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.
Maxillofacial and oral surgeons and orthodontists are currently treating an increasing number of black South African patients needing orthognathic surgical procedures. Surgical and orthodontic cephalometric analyses developed for caucasian populations has been shown to be inadequate for other racial groups (Connor and Moshiri, 1985, Briedenhann and Roos, 1988 and Flynn, Ambriogio and Zeichner, 1989). The purpose of this study was to evaluate mean measurements for black South African adults which would be comparable in diagnosis and treatment planning, to the analyses of Burstone et al., (1978) and Legan and Burstone (1980), known as Cephalometrics for Orthognathic Surgery (COGS). Lateral cephalometric radiographs of 15 male and 15 female black South African adults were evaluated for both hard and soft tissue measurements according to parameters of the COGS analyses. The results of this study showed that the cephalometric measurements established for North American caucasians by Burstone et al., (1978) and Legan and Burstone (1980) were at variance to those measurements found in a black South African population group. Thus orthodontic and orthognathic surgical treatment planning for black South Africans may be more relevant if the diagnosis is based on standard measurements specific for this particular racial group.
A portable glucometer method was used to measure clearance of salivary glucose in 31 black and in 28 white 12-year-old school children. The aims of this study were to evaluate a readily available portable glucometer method and to investigate salivary glucose clearance as a marker of caries risk. Following the initial evaluation, we adapted the portable adapted glucometer method and found it reproducible and suitable for the measurement of salivary glucose clearance. Black children had almost double the salivary clearance rates of white children. No significant differences in salivary glucose clearance were seen between caries free (DMFT = 0) and caries active (DMFT > or = 3) children. Salivary glucose clearance is not suitable as a single caries risk predictor.
An in vitro study was performed to ascertain the marginal seal elemental composition of amalgam restored extracted teeth of known marginal leakage. Occlusal cavities were cut in 400 caries free extracted teeth and left unlined or lined with one of 5 bases. A varnish was applied to half the cavities followed by restoration with a low copper or high copper amalgam to produce 20 restoration combinations. The teeth were stored in 1 per cent NaCl and thymol for 3 and 12 months at 20 degrees C whereafter a standard fluorescent dye marginal leakage test was performed on 320 specimens (eight teeth per treatment). Restoration combinations were grouped into 4 seal classes depending on percentage marginal seal achieved for each combination: 0-25 per cent; 26-50 per cent; 51-75 per cent and 76-100 per cent. The 80 remaining teeth (2 teeth per treatment) were fractured to expose the restoration and cavity surface, covered with marginal seal material and this was analysed by energy dispersive X-ray analysis. Elemental seal composition was compared to percentage marginal seal achieved using ANOVA and Tukey's test with significance set at p < 0.05. Numbers of elemental analysis specimens falling into each marginal seal class was 0-25 per cent = 48; 26-50 per cent = 18; 51-75 per cent = 10; 76-100 per cent = 4. Of the 16 elements detected, nine were significantly linked to sealing/leakage: Ca, Cl, Cu, Mg, Hg, P, Ag, Sn and Zn. The findings have a bearing on the improved longevity of amalgam restorations.
During the past five years, the media were inundated with reports of professional people leaving the country. A number of the emigrants were dentists who went to the United Kingdom to practise their profession. The purpose of this study was to gather data on South African qualified dentists registered with the General Dental Council (GDC) in the United Kingdom and to provide baseline information on this group of health professionals. The results of the study showed a steady increase in the number of South African qualified dentists registered with the GDC in the period 1990 to 1995. Attrition of South African qualified dentists is, however, not entirely due to emigration to the United Kingdom.
The objective of this paper was to examine the cost of oral health in South Africa over the past decade Particular emphasis was placed on the contribution made by medical schemes which is the main source of private health care funding. Some of the problems facing this huge industry were also briefly explored. Primary aggregate data on oral health expenditure were obtained from the Department of Health, Pretoria and from the offices of the Registrar of Medical Schemes, Pretoria. The results show that in 1994, 4.7 per cent of the total health care budget was allocated to oral health. Of this amount, 14.2 per cent came from the state, 71.9 per cent from medical schemes and the remainder calculated to be from direct out-of-pocket payments. Furthermore, real expenditure for oral health by medical schemes grew robustly and almost continuously from 1984 through to 1994, generally outstripping medical inflation.
The WHO classification of odontogenic cysts includes the radicular (residual) and paradental (inflammatory collateral; mandibular infected buccal) cysts as inflammatory odontogenic cysts. Because the paradental group of inflammatory cysts may clinically cause diagnostic and therapeutic problems when they are associated with first and second molar teeth it was decided to review the literature and present an additional case. The aetiology and histological features of the inflammatory collateral cyst, the paradental cyst and the mandibular infected buccal cyst are identical and the differences that exist in their clinical and radiological presentation can be related to the different teeth that are involved and the difference in the ages at which these teeth erupt. These cysts represent the same entity and their treatment is dependent on the tooth involved. With the aid of magnetic resonance imaging (MRI) the distinction between a paradental cyst on the buccal aspect of a molar tooth and a periodontitis can be made.
Studies in England, USA and Australia, have shown that the working hours of female dentists do not differ significantly from the working hours of their male counterparts, until they have children. The purpose of this study was to establish whether the same phenomenon exists in South Africa and to compare working patterns of South African male and female dentists regarding nature of practice/employment, location of practice, work satisfaction and breadwinner status. Questionnaires were sent to 285 female dentists, selected by their first name in the SAMDC register. An equal number of questionnaires were sent to male dentists, selected according to the proportional random sampling technique. The total response achieved was 35.8 per cent. The female dentists' working hours showed a distinct drop as soon as they started a family (from 86 per cent, practising more than 35 hours per week, to 34 per cent) while the male dentists' hours remained unchanged (90 per cent). The fact that so many more male dentists (81 per cent) than female dentists (19.6 per cent) are primary breadwinners, explains why such a high percentage of female dentists can afford to work part-time. The majority of both male (89.7 per cent) and female (70 per cent) dentists are in private practice. However, a considerably larger percentage of females work for a salary in State clinics and at Universities. This study shows that gender, breadwinner status and the presence and age of children have a marked influence on the working patterns of South African dentists.
Various techniques have been described to extrude the roots of fractured teeth to facilitate prosthetic restoration. Many of these have the disadvantage of poor aesthetics, they require skill in fabrication and fitting, and there is often inadequate control over the amount of extrusion. With the technique described, root canal therapy is completed initially and a cast gold post is cemented into the root canal. The post has a channel extending from the labial to the palatal aspect. A temporary acrylic crown is fitted to restore aesthetics, and the channel is extended though the palatal and labial surfaces. An orthodontic wire framework with a horizontal strut at the level of the original incisal edge of the fractured tooth is then bonded to the adjacent abutment teeth. The amount of extrusion required is estimated and a corresponding reduction is made in the length of the acrylic temporary crown. An elastic threaded through the channel and looped over the horizontal strut of the framework provides the extrusive force. A 6 week retention period is required following the extrusion. Periodontal surgery is then carried out if necessary, and a new provisional crown is placed. The final porcelain restoration is fitted after 6 months.
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).
