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Biomedical subjects

P Cleaton-Jones

Publications and source records attributed to P Cleaton-Jones.

At least 37 records · Page 2Linked to original sources
PubMed1996

Epidemiological profile of graduates of the Wits Dental Faculty 1927-1995.

The Wits dental school was first proposed in 1921 but had no premises until a private dental clinic was taken over in 1924 by the University, the same year that the Bachelor of Dental Surgery regulations were agreed to. In 1925 the first dental students registered and a year later, in 1926, the first seven lecturers in dental surgery were appointed. Since the first two graduates in 1927, 1916 dentists have graduated from the school as have 63 oral hygienists. Of the dentists 116 are female and 127 are black, Chinese, coloured or Indian. Regarding postgraduate qualifications, 346 have been awarded by the University on behalf of the dental school. This paper describes patterns in numbers of graduates, proportions registered in South Africa and contrasts registered South African dental school graduates with registered graduates from outside the country. It is clear that the Wits dental school has made a major contribution to South African society.

Dentists↗
PubMed1995

Diseases and lesions associated with third molars. Review of 1001 cases.

This study reports on a retrospective survey of 1001 panoramic radiographs in a dental school population of persons with impacted third molars. The objective was to determine the association between pathologic conditions visible on radiographs and third molar teeth. In the series 2872 impacted third molars were examined. The most common problem seen radiolucencies. Other than caries, occurrence rates were low. Statistically significant differences in occurrences rates were seen within and between jaws for various pathologic conditions. The low rates did not offer support for the likely presence of pathologic conditions to be an indication for third molar removal.

Adolescent↗
PubMed1994

Variations in oral temperature.

This study investigated the temperature of healthy oral mucosa and underlying bone. Using a fine thermocouple and digital thermometer, four groups of temperatures were measured: (i) adjacent to unerupted third molars before and after surgical removal (n = 51); (ii) at the same site in patients not undergoing surgery (n = 30); and (iii) at the buccal incisor mucosa (n = 30). In each group sublingual temperatures were measured in order to calculate the temperature differential between measurement site and sublingual temperature to compensate for variations between sites and individuals. In the final group (iv) (n = 10) sublingual temperature was recorded in a closed mouth. Mean alveolar bone temperature was 5 degrees C cooler than overlying mucosa, and mean post-operative mucosal temperature was some 2.5 degrees C cooler than before operation (t = 2.32, P < 0.001). Sublingual temperature, in a closed mouth, remained relatively constant. In an open mouth, in both anterior and posterior regions, there were statistically significant decreases in sublingual temperature and in mucosal temperature differentials. Significant differences were also found between temperature differentials calculated using sublingual temperature measured at baseline and after 10 min. This indicates that sublingual temperature should be measured just prior to measuring a mucosal site.

Adolescent↗
PubMed1994

Dental caries and social factors in 12-year-old South African children.

Dental caries prevalence (percentage caries-free) and experience (DMFS) were recorded, in 414 12-yr-old Indian and 401 white children living in adjacent urban communities with the same fluoride concentration in the drinking water (0.21-0.33 ppm) using WHO (11) criteria. Details of social factors: education level, family income, home space and occupants and parental occupation were obtained by questionnaire. Dental caries was significantly worse in the Indian children with regard to numbers caries-free (30%--white and 40%--Indian) and DMFS mean (sd) (3.65 (3.98) and 2.66 (3.49) working group, respectively). Social class, white or blue collar, family income and room to person ratio were significantly associated with dental caries in the white children but there were no significant associations in the Indian children. Multiple regression analysis showed race and sex to be significant factors.

Chi-Square Distribution↗
PubMed1994

Salivary lactobacilli explain dental caries better than salivary mutants streptococci in 4-5-year-old children.

The present comparative study was undertaken to determine which of the bacteria, lactobacilli (lbc) and mutans streptococci (ms), in saliva better explains the variation of caries in 2728 South African 4-5-yr-old children. Caries was diagnosed according to WHO criteria. For lbc, the Dentocult system was used. The number of ms in stimulated saliva was counted on MSB agar plates. For correction of confounding factors, data on the frequency of intake of sweets were derived from extensive interviews. Oral hygiene was determined according to the simplified debris index of Greene & Vermillion. Simple correlation analyses between dmfs and bacterial counts were done for the total material and for three caries intervals by calculating Spearman's and Pearson's coefficients of correlation. Multivariate regression analyses were done on all intervals to correct for the confounding effects of regular intake of sweets, presence of salivary ms or lbc, and oral hygiene. Of the children, 68% had detectable lbc in the saliva, and 74% had ms. Except for children with more than 6 dmfs, the explanatory values, i.e., percentage of variation in dmfs explained, were higher for the lbc than for ms. Before correction, the values for the total material were 15 vs 6%; for children with caries, 7 vs 5%; for those with 1-6 dmfs, 5 vs 0.4%; and for those with more than 6 dmfs, 0.3 vs 2%. All r-values were reduced after correction, indicating that the confounders explain some of the correlation between dmfs and bacterial count.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1994

Associations of dental caries with salivary mutans streptococci and acid producing bacteria in 5-year-old children from KwaZulu and Namibia.

Two hundred and eighty-five, 5-year-old children from rural and urban KwaZulu and Namibia were examined for dental caries, salivary mutans streptococci and salivary acid producing bacteria. The findings showed statistically significant correlations between salivary mutans streptococci counts and ds and dmfs scores in all groups of children, the highest values being in Namibian children. Salivary acid forming bacteria had low correlations with few statistically significant groups. While salivary mutans streptococci counts may be a useful caries screening method in children of this age, salivary acid forming bacterial counts appear unsuitable.

Acids↗
PubMed1993

Prevalence of dental caries in 4- to 5-year-old children partly explained by presence of salivary mutans streptococci.

The correlation between dental caries and the number of oral mutans group streptococci (ms) present has been shown to be weak. The aim of this investigation was to study associations between caries experience (decayed, missing, and filled surfaces [dmfs]) and the number of ms in stimulated saliva, with emphasis on the level of disease and the confounding effect of regular intake of sweets, the presence of salivary lactobacilli, and oral hygiene. In some 2,700 4- to 5-year-old South African children of different ethnic origins, caries was diagnosed on the basis of World Health Organization criteria and saliva samples were analyzed for ms after cultivation on mitis salivarius-bacitracin agar and for lactobacilli by using the Dentocult kit. Oral hygiene was scored on the basis of the Greene and Vermillion simplified debris index, while data on intake of sweets were derived from extensive interviews. Pearson's coefficient of correlation was computed, and multiple regression analysis was performed to correct for confounding factors. The distribution of the children in the eight caries classes was strongly associated with the ms class (P < 0.001), with those in the lower ms classes generally having low dmfs scores and those in the higher ms classes having dmfs scores distributed over the whole range. The r value for the two variables was 0.25 for the total material; this was reduced to 0.18 by correction for confounding factors. The corresponding values for children with caries were 0.21 and 0.17, for those in the 1 to 6 dmfs interval they were 0.07 and 0.03, and for those in the 7 to 81 dmfs interval they were 0.16 and 0.14. The data imply that the explanatory values for ms, those for the lower caries interval not counted, ranged from 6 to 2%. The unexpected results for children with caries might be due to their distribution pattern. It is concluded that there is a need for reevaluation of ms as a risk factor in dental caries.

Candy↗
PubMed1992

Biocompatibility testing of a silicone maxillofacial prosthetic elastomer: soft tissue study in primates.

Little information exists on the biocompatibility of maxillofacial prosthetic materials. Cosmesil material is a purpose-designed facial prosthetic elastomer that has an established clinical profile in humans but results of biocompatibility testing have not been published. Cosmesil, acrylic resin (positive control), black surgical gutta-percha (negative control), and Silastic 382 material (Dow Corning, Midland, Mich.) (reference control) were processed as custom-designed implants. The implants were inserted into five chacma baboons for a 12-week period in intraosseous, subperiosteal, submucosal, and intramuscular sites. The histologic assessment was based on a modified form of the FDI-ISO Technical Report 7405 for subcutaneous implants. An evaluation was made of capsule formation and inflammatory response. The statistical analysis involved a three-way ANOVA and a Tukey-Kramer Student range test. The critical level of statistical significance chosen was p less than 0.05. The study found that gutta-percha provoked a statistically significantly thicker capsule and a severe inflammatory response. Acrylic resin, Cosmesil material, and Silastic 382 material produced capsule formations and an inflammatory response that did not differ significantly. Cosmesil material is not manufactured as an implant material, but from the present findings it is considered acceptably biocompatible for its intended use where there may be contact with internal tissue spaces that are contiguous to external surfaces.

Acrylic Resins↗
PubMed1991

Correlations between caries prevalence and potential etiologic factors in large samples of 4-5-yr-old children.

A data base containing information on dental caries, oral hygiene, gingival state, Streptococcus mutans and lactobacillus counts, and salivary flow rate and buffer capacity in some 2800 4-5-yr-old South African children was created in 1984. The children were equally distributed in four groups; rural black, urban black, urban Indian, and urban white. In this study, the data were used for simple linear correlations between all the factors including caries as well as stepwise multiple regression analyses between caries prevalence and the independent factors in each of the four groups. The highest r value obtained in the single correlations was 0.56 for dmfs/lactobacillus count in the white group. The overall pattern of the groups did not vary much. In the stepwise multiple regression analyses, lactobacilli entered first in all groups. S. mutans and oral hygiene interchanged as Nos. 2 and 3, and gingival state or buffer capacity came out as No. 4. The highest percentage of caries variability explained by these regressions was 25%, in the urban black group, while the lowest was 12%, in the indian group. It was concluded that our generally accepted etiologic factors are unsatisfactory to explain variation in caries in observational studies, which among other things might be ascribed to the inadequate way these factors generally are measured or estimated.

Black or African American↗
PubMed1991

Use of DI-S and CPITN as predictors in dental caries studies in the primary dentition.

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.

Black or African American↗
PubMed1990

Pulp response to a composite resin inserted in deep cavities with and without a surface seal.

The objective of the present investigation was to observe pulp response to a composite material (Occlusin) placed in deep cavities with and without a zinc oxide-eugenol covering. Deep cavities were prepared in 116 teeth of four young baboons and divided into four groups. In group 1, Occlusin material was placed directly into the cavity, without etching, to approximately half the depth, cured, and covered to the surface with zinc oxide-eugenol. In group 2, the cavities were etched, a bonding agent was applied, and Occlusin material was used and cured in two increments to fill the cavities up to the surface. In group 3, the composite resin was placed in two increments as in group 2, but without etching and bonding; and in group 4 (control), the cavities were filled up to the surface with zinc oxide-eugenol. Follow-up times were 5, 30, and 90 days. Light microscopy revealed that, although some differences were observed, a good pulp response was evident in all groups.

Acid Etching, Dental↗
PubMed1990

Pulp revascularization in reimplanted immature monkey incisors--predictability and the effect of antibiotic systemic prophylaxis.

In 32 monkeys 105 immature maxillary incisors were extracted and reimplanted either immediately or after 30 or 60 min wet or dry storage. Of the monkeys, 17 (group I) did not receive and 15 (group II) received prophylactic treatment with 4 mg/kg doxycycline before extraction and 2 mg/kg for 5 d after reimplantation. The observation time varied from 6 to 8 weeks. After being histologically processed, the material was evaluated with respect to the amount of vital tissue and presence of micro-organisms in the pulpal lumen. A comparison revealed no difference in the results between the groups. The results were therefore pooled and statistically analysed with respect to the significance of apical foramen width, extra-alveolar time, wet or dry storage and presence of micro-organisms in the pulpal lumen for the occurrence of complete pulp revascularization (CPR). The overall frequency of CPR was 18%. Log-linear analyses (SAS, 1985) of the material as a whole or of separate parameters consistently revealed a relationship between presence of micro-organisms and absence of CPR (P = 0.0001). A higher frequency of CPR and a lower frequency of micro-organisms (P = 0.05) was found only for the group of immediately reimplanted teeth. The presence of micro-organisms could be explained for 61 teeth. In 27 of these, blood clots containing bacteria in the apical portion of pulpal lumen indicated contamination during the extra-alveolar time, while in 34, the micro-organisms originated from plaque covered mechanical damage in the cervical part of the root surface.

Animals↗
PubMed1990

Effect of topical application of doxycycline on pulp revascularization and periodontal healing in reimplanted monkey incisors.

Maxillary incisors in 47 monkeys, 54 in the experimental group (I) and 117 in the control group (II), were extracted and reimplanted, either immediately or after 30 or 60 min wet or dry storage. Incisors in the experimental group I were additionally kept 5 min in a suspension of 1 mg doxycycline in 20 ml physiologic saline, freshly prepared for each of the 15 animals before reimplantation. The observation time varied from 6 to 8 weeks. The teeth were removed in tissue blocks, histologically processed and evaluated for occurrence of complete pulp revascularization (CPR), presence of the micro-organisms in the pulpal lumen and ankylosis or inflammatory root resorption. Then the results were statistically evaluated, using log-linear analyses and chi-square tests (SAS, 1985) for the comparisons between group I and group II. These analyses revealed that topical application of doxycycline increased the frequency of complete pulp revascularization (P less than 0.002) and decreased the frequency of micro-organisms in the pulpal lumen (P less than 0.001). Furthermore, the frequencies of ankylosis (P less than 0.05) and inflammatory root resorption (P less than 0.001) were also decreased compared with the control group of teeth. It was concluded that the effect of topical treatment with doxycycline was most probably exerted on the micro-organisms that contaminated root surface during the extra-alveolar time; contamination of necrotic pulp tissue from the mechanical damage in the cervical part of the root surface was not affected.

Animals↗
PubMed1990

Comparison of three fluorosis indices in a Namibian community with twice optimum fluoride in the drinking water.

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 severity.

Chi-Square Distribution↗
PubMed1990

Community Periodontal Index of Treatment Needs (CPITN) in KwaZulu and Namibia in 11-year-old children in 1988.

A sample of 603 11-year-old children from four low fluoride (less than 0.15 ppm) and one higher fluoride (1.56 ppm) communities in Namibia and KwaZulu were examined in 1988 using the CPITN. In a rural low fluoride community in Namibia only 6 per cent of children had healthy mouths compared with 42-58 per cent in the other communities. The main periodontal lesion seen was gingival bleeding (19-47 per cent) followed by calculus (6-47 per cent). There is a need for both oral hygiene improvement and simple intervention.

Child↗