The Journal of the Dental Association of South Africa = Die Tydskrif van die Tandheelkundige Vereniging van Suid-Afrika最新文献

Lactobacilli that are most frequently associated with active caries lesions in dentine were isolated and identified as part of a research project which aims to determine the role of the predominant species of these organisms in the carious process. Samples of carious dentine were collected from 12 patients with open caries lesions (Group A) and stimulated saliva samples were collected from 12 patients with a DMFT = 0 and confirmed presence of lactobacilli in the oral cavity (Group B). After serial dilutions samples were plated on Rogosa agar and incubated anaerobically at 37 degrees C for 48 hours. Representative colonies were isolated from each sample, using Harrison's disc and species were identified by classical taxonomy. A total of 153 isolates were identified. The redefinition and description of lactobacilli species in recent systematic literature resulted in a new and different species composition of oral lactobacilli as shown in this study, namely: homofermentative species (Group A = 82 per cent; Group B = 90 per cent) were predominantly Lactobacillus paracasei (Group A = 39 per cent; Group B = 30 percent) and Lactobacillus rhamnosus (Group A = 31 per cent; Group B = 41 per cent). Heterofermentative species (Group A = 18 per cent; Group B = 10 per cent) were predominantly Lactobacillus fermentum (Group A = 68 per cent; Group B = 100 percent).

The optimal way to address endodontic failures is to retreat the root canal system first and only then to consider apical surgery. Unfortunately, in practice, it is often not done in this way. Patients are subjected to apical surgery, without any attempts at retreatment. A series of cases is presented illustrating failures of apicoectomy and successful endodontic retreatment.

A rapid epidemiological assessment (REA) of industrial dental erosion was undertaken with the aim of formulating a range of treatment strategies which could be used to settle an industrial dispute. This dispute concerned compensation for a group of adult male metalworkers who had complained of dental sensitivity and that their teeth had been "eaten by acid" at their workplace, an electroplating factory in Springs near Johannesburg, South Africa. The REA methods employed included a clinical examination, a structured socio-demographic questionnaire and colour photographs of each subject. Sixty per cent of the subjects reported pain and/or sensitivity to eating and/or drinking, 76 per cent showed varying degrees of loss of tooth structure, and 25 per cent reported teeth had been lost as a result of the industrial erosion. The project involved negotiating with mine management and trade union representatives, each with conflicting interests, and with people's oral health and large sums of money at stake. In this context, the aim of the research was to design an instrument to resolve conflict and to promote oral health at an industrial site, while retaining scientific objectivity and rigour. As a result of the REA, the workers who were examined are in the process of being compensated, while the National Union of Mineworkers and mine management are engaged in reaching a settlement. Preventive measures have been initiated at the factory. The area has been declared a "respiratory zone", which makes the wearing of respiratory masks obligatory.

The present study investigated student motives for choosing dentistry in five South African dental schools. An attitude questionnaire was complied and administered to all entering students at these schools. The study population comprised 161 students, 92 males and 69 females. Results indicate that in spite of the changing student populations at all universities, the motives for studying dentistry remain essentially the same. Similarities in attitudes to dentistry tend to outweigh differences. Similarities are shown with respect to service, the need for status, independence and financial security. Differences are reflected in the contradictions between service and status, service and regular working hours, service and financial security. The question these findings raise, is how and to what extent students selected for training, based on their current motivation and attitudes will best adapt to changes in the practice of dentistry, health policies, and increased population demands.

The purpose of this in vitro investigation was to determine the shear bond strength of admixed (Dispersalloy), irregular (Oralloy) and spherical (Lojic) amalgams, as well as an admixed gallium alloy (Galloy) to superficial, buccal, human dentine surfaces, using the Scotchbond Multi-Purpose Plus system. The bonds were stressed to failure in an Instron testing machine after 48 hours, and the following values (MPa) were obtained: Admixed = 7.74 +/- 0.7; Irregular = 9.47 +/- 1.4; Spherical = 9.82 +/- 2.4; Galloy = 11.03 +/- 2.5. Data were statistically analysed and fracture sites examined in a scanning electron microscope. Galloy demonstrated a statistical significant higher shear bond strength than to the other types of amalgams (p < 0.01).

In order to assess the response of dentists to the increasing incidence of HIV, a study was conducted to explore their attitudes, knowledge and the additional costs involved in treating HIV positive patients. The response of dentists to the increasing incidence of HIV positive patients is influenced by their fears and concerns about HIV, their knowledge about the disease, and their attitudes towards providing care for HIV patients. The results of this research suggest that the negative response to HIV patients from dentists can be attributed to several factors. Dentists are afraid of contracting the virus, they do not trust the honesty of HIV patients, and they believe there are additional costs involved in treating these patients. In order to provide quality dental treatment for HIV patients, dentists must overcome their misperceptions and feelings of anxiety and fear about HIV. Education is a major weapon in the fight against HIV. Dentists agree there is a need for continuing education despite the fact that their overall knowledge about HIV is good.