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Biomedical subjects

A J Louw

Publications and source records attributed to A J Louw.

At least 19 recordsLinked to original sources
PubMed2002

One-year evaluation of atraumatic restorative treatment and minimum intervention techniques on primary teeth.

Atraumatic restorative treatment (ART) and minimal intervention treatment (MIT) techniques were evaluated under field conditions in 5 regions of the Western Cape Province of South Africa, where caries prevalence exceeds 60% and remains mostly untreated. The purpose of the study was to compare and evaluate results of ART and MIT techniques in the primary dentition of 6-9 year-old schoolchildren using glass-ionomer (GI) (Fuji IX) and compomer (Dyract AP) materials. At baseline 401 children were treated, and 1,119 restorations placed by 5 calibrated dentists, 53% with ART (using hand instruments only) and 47% with MIT (minimal use of slow hand-piece) techniques. Evaluations were done with a CPI periodontal probe to measure marginal defects and to detect decay. A pain assessment for the restoration procedures indicated that 80% of subjects experienced no pain, 18% discomfort and slight pain, and 2% required local anaesthetic. After one year 90.5% of subjects and 80% of restorations were followed up (11.1% lost as a result of exfoliation); of these restorations 86% were clinically acceptable (84.1% of the ART and 88% of the MIT). With the art technique 82.7% of GI restorations and 85.6%, of compomer restorations were acceptable. With the MIT technique 86.5% of GI restorations and 89.9% of compomer restorations were acceptable. Success of restorations per region varied significantly: regions 1 and 2-90%, region 3-80%, region 4-70% and region 5-95%. There were no significant statistical differences in respect of materials or methods employed. ART and MIT techniques were well accepted as complementary caries approaches by operators. One-year results show that ART and MIT techniques were successful, substantiating its use for the primary dentition in areas with high caries prevalence. Longer-term assessments are required.

Anesthesia, Dental↗
PubMed2001

Dental fluorosis and caries experience in relation to three different drinking water fluoride levels in South Africa.

OBJECTIVES: The purpose of this study was to determine the relationship between caries experience, degree of fluorosis and different concentrations of fluoride in the drinking water of children. SAMPLE AND METHODS: The study included 282 children aged 10-15 years, who lived continuously since birth in three different naturally fluoridated areas (Leeu Gamka, 3.0; Kuboe 0.48 and Sanddrif 0.19 p.p.m. F), with virtually no dental care or any fluoride therapy The teeth of the children were examined for caries using the DMFT index according to th WHO criteria and for fluorosis, using Dean's criteria according to the WHO guidelines. RESULTS: The prevalence of fluorosis (scores 2, 3, 4 and 5) among the school children was 47% in Sanddrif, 50% in Kuboes and 95% in Leeu Gamka. Almost half the children in the two low fluoride areas had no fluorosis (scores 0 and 1), whereas only 5% in Leeu Gamka had no fluorosis. Of the children in Sanddrif, 42.5% had very mild/mild (scores 2 and 3) fluorosis, 44.3% in Kuboes and 34.1% in Leeu Gamka. Except for one individual in Kuboes, severe fluorosis (score 5) was only observed in the high fluoride area in 30% of the children. According to the Bonferroni adaptation for multiple comparisons, the degree of fluorosis in Leeu Gamka differed significantly from both those of Sanddrif and Kuboes. The mean DMFT for the children in Sanddrif and Kuboe was similar (164 +/- 0.30 and 1.54 +/- 0.24, respectively) but the caries experience of Leeu Gamka (198 +/- 0.22) was significantly higher (P < 0.05) than that of both the other two areas. A strong positive correlation (P < 0.05) was found between the caries experience and the fluorosis scores of children in the high fluoride area (Leeu Gamka) but no correlation could be found in the other two areas. Significantly (P < 0.01) more children had decayed teeth in the high F area (Leeu Gamka) than in the other two areas. CONCLUSION: The results suggest a positive association between high F levels in the drinking water and dental caries. Furthermore, a low caries experience and no difference in DMFT and fluorosis between the two low fluoride areas were found.

Adolescent↗
PubMed2001

Perceptions of fluorosis in northern Cape communities.

The objective of the study was to determine the perception of fluorosis in communities living in the Northern Cape Province of South Africa where there is a considerable range in fluoride levels of drinking water. The fluoride levels of the drinking water were categorised as suboptimal (0.40-0.60 ppmF), optimal (0.99-1.10 ppmF) or supra-optimal (1.70-2.70 ppmF). The teeth of 694 children aged 6, 12 and 15 years were examined. Dental fluorosis occurred among children of all ages in all areas studied. As anticipated there appears to be a direct relationship between fluoride levels in the drinking water and levels of dental fluorosis, and the severity of the condition increased with an increase in levels of fluoride in the water supplies. Children in low fluoride areas showed some form of mild fluorosis (37% very mild and 17% mild). However, 19% of this group experienced moderate or severe forms of fluorosis. In areas with optimal levels of fluoride 30% of children showed a questionable form of fluorosis and 21% mild fluorosis. Moderate or severe forms of fluorosis were recorded in 31% of children in the optimal fluoride area. The Community Fluorosis Index (CFI) scores for the sub-optimal and optimal areas were of medium public health significance and for the supra-optimal area of very high public health significance. Of concern is the high percentage of children (45%) in the supra-optimal area with severe forms of fluorosis. The awareness and concern for stains on teeth were mostly expressed by children with moderate or severe fluorosis. This study suggests that the proposed fluoride concentration (not more than 0.7 ppmF) prescribed in the Regulations on Fluoridating the Water Supplies for South Africa would minimise the risk of dental fluorosis.

Adolescent↗
PubMed2000

Attitudes to water fluoridation in South Africa 1998. Part II. Influence of educational and occupational levels.

The purpose of this report is to investigate the influence of education, income and occupation on public perceptions of water fluoridation (WF). A questionnaire on current knowledge, sources of information, the purpose of WF and its desirability was administered to a representative sample of 2,220 individuals over the age of 18 years. Knowledge of WF increased with educational level (range from 13.5% in the grade 0-5 group to 59% in the grade 12 plus group). Lack of knowledge decreased from 76% to 37% in these groups respectively. Knowledge levels varied from 19% to 68% across the occupational spectrum and from 13% to 88% across the income spectrum. In educational levels up to grade 12, electronic media were most frequently cited as dominant sources of information among 40-50% of respondents, whereas in the grade 12 plus group print media (37%) dominated. Sources of knowledge on fluoridation were largely obtained from print and electronic media for both categories. Only 28% in the educational level up to grade 5 thought the purpose of WF was to protect teeth against decay. This gradually increased to 55% in the grade 12 plus category. More than a quarter of the population in both the occupational and income categories indicated that the purpose of WF was to purify water and protect teeth from decay. The number of respondents who thought that water should be fluoridated increased with level of education from 58% to 70%, while those who disagreed decreased as qualifications increased. The lower- and middle-income groups were more supportive of WF than the very-high-income groups. Persons in high administrative professional and executive positions were more opposed (27%) to WF than semi-skilled and unskilled workers (5%).

Adult↗
PubMed1999

Endemic goitre in the absence of iodine deficiency in schoolchildren of the Northern Cape Province of South Africa.

OBJECTIVE: The study was undertaken to investigate whether endemic goitre still exists in the Northern Cape Province of South Africa more than 55 years after it was reported and, if so, whether iodine deficiency, or fluoride in the drinking water, is linked to the goitres. DESIGN: Cross-sectional study of children in three pairs of towns. SUBJECTS: The 6-, 12- and 15-year-old children (n = 671) who had been lifetime residents in two Northern Cape towns with low levels, two towns with near optimal levels and two towns with high levels of fluoride in the drinking water were recruited through the schools as study participants. RESULTS: Endemic goitre was found in all the towns except one, ranging from 5% to 29%. Iodine deficiency did not prevail in the study area because the median urinary iodine concentration, exceeding 1.58 micromol/l in all but one of the towns, indicated a more than adequate iodine consumption. The drinking water and, to a lesser extent, iodised salt were important sources of iodine. No relationship was found between fluoride in the water and the mild goitre prevalence (5% to 18%) in the four towns with either a low or near optimal fluoride content in the water. The causal factor(s) responsible for the goitres in these four towns were not clear from our data. However, the prevalence of goitre was higher (28% and 29%) in the two towns with high levels of fluoride in the water. CONCLUSION: These results indicate that either a high fluoride level in the water or another associated goitrogen, other than iodine deficiency, may have been responsible for these goitres.

Adolescent↗
PubMed1998

A new microwave acid digestion bomb method for the determination of total fluorine.

A new microwave acid digestion method for total fluorine analysis was compared to the reliable reverse-extraction technique. The commercially available Parr bombs which are compatible with microwave heating were modified for this purpose. The Mann-Whitney statistical test did not show any significant differences (p > 0.05) in the determinations of total fluorine in various samples between the two above-mentioned methods. The microwave method also gave high fluorine recoveries (> 97%) when fluoride was added to different samples. The great advantage of the microwave acid digestion bomb method is that the digestion under pressure is so aggressive that only a few minutes is needed for complete digestion (also of covalently bonded fluorine), which reduces the time for fluorine analysis dramatically, while no loss of fluorine or contamination from extraneous sources could take place during the ashing procedure. The digestion solution was made up of 300 microliter of concentrated nitric acid plus 537 microliter of water. After digestion 675 microliter of approximately 8.5 M sodium hydroxide plus 643 microliter of citrate/TISAB buffer was added resulting in an alkaline solution (pH approximately 12) which was finally adjusted to a pH of approximately 5.3 for fluoride determination.

Acids↗
PubMed1995

Effectiveness of two school-based caries preventive programmes.

Although the efficacy of school-based preventive programmes is well established, their effectiveness under conditions prevailing in the community require further exploration. A longitudinal study was conducted to assess the community effectiveness of two school-based caries preventive programmes. A group of 150 primary school pupils, 10-15 years old were randomly selected from each of three primary schools (Dagbreek, Vergesig, De Villiers) in the Boland town of Robertson. The sample comprised 75 10-12 year-olds and 25 in each of the 13, 14 and 15 year age groups. The 75 (10-12 year-olds) constituted the experimental cohort, which was to be followed up over a period of 3 years and compared to the 13-15 year-olds, the control or baseline cohort. The experimental cohort in Vergesig was exposed to a daily toothbrushing programme with a fluoride dentifrice, the Dagbreek children were exposed to the same regimen plus a weekly 0.2 per cent fluoride rinse and the De Villiers cohort acted as a control group for contamination and co-intervention. The DMFT index (WHO, 1987) was used as a caries measure. Dagbreek showed a reduction of 0.96 DMFT (14.2 per cent) and Vergesig of 1.85 DMFT (24.5 per cent). The difference is attributed to a higher baseline DMFT at Vergesig. The weekly fluoride rinse did not confer any additional benefit. Although the caries reduction was lower than that generally found in clinical trials, the two intervention programmes were cost-effective.

Adolescent↗
PubMed1995

Dental status of rural school children in a sub-optimal fluoride area.

Past investigations by us have shown high levels of caries experience in rural coloured school children of the Western Cape. These studies were all undertaken in fluoride poor areas. In contrast studies of children in areas with optimal and higher concentrations of fluoride in their drinking water have shown lower DMFT scores. On a previous visit to the town of Fraserburg in the North Western Cape we observed fluorosis in children, although the fluoride content of the municipal drinking water was sub-optimal (0.68-0.78 ppm F-). The purpose of this study was therefore to measure the dental status of 6, 12 and 15 year old school children using the dmft, DMFT and Dean's Fluorosis Index according to the 1987 WHO guidelines. The examinations were done by two calibrated examiners using portable equipment. Results showed low mean dmft values of 3.31 +/- 3.90 and 0.22 +/- 0.86 for the 6 and 12 year olds respectively. The corresponding DMFT scores including that for 15 year olds were 0.08 +/- 0.35; 1.45 +/- 1.81 and 1.00 +/- 1.60 respectively and no significant statistical gender differences were observed (p>0.05). The mean fluorosis scores for 6, 12 and 15 year olds were 1.68 +/- 1.05; 2.78 +/- 1.34 and 2.90 +/- 1.58 respectively. For both the 12 and 15 year olds the severity of fluorosis ranged from no fluorosis to severe mottling and corrosion. It can be concluded that the results even at a sub-optimal fluoride level show a high similarity to the dental status of children in rural fluoride rich areas. Defluoridation of the Fraserburg municipal drinking water therefore becomes imperative and a concentration of 0.4 ppm F- is suggested. Furthermore the children have no access to dental services and this has led to accumulated needs which demand urgent addressing.

Adolescent↗
PubMed1994

The relationship between plaque index scores, fluoride content of plaque, plaque pH, dental caries experience and fluoride concentration in drinking water in a group of primary school children.

The aim of this study was to determine the relationship between fluoride in drinking water, plaque and dental caries experience in a sample of primary school children from a fruit farming (mainly grapes) area. The children who qualified for the study (n = 177) were placed into three groups according to the concentration of fluoride in their drinking water namely, less than 0.4 ppm (group A), between 0.4 and 1.6 ppm (group B) and more than 1.6 ppm (group C). Most children (78.5%) did not have a toothbrush. Plaque scores were significantly lower in groups B and C. A statistically significant inverse correlation was observed between plaque scores and fluoride content of plaque (p < 0.05). Plaque pH did not differ significantly between the groups. The concentration of fluoride in plaque was high and increased with increasing concentration of fluoride in the drinking water. Dental caries experience was relatively low in primary (dmft = 2.15; 2.07; 1.79) (p > 0.05) and permanent teeth (DMFT = 1.22; 1.43; 1.38) (p > 0.05). Paradoxically, there was also no significant inverse correlation between dental caries experience and fluoride concentration in drinking water. However, the significant inverse correlation between fluoride content of plaque and caries experience supports the contention that fluoride can be accumulated in plaque and act as a reservoir which provides prolonged elevated levels of fluoride to produce a cariostatic effect. It is postulated that the high fluoride levels in the plaque reservoir is responsible for the relatively low caries experience, the significant differences in caries experience between the groups and the poor correlation between dental caries experience and fluoride concentration in drinking water.

Child↗
PubMed1993

Root caries in a sample of elderly persons.

With the anticipated increase in the aged adult population and the associated gingival recession, the prevalence of root caries is expected to increase. The purpose of this study was to determine the experience and distribution of root caries in a group of aged adults living in Kayelitsha. All non-institutionalized elderly black adults participating in a community geriatric programme were examined. Root caries was recorded using visual and tactile criteria and expressed as the root caries index (RCI) rate. The mean age of the subjects was 65.2 years, the mean number of teeth present was 17.3 and the mean RCI rate was 2.2 per cent. All subjects had gingival recession while only 23.8 per cent had root caries. No surfaces with restored root caries lesions were found. In the maxilla the highest RCI rate was observed on the interproximal surfaces of the posterior teeth (4.4 per cent) but in the mandible the buccal surfaces of the posterior teeth had the highest RCI rate (4.2 per cent). In both the maxilla and the mandible the lingual surfaces of the anterior teeth showed no root caries. Maxillary teeth did not have a significantly higher root caries attack rate than mandibular teeth. Root caries does not appear to be a public health problem in the sampled population.

Age Distribution↗
PubMed1991

A caries preventive programme for Robertson school children--baseline data.

This study describes the baseline caries experience of a cohort school children in the Robertson area who were selected to take part in a longterm school-based preventive programme. On the whole baseline DMFT values for the various age groups did not differ significantly except for the 13-year-olds at Vergesig who had significantly higher values than those obtained at the other two schools. The D-component predominated with a moderate M-component and no filled teeth. The teeth at risk for the respective age groups did not differ significantly between the schools. The frequency of caries experience decreased from the molars to the central incisors except for the canines which were least vulnerable. The DMFT values were high and warrant the search for the most suitable preventive measures to facilitate reduction towards the WHO goal of 3 for 12-year-olds by the year 2000.

Adolescent↗
PubMed1989

CPITN: a tool in the planning of dental services.

The need for a systems approach in the planning of dental public services has been emphasised. A random sample of 1,400 farm labourers and their dependants was assessed using the CPITN index. This data was used to estimate manpower and time requirement based on treatment strategies. Results indicate that virtually everybody aged 7 years and older (94 per cent) require oral hygiene education, 79 per cent need a scaling, while 5 per cent need complex treatment. The need for scaling increased from 61 per cent among 7 to 19-year-olds to 98 per cent in the over-20-year-olds. A small proportion (22 per cent) of sextants amongst 7 to 19-year-olds need scaling, compared with 82 per cent in the over-20 group. While no sextants in the 7 to 19-year-olds require complex treatment, a negligible proportion (0.43 per cent) among over-20-year-olds need such treatment. The findings are extrapolated to the sample population and the times for each procedure used to calculate resources for treating the sample population. It is estimated that approximately 7.3 working years would be required to provide the necessary treatment. In terms of manpower it is estimated that seven full-time oral hygienists and one part-time dentist will be needed to fulfil the total treatment needs. The CPITN appears to be an appropriate tool in the planning of dental health services. Planners should, however, relate estimates to available resources and establish priorities accordingly.

Adolescent↗
PubMed1986

Enamel-fluoride levels in deciduous and permanent teeth of children in high, medium and low fluoride areas.

The surface enamel-fluoride concentration (approximately 4 microns) of both deciduous and permanent teeth of the central upper incisors were determined in 5-7 and 11-13-year-old children, who were born and bred in isolated areas with naturally high (3.7 parts/10(6)), medium (0.6 parts/10(6)) and low (less than 0.1 parts/10(6)) fluoride in the drinking water. Samples were taken in vivo by an acid-etch procedure and fluoride levels measured with an adapted fluoride-ion selective electrode. There were no significant differences in the fluoride concentrations or between etching depths between boys and girls, none between the contralateral incisors nor between the etching depths of deciduous and permanent teeth either in a single area or the three different ones. However, a highly-significant difference (p less than 0.01) was found in the enamel fluoride levels between the deciduous and permanent teeth in a fluoride area or among the three different fluoride areas. The ratio of the mean enamel fluoride concentration of permanent teeth to that of deciduous teeth increased with rise in fluoride in the drinking water. It is concluded that the different lengths of time, during which the crowns of deciduous and permanent incisor mineralize, contribute to this differing ratio.

Adolescent↗
PubMed1986

Surface enamel fluoride concentrations of different types of human teeth in a high- and near-optimal-fluoride area.

The surface enamel (approximately 4 micron) fluoride concentrations of different tooth types (11, 21, 22, 23, 24) were determined in 12-13-year-old children who were life-long residents in a naturally high (3.70 ppm) and in a near optimal (0.62 ppm) fluoride area. Enamel biopsies were taken by means of an acid-etch procedure, and the fluoride levels were measured with an adapted fluoride-ion-selective electrode. The enamel fluoride concentrations were related to the fluoride levels of the drinking water, and it appeared that the enamel fluoride concentrations of the different tooth types (except for the pre-molars) were associated with the length of the pre-eruptive period. In general, for both areas, the mean enamel fluoride concentrations increased from the central incisor to the lateral incisor and were found to be the highest in the canine, while the mean fluoride content of the first pre-molar nearly equaled that of the central incisor. No statistically significant differences (p greater than 0.05) were found between the enamel fluoride concentrations of the different tooth types or the etching depths, from different sexes.

Acid Etching, Dental↗