iodoform-based preparations are thought to be more appropriate because they fulfill nearly all the requirements of the ideal root filling materials in primary teeth. Despite this, there are limited studies comparing the antibacterial effect of iodoform-based preparations. Aim: The aim of this study was to evaluate the antibacterial efficacy of Vitapex (V), Kri 1 paste (K) and pure iodoform (I) against E. faecalis.

Aboard the International Space Station, potable water will likely be produced from recycled wastewater. The National Aeronautic and Space Administration (NASA) plans to use iodine as a disinfectant, and, consequently, the formation of iodinated disinfection by-products (IDBPs) requires investigation. Objectives of this research were to determine possible precursors of IDBPs, identify IDBPs formed, and apply flavor profile analysis (FPA) as a tool to evaluate water qaulity. Experiments were performed by separately reacting iodine with each of the following organic compounds: methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, acetone, and formaldehyde. NASA previously identified all of these compounds in wastewater sources under consideration for recycling into potable water. Experiments were performed at pH 5.5 and 8, iodine concentrations of 10 and 50 mg/L, and organic concentrations of 5 and 50 mg/L. Gas chromatography/mass spectrometry was used to identify and monitor the concentrations of organic species. Spectrophotometry was used to monitor the iodine concentration. Acetone was the only compound identified as an IDBP precursor and it reacted to produce iodoacetone and iodoform. Concentrations of iodoform from 0.34 mg/L to 8.637 mg/L were produced at conditions that included each pH level, iodine concentration, and acetone concentration. The greatest iodoform concentration was produced at pH 8 from 50 mg/L of iodine and acetone. FPA indicated that the odor threshold concentration (OTC) of iodoform was 1.5 ug/L, and the OTC of iodine was 500 ug/L. Both iodine and iodoform have medicinal odors, making it difficult to distinguish each compound when present in a mixture. / Master of Science