K.G. König

The Prevalence of Dental Caries in Europe 1990-1995

Caries prevalence data from recent studies in all European countries showed a general trend towards a further decline for children and adolescents. However, in several countries with already low carie

Prevalence, distribution and background variables of smooth-bordered tooth wear in teenagers in the hague, the Netherlands.

The purposes of the study were: (1) to assess the prevalence and distribution of smooth-bordered tooth wear in teenagers, and (2) to investigate the relationship between smooth-bordered tooth wear and social background, dietary pattern, drinking habits, oral hygiene practices and caries prevalence. In The Hague, The Netherlands, a sample of 345 10- to 13-year-olds and 400 15- and 16-year-olds was clinically examined. The criteria for the assessment of smooth-bordered tooth wear (‘smooth wear’) were in line with the diagnostic criteria for erosion developed by Lussi (1996). In the age group 10–13 years, the percentage of subjects with visible smooth wear (SW1 threshold) was 3% and in 1 subject (0.3%), deep smooth enamel wear was found. Due to the low prevalence, the results for this age group were not analysed further. In the age group 15–16 years, the proportion of subjects with visible smooth wear (SW1 threshold) was 30% and that with at least deep smooth enamel wear (SW2 threshold) 11%. Smooth wear into dentine was found in 1 subject. First molars and upper anterior teeth were affected predominantly. A significant effect on visible smooth wear (SW1 threshold) was found for gender and social background. At mouth level, no significant influence was found for dietary patterns, drinking habits or oral hygiene practices. The caries prevalence was similar in subjects with and without smooth wear.

Time Trends in Caries Experience of 6- and 12-Year-Old Children of Different Socioeconomic Status in The Hague

The caries experience among 6- and 12-year-old children in the The Netherlands from the mid seventies showed a continued decreasing trend. A halt in the decline of caries experience of the primary dentition of 6-year-olds occurred after 1983, whereas among 12-year-old children the decrease in mean DMFS values continued in the period 1980–1989. The 1996 survey in The Hague showed that the decline in caries in 12-year-old native children of low socioeconomic status (SES) has come to an end (average DMFT of 1.1). However, in medium- and high-SES groups, the percentages of caries-free children have continued to rise. Of the medium-SES 6- and 12-year-old children, 79 and 89% were caries-free, respectively; in the high-SES children the respective figures were 84 and 86%. A DMFT of 0.3 in 12-year-olds of medium and high SES was found, the general value was 0.7 and 74% with zero caries experience.

Radiographic versus Clinical Diagnosis of Approximal Carious Lesions

For school-age children, in whom caries activity has declined considerably, the efficiency of bitewing radiographs in diagnosing approximal lesions requires reevaluation. Therefore parallel clinical and radiographic examination of approximal surfaces were carried out in 317 14-year-old children. To assess the degree of agreement between both methods sensitivity and negative predictive value were determined. At the same time previously published data of children aged 8 through 12 years were reassessed. From the results it is concluded that omission of radiographic examination will not result in a substantial loss of information under the age of 12, but above this age it is advisable to include radiographic diagnosis for approximal surfaces.

Effect of 6-monthly applications of chlorhexidine varnish on incidence of occlusal caries in permanent molars : a 3-year study

OBJECTIVES The aim of this study was to assess the effect of a chlorhexidine varnish on occlusal caries incidence when applied 6-monthly into the fissures of erupting and freshly erupted permanent molars. METHODS In a double-blind clinical trial, 332 children aged 5/6 and 11/12 years attending a Child Dental Health Centre were randomly assigned to a control and an experimental group. Criteria for inclusion in the study were that all first permanent molars in 5-6-year-olds and all second permanent molars in 11-12-year-olds either had recently erupted, or were in a stage of eruption, or would erupt within half a year. At baseline, counts of dmfs/DMFS and mutans streptococci in saliva were recorded. During a maximum of 3 years, every 6 months the occlusal surfaces of molars in the experimental group received a 40% chlorhexidine varnish application, whereas those in the control group received a placebo varnish application. RESULTS Data of 316 children were analysed and ANOVA showed no significant occlusal caries reduction in this sample of Dutch 5/6- and 11/12-year-old children. After stratification into low and high caries risk groups, a statistically significant caries-reducing effect on occlusal caries in permanent molars was found in the group of children with > or = 10(6) mutans streptococci per ml saliva (P < 0.05). CONCLUSION Six-monthly application of chlorhexidine varnish has no caries-reducing effect on occlusal caries in recently erupted permanent molars in a population with low caries prevalence.

Performance of electrical resistance measurements adjunct to visual inspection in the early diagnosis of occlusal caries

The detection of small carious lesions at occlusal surfaces is a difficult task, particularly in low caries prevalence populations and individuals. The aim of this study was to evaluate the performance of electrical resistance measurements (ERM) in diagnosing small dentinal lesions at one site per occlusal surface in low caries prevalence populations when used adjunct to visual inspection, and to compare the performance of ERM to that of radiographic examination. The occlusal surfaces of 81 third permanent molar teeth extracted from young adolescents were diagnosed by four examiners, who measured the electrical resistance of enamel on a one measurement per surface basis, and furthermore assessed the occlusal surfaces visually and radiographically. The teeth were sectioned for validation by histological examination. The ERM had the highest sensitivity (0.67), and visual inspection had the highest specificity (0.89). ROC analysis showed no statistically significant differences between the performance of the observers when using visual inspection and ERM (z-score test; P > 0.05). One examiner performed statistically significantly better by measuring the electrical resistance of enamel than by radiographic examination (P < 0.05). The average sensitivity and specificity of the three diagnostic systems were used to express the positive and negative predictive values as a function of caries prevalence. At a caries prevalence of 0.2 the negative predictive values for visual inspection, ERM and radiographic examination were 0.88, 0.91 and 0.89, and the positive predictive values were 0.53, 0.48 and 0.42 respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of the Validator and the Validation Method on the Outcome of Occlusal Caries Diagnosis

In studies evaluating the performance of caries-diagnostic methods, a validation of the true state of disease is needed. The aim of this study was to evaluate the impact of the validator and the validation system (stereomicroscopy or radiography of tooth sections) on the outcome of diagnostic tests for occlusal caries. The material consisted of 60 extracted third molars which were serially sectioned (500-600 microns thick). Four observers examined the sections by two caries validation methods: stereomicroscopy and film radiography. The presence of caries in the occlusal surfaces of these teeth had previously been recorded by visual inspection and conventional film radiography. The kappa values for interobserver agreement within one validation method ranged from 0.44 to 0.76 for radiography and from 0.47 to 0.60 for microscopy. The intraobserver agreement with the two methods was low (range 0.31-0.49), and by cross-tabulating the data, it was found that the disagreements originated in a consistently deeper lesion score with stereomicroscopy than with radiography by all observers except 1. By use of receiver operating characteristic curve areas, little impact of the validation method was seen when visual inspection was validated (against microscopy mean area = 0.75, against radiography mean area = 0.74). The mean receiver operating characteristic area was higher when diagnostic film radiographs were validated against radiography (0.68) than against microscopy (0.63). The differences between observers within a validation method were larger with microscopy than with radiography. In conclusion, caries validation methods are subject to variability. The outcome of caries--diagnostic tests may be influenced both by the validator and the validation method.

Trends in Caries Prevalence in 5-, 7- and 11-Year-Old Schoolchildren in The Hague between 1969 and 1989

Starting in 1969, periodic cross-sectional examinations of schoolchildren have been carried out in the city of The Hague. In 1989 the periodic examinations were continued and, in general, caries prevalence was found to be very low; D3MFS values ranged between 1.5 and 2.2 at age 11.8 years. Compared to 1984, 5-year-old-children of low and medium socio-economic levels (SES) in 1989 had significantly higher d3mfs values (p less than 0.01), mainly due to a marked increase in decayed surfaces per child; a significant increase in caries experience of the deciduous dentition amongst 7-year-olds of low social level was found (p less than 0.01). A further reduction of D3MFS values for 7-year-old children of low and medium SES could be observed in 1989 compared to 1984. Between 1978 and 1989 a marked D3MFS reductions amongst 11-year-olds in the three social levels was found. Possible explanations for the observed differences in caries experience between 1984 and 1989 are discussed.

Caries Prevalence amongst Schoolchildren in The Hague between 1969 and 1993

Since a first survey in 1969, juvenile caries prevalence in the second largest city of the Netherlands has attained a European minimum of DMFT = 0.8 in 11.9-year-old children. However, the curves of improvement have been flattening out since the mid-eighties. Incidental variations between 1984 and 1993, especially of caries prevalence in the deciduous teeth of 5- and 7-year-old children, do not indicate a turn to the secular downward trend. The stability of juvenile oral health does not seem to be due to changes in dietary habits, nor to public health measures, but is mainly due to good oral health and use of fluoride dentifrices by the children.

Caries Prevalence and Gingivitis in 5-, 7- and 10-Year-Old Schoolchildren in The Hague between 1969 and 1984

In 1969, 1972, 1975, 1978 and 1981 dental examinations have been carried out in The Hague on cohorts of children of kindergartens and elementary schools at the occasion of the start of a long-term dental health education campaign. In 1984 a follow-up part of the cohort examinations was conducted on 5-, 7- and 10-year-old schoolchildren. In 1984 further improvement in dental health of 5-, 7- and 10-year-old children was found. In the 5-year-old children the average d3mfs was 1.61. The average D3MFS scores of the 7- and 10-year-olds were 0.82 and 2.18. Of the 5-, 7- and 10-year-old children 64.6, 73.1 and 41.4% were caries-free. No gingivitis was found in 88.3, 65.7 and 54.7% of the children at 5, 7 and 10 years of age. The percentage of caries-free children during the 15-year period (1969–1984) increased in 5- and 7-year-old children from 1 and 2% to 65 and 73%, respectively. Explanations for the improvement of dental health are discussed.