Browsing by Author "Basson, Nicolaas"

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    Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms
    (BioMed Central, 2008) Basson, Nicolaas; Grobler, Sias Renier
    Background: Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict. With this in mind we tested the antimicrobial activity of honeys produced from plants grown in South Africa for their antibacterial properties on selected standard strains of oral microorganisms. Methods: The honeys used were produced from the blossoms of Eucalyptus cladocalyx (Bluegum) trees, an indigenous South African plant Leucospermum cordifolium (Pincushion), a mixture of wild heather shrubs, mainly Erica species (Fynbos) and a Leptospermum scoparium (Manuka) honey. Only pure honey which had not been heated was used. The honeys were tested for their antimicrobial properties with a broth dilution method. Results: Although the honeys produced some inhibitory effect on the growth of the microorganisms, no exceptionally high activity occurred in the South African honeys. The carbohydrate concentration plays a key role in the antimicrobial activity of the honeys above 25%. However, these honeys do contain other antimicrobial properties that are effective against certain bacterial species at concentrations well below the hypertonic sugar concentration. The yeast C. albicans was more resistant to the honeys than the bacteria. The species S. anginosus and S. oralis were more sensitive to the honeys than the other test bacteria. Conclusion: The honeys produced from indigenous wild flowers from South Africa had no exceptionally high activity that could afford medical grade status.
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    Evaluation of sterilising methods for re-implantation of orthodontic mini-implants
    (The University of the Western Cape, 2017) di Pasquale, Taryn; Harris, Angela; Basson, Nicolaas
    Re-implantation of mini-implants would be financially advantageous in orthodontics and could encourage an increase in use of these devices. An analysis of the bacterial contamination after different sterilising methods has currently not been performed. The aim of this study was to determine the most effective method in sterilising of orthodontic mini-implants for re-implantation in the same patient. The sample included 40 retrieved mini-implants which were collected from private orthodontists, orthodontic registrars, and a maxillo-facial and oral surgeon in South Africa after completed use in patients. They were allocated into groups that underwent different sterilising processes. Gr1 was autoclaved; Gr2 was immersed in 37% phosphoric acid for 10 minutes, followed by being soaked in Milton for 30 minutes; Gr3 was dipped in 70% ethanol and then flamed in a butane gas burner; and GrC did not undergo any processing and served as the control. Bacteria remaining after processing were cultured in Brain Heart Infusion Medium and incubated at 37 degrees Celsius to determine whether any bacterial contamination remained on the mini-implant. To investigate the effects of the sterilising methods on the surface of the mini-implants, they then underwent scanning electron microscopy analysis to assess amount of visible tissue remnants which remained on the surface. These miniimplants were further subjected to energy dispersive spectroscopy (EDS) to investigate their elemental composition. All processing methods were able to sterilise the mini-implants tested and no bacterial growth was present after culturing in Brain Heart Infusion Medium. There were, however, differences in their surface appearances. Gr2 displayed the least amount remaining surface remnants (mean 5.21%), whereas Gr1 (autoclave) and Gr3 (burnt) showed mean of 30.08 and 47.04% tissue remnants on their surfaces respectively. Titanium, aluminium, vanadium, carbon and oxygen were found on all surfaces of the groups. Additional elements, namely, calcium, potassium, sodium, phosphorous, sulphur, silicon, bromine, chlorine, nitrogen, and magnesium were found in the tissue remnants of all the processing groups. Sterilising methods autoclave and burning (Gr1 and Gr3), which made use of heat, had almost double the atomic percentage of carbon. Gr2, etch and Milton, had the lowest atomic percentage of calcium and none of the mini-implants in this group showed traces of iron, which was present in the other groups. Based on the methods tested in this study, Gr2 which involves immersing the mini-implant in 37% phosphoric acid for 10 minutes, followed by soaking mini-implant in Milton for 30 minutes is the suggested method of sterilising mini-implants before re-implantation. Further studies looking into additional sterilisation methods, possibly with the use of sonication or scrubbing, are required to draw up protocols on reimplantation of mini-implants. Additional histological and ion release tests will also be required to confirm which method of sterilisation will result in no additional complications in the patient to that of insertion of a new, unused mini-implant.
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    In vitro antimicrobial comparison of three commercially available chlorhexidine-based oral rinses
    (South African Dental Association, 2016) Abdalrahman, Basheer Mohamed; Holmes, Haly; Peck, Mogammad T.; Basson, Nicolaas
    INTRODUCTION: Commercially available chlorhexidine (CHX) formulations differ in their CHX concentrations (0.2% and 0.12%) as well as in various additives including alcohol, antimicrobials such as cetylpyridinium chloride and antidiscolouration chemicals such as ascorbic acid and sodium metabisulphite. AIMS AND OBJECTIVES: To compare in vitro the antimicrobial efficacies of three different CHX preparations (Corsodyl ®, Curasept® and GUM® Paroex®) using 0.2% and 0.12% CHX concentrations as controls METHODS: A disk diffusion test was performed using pure cultures of the organisms Streptococcus mutans and Candida albicans, and mixed cultures (facultative and strict anaerobes) prepared from oral rinse samples of 14 study participants. The means and standard deviations of the diameters of inhibition zones were calculated. RESULTS: A statistically significant difference (p value = 0.0001) was found only in Candida albicans cultures between the mean inhibition zones of the CHX preparation disks. Pure CHX preparations and Corsodyl® showed higher antifungal efficacy than Curasept® and GUM® Paroex Conclusion: Both CHX preparations (0.12% and 0.2%) and the 0.2% CHX preparation containing alcohol (Corsodyl®) have more potent antifungal properties against C. albicans than alcohol-free 0.12% CHX preparations such as Curasept® and GUM® Paroex®.