Browsing by Author "Mulder, R."

Now showing 1 - 3 of 3
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    An in vitro comparison of the marginal adaptation and discrepancy of stainless steel crowns
    (University of the Western Cape, 2018) Medhat, Rasha Mahmood Abdelrahman; Mulder, R.
    The benefits of restorative treatment are to remove cavities or defects, to restore function, maintain the arch integrity and to eliminate the progression of dental caries. The complexity of restorative treatment increases when the dental caries involves more than one surface of the tooth. Stainless steel crowns are considered to be the gold standard for multisurface carious lesions in primary teeth. Despite the high success rate and cost-effectiveness of stainless steel crowns compared to other restorations, failure of stainless steel crowns were reported in some cases. The major causes of failure of stainless steel crowns are poor marginal adaptation and marginal discrepancy.
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    The Photobiomodulation Effect of 940nm Laser Irradiation on Enterococcus faecalis in Human Root Dentin Slices of Varying Thicknesses
    (SBMU Journals, 2021) Mulder, R.; Sher, B.; Gutknecht, N.
    The main etiological factor of pulpal and periapical infections is the invasion of bacteria into the pulpal and endodontic systems.1 Successful treatment of these infections would require the removal and/or destruction of these microorganisms and create an effective coronal and apical seal to prohibit the reinfection of bacteria and influx of nutrients into the endodontic system. The ability of bacteria to penetrate deep into the dentin tubules and to form biofilms as well as the adhesion of certain bacteria to the dentin walls makes the destruction and removal of bacteria from the three-dimensional dentinal network a challenging task.2,3 Due to the complexity of this network, about 30%-45% of the root canal system escapes chemo-mechanical instrumentation4 as per the normal endodontic procedure with the dentist. Lasers have been used as an additional step to kill bacteria that could not be reached by chemo-mechanical instrumentation. Studies show that in favourable conditions, bacteria can penetrate to a depth of more than 1000 μm into the dentinal tubules.2 Numerous previous studies have been conducted to evaluate the bactericidal effect of various wavelengths of lasers, but most of these studies were conducted on dentine slices of 100, 300, 500, and 1000 μm.5-7 They were conducted with dentine samples up to 1000 μm, therefore limiting our understanding as to the effects of lasers and biocides, with one study beyond 2000 μm.8 This in vitro study aimed to compare the photobiomodulation effect of a 940 nm laser on Enterococcus faecalis through varying thicknesses of human root dentin slices.
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    The use of a digitally pulsed, high power diode laser for the treatment of physiological gingival pigmentation
    (The South African Dental Association, 2018) Booley, A-B; Peerbhay, F.; Mulder, R.; Mulder-van Staden, S.
    Gingival pigmentation, whether focal or diffuse, may be of aesthetic concern to patients. Establishing the underlying aetiology of the pigmentation is essential to ensure that the correct management is performed. Oral pigmentation is relatively common and can have a variety of clinical presentations. The characteristics of the pigmentation such as the location, colour, distribution, duration, surface characteristics and presence of cutaneous lesions are important features to consider in reaching a diagnosis. Investigation of the patient's dental, medical, familial histories and social habits are factors to consider. Possible aetiologies of oral pigmentation include traumatic, reactive, exogenous foreign bodies, drug-induced, neoplastic, genetic dysfunction and systemic disease associations. A biopsy and laboratory studies are often required to reach a definitive diagnosis. Pigmented lesions that have a recent onset, have increased in size or cannot be explained by local factors require a biopsy to establish a diagnosis. Physiological oral pigmentation is associated with an Increase in melanocyte activity, not an increase in melanocyte number. Melanocytes are specialized, unicellular, dendritic, melanin- producing cells derived from the neural crest during embryogenesis. Melanocytes reside in the basal and suprabasal layers of the epidermis and oral epithelium. Keratinocytes are the predominant cell type found in the epidermis and oral epithelium. The primary functions of keratinocytes are the formation of a protective barrier and re-epithelialization at sites of injury. Wounds to the skin or oral mucosa will be repaired in part by the migration of keratinocytes.