Research Outputs (Oral Health Sciences)
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Item Base solubility and marginal sealing in amalgam restored teeth(1991) Grossman, E. S.; Witcomb, M. J.; Matejka, J. M.Item Social class, parents' education and dental caries in 3- to 5-year-old children(1990) Chosack, A.; Cleaton-Jones, P.; Matejka, J.; et alThe caries prevalence of 1273-, 4- and 5-y-old white children was determined with mirror and probe under natural light at mother and child clinics. The social class of the family, the educational level of the mother and that of the father were determined from a questionnaire filled in by the accompanying adult at the time of examination. Both social class and parent's education had a statistically significant influence on the caries prevalence: those in the lower social classes and with parents without tertiary education had a much higher prevalence of cariesItem Dental caries in 11-year-old Indians in four religious groups(1990) Dockrat, M.; Cleaton-Jones, P.Item Permanent denition caries in KwaZulu and Namibia 11-year-olds(1990) Hargreaves, J. A.; Cleaton-Jones, P.; Matejka, J.; et alThe permanent dentitions of 11-year-old children in Namibia (n = 295) and KwaZulu (n = 308) living in rural and urban areas were examined using WHO caries diagnostic criteria. In low fluoride areas (less than 0.15 ppmF) significantly more caries was present in rural compared to urban KwaZulu but the prevalences in rural and urban Namibia were similar although significantly higher than in an area with 1.56ppmF in the drinking water. There was significantly more caries in rural Namibia than KwaZulu but the urban prevalences in both regions were similar. It is suggested that the urban findings are useful predictors for the needs of 11-year-old black children but local baseline surveys should be undertaken before considering dental programmes, treatment or preventive, for different rural communities in South Africa.Item Comparison of three fluorosis indices in a Namibian community with twice optimum fluoride in the drinking water(1990) Cleaton-Jones, P.; Hargreaves, J. A.In Otjiwarongo, a town in Namibia with twice the optimum fluoride in the drinking water (1.56 ppm) the Dean (Dean, Arnold and Elvove, 1942), Thylstrup and Fejerskov (Thylstrup and Fejerskov, 1978) and TSIF (Horowitz et al, 1984) indices of fluorosis were compared in permanent teeth of the children aged 11 y living in the region. Fluorosis severety was skewed in all instances to lower scores within each index. With the Thylstrup and Fejerskov and TSIF indices it was possible to compare fluorosis by individual teeth; the former was significantly more sensitive in diagnosis (56 per cent vs 50 per cent prevalence). It is recommended that the aims of a fluorosis investigation be carefully detailed before selecting the fluorosis index to be used. If detailed information on individual teeth related to fluoride ingestion is needed the Thylstrup and Fejerskov index is recommended, especially in areas with raised fluoride intakes where it is anticipated that the fluorosis levels will be mainly in the low levels of severityItem Gingival temperatures in the baboon and Vervet Monkey(1990) Volchansky, A.; Cleaton-Jones, P.; Smith, M.Item Dental caries treatment in Third World populations: a review(1991) Walker, A. R. P.; Dison, E.; Cleaton-Jones, P. E.Item Use of DI-S and CPITN as predictors in dental caries studies in the primary dentition(1991) Cleaton-Jones, P.; Hargreaves, J. A.; Beere, D.; et al.The DI-S (simplified oral debris index), CPITN (Community Periodontal Index of Treatment Needs) and dmfs (dental caries experience in the primary dentition were recorded in 395 5-year-old black children living in rural and urban areas of Southern Africa. The DI-S and CPITN were grouped, independently and together, to examine their use as simple field methods of predicting dental caries. For each grouping the sensitivity, specificity and positive and negative predictor values were calculated. A CPITN grouping of 0 or of two or more sextants with bleeding, provided the most convenient specificity, sensitivity and predictor values. It is recommended that this simple method should now be used in prospective studies of caries activity.Item The morphogenesis of bone in replicas of porous hydroxyapatite obtained from conversion of calcium carbonate exoskeletons of coral(1991-06) Ripamonti, UgoThe morphogenesis of bone in a porous hydroxyapatite substratum was studied after intramuscular implantation in adult primates. Replicas of porous hydroxyapatite that had been obtained after hydrothermal conversion of the calcium carbonate exoskeleton of coral (genus Goniopora) were implanted intramuscularly in twenty-four adult male baboons (Papio ursinus). Serial sections from specimens that had been harvested at three, six, and nine months showed that initially the formation of fibrous connective tissue was characterized by a prominent vascular component and by condensations of collagen fibers assembled at the interface of the hydroxyapatite. The morphogenesis of bone was intimately associated with the differentiation of the connective-tissue condensations. Bone formed without an intervening endochondral phase. Although the amount of bone varied considerably, in several specimens extensive bone developed, filling large portions of the porous spaces and culminating in total penetration by bone within the implants. The mean volume fraction composition of the specimens was 20.8 +/- 1.0 per cent (mean and standard error) for bone, 17.3 +/- 1.7 per cent for connective-tissue condensation, 31.9 +/- 1.0 per cent for fibrovascular tissue, 6.4 +/- 0.6 per cent for bone marrow, and 34.6 +/- 0.5 per cent for the hydroxyapatite framework. The amount of bone and marrow increased at each time-period, and the hydroxyapatite framework was significantly reduced between six and nine months. This indicated a moderate biodegradation over time, which was possibly a result of incomplete conversion of carbonate to hydroxyapatite. Linear regression analysis showed a negative correlation between the hydroxyapatite framework and the magnitude of bone formation within the porosities of the hydroxyapatite (p = 0.0001). Biochemical coating of the hydroxyapatite substratum with an allogeneic fibrin-fibronectin protein concentrate prepared from baboon plasma did not significantly increase the amount of bone formation within the porous spaces. The hydroxyapatite substratum may have functioned as a solid-phase domain for anchorage of bone morphogenetic proteins.