A survey of dental caries in Iceland

Caries prevalence of permanent teeth: a national survey of children in Iceland using ICDAS

OBJECTIVES

The Icelandic Oral Health Survey aimed to obtain new national data on the oral health of Icelandic children and teenagers.

METHODS

A representative stratified random cluster sample of 2251 Icelandic children in first, seventh and 10th grade, aged approximately 6-, 12- and 15-years old was examined for caries prevalence using the ICDAS criteria. Bite-wing digital radiographs were obtained for the children in 7th and 10th grade.

RESULTS

D(3)MFT scores by visual examination of 6-, 12- and 15-year olds were 0.12, 1.43 and 2.78 respectively but when including radiographs, the D(3)MFT rose to 2.11 at 12 years and 4.25 at 15 years. The Significant Caries Index, SiC, by visual examination for 12 and 15 y was 3.7 and 6.7 respectively but was 4.7 for 12 y and 8.9 for 15 y with radiographs. In all age groups and at most disease levels, caries was active in the majority of the lesions (58-100%). The percentage of children with no visually detectable caries at D(3)/D(1) level was 93%/74% for 6 years, 48%/22% for 12 years and 35%/16% for 15 years. When radiographs were included the percentage reduced to 34%/15% for 12 years and 20%/6% for 15 years. Approximately 80% of 12- and 15-year-olds had at least one of their first molars sealed, with the mean number of sealed first molars being 2.2 among 12 y and 2.0 among 15 y.

CONCLUSIONS

Caries levels were higher than expected in this national survey and further away from the goals of the National Health Plan for 2010 than anticipated. Caries distribution was skewed with more than half of the children having low caries scores but a wide distribution of caries experience was seen among the remaining population.

Restoring oral health. On the rise and fall of dental caries in Iceland

During the last decade, a continuous decrease in dental caries has been observed among schoolchildren in Iceland. In this paper, various epidemiological studies have been reviewed and summarized to illustrate caries prevalence, and how it has changed during the last decades. Furthermore, an attempt has been made to describe some of the factors involved and their possible effects on caries disease. During this period, sugar consumption increased, especially in the form of sweets and soft drinks. At the same time, the import of toothpaste increased, and preventive measures such as fissure sealants and fluoride rinsing programs were intensified. Other factors likely to have had an impact were changes in treatment philosophy and increased personnel resources. There does not seem to be any single factor responsible for the onset of the caries decline. It rather looks as if this was a multifactorial effect due to a number of different preventive measures. During recent years, a change in treatment philosophy, the evident increase in fluoride toothpaste consumption, and possible changes in the oral microbial flora, together with the use of fluoride varnishes, sealants, and increased manpower, may explain the decline.

Edentulousness in Iceland in 1990. A national questionnaire survey

Levels of edentulousness were established for seven age groups by means of self-administered questionnaires. The percentage of edentulousness in the Icelandic adult population (18 years and over) was 20.7%. Edentulousness was first reported in the 35- to 44-year-olds and increased rapidly with age. Women had a higher level of edentulousness than men, and the percentage of edentulous people in Reykjavík was significantly lower than in towns, villages, and rural areas. The proportion of edentulous 35- to 44-year-olds and those 65 years old or older was significantly lower than in a similar study in 1985. The percentage of 18- to 79-year-old edentulous Icelanders in 1990 decreased considerably from the results of a national survey on oral health performed in 1962, mainly as a result of a major reduction of edentulousness in the younger age groups and among women.

Longitudinal study of caries, cariogenic bacteria and diet in children just before and after starting school

Fifty 5-yr-old preschool children living in Akranes, a small community in West Iceland known to have a high caries prevalence, were investigated with respect to caries, salivary counts of mutans streptococci and lactobacilli, and consumption of cariogenic foods. Fifteen months later, after being in school for half a year, 43 of the 50 children were reexamined and investigated as before. Mean dmfs scores rose from 7.1 to 9.0, but the scores including initial caries rose from 9.7 to 15.3. Mutans streptococci were carried by 84% of children on both occasions with a mean count 2.1 and 3.6 x 10(5) cfu/ml. Lactobacillus carriage increased from 29 to 38% and the mean count from 5.1 to 13 x 10(3) cfu/ml at 6 yr. The frequency of consumption of sugar-containing foods increased from 4.2 to 5.2 intakes per day and between-meal snacks rose from 3.0 to 3.7 per day. Children classified as "misusing" sugar were 59% at 5 yr and 83% at 6 yr. The mean caries score at 6 yr for children "misusing" sugar was 10.7 but only 2.0 for those not misusing sugar. Thus the deterioration in dental health appears, in these children, to be associated with the increased consumption of sweets and other cariogenic between-meal snacks after starting school.

Dental caries and Streptococcus mutans in a rural child population in Iceland

In spite of having a high socioeconomic standing, in Iceland caries prevalence has remained stubbornly high. This study reports findings from a mixed fishing and farming community in East Iceland that has traditionally been associated with the highest prevalence of caries. A total of 188 children aged 3-16 yr (96.4% of residents of that age group) were examined. At 6 yr the mean dmfs score was 4.1, DMFS 0 and 48% were caries-free. The mean DMFS score at 12 yr was 4.7 and 22.6% remained caries-free but at 16 yr the DMFS score was 11.6 and no children were caries-free. Caries was unevenly distributed within each age group and was more prevalent among residents of the fishing town than the surrounding farming district. In a pilot study conducted in 1989 mean counts of Streptococcus mutans for children aged 4-7 yr were 2.6 x 10(5) cfu/ml and declined to 4.6 x 10(4) cfu/ml in 1990 after a program of chlorhexidine brushing had been added to the routine caries preventive measures adopted in this community. It may therefore be possible to screen Icelandic children for caries risk and apply preventive measures to those demonstrated to be most in need.

Caries prevalence in Icelandic children in 1970 and 1983

In the autumn of 1983 a clinical survey was carried out on 756 children aged 6-14 yr, residing in three non-fluoridated communities in Iceland. The aim of the survey was to assess what changes, if any, in caries prevalence may have taken place as a result of the provision of free dental restorative services for these children since 1974. The 1983 prevalence data were compared with data obtained from a caries survey conducted in 1970 in the same areas in Iceland. The same examiner performed all examinations in both studies. Although considerable increase was noted in number of filled teeth with a corresponding decrease in carious and missing teeth, a statistically significant change in caries prevalence, (dft, dfs, DMFT, DMFS) did not manifest itself. The dfs and DMFS in 1983 was 8.9 and 9.5, respectively, compared to 8.5 and 10.4 in 1970. Over 90% of the toothpaste used in Iceland during the 1970's contained fluoride. The children in the three study areas had not been provided with any public preventive programs.

Comparative epidemiology of multiple sclerosis and dental caries

The geographical distribution and other epidemiological characteristics of multiple sclerosis (MS) are compared with those of dental caries. The rates of death due to MS in Australian states are linearly related to the numbers of decayed, missing, and filled (DMF) teeth found in individuals from those states (r=0.97, P less than 0.002). In the United States of America, a strong positive correlation (r=0.55, P less than 0.001) also exists between MS death rates and dental caries indices. The prevalence of MS in 45 countries or areas correlates well with the frequencies of DMF teeth among children of school age in those locations (r=0.78, P less than 0.001). The prevalence of MS also correlates well with the percentage of edentulous individuals in certain countries (r=0.99, P less than 0.001). A review of the literature shows that the risk for dental caries is lower among the following groups: the lower socioeconomic classes in the United States of America; Chinese immigrants to England compared with natives; blacks compared with whites; and males compared with females. The dental caries risk is higher during pregnancy and lactation. All these trends have been described for MS as well. It is suggested that dental caries may be a more accurate epidemiological model for MS than poliomyelitis. It is also suggested that MS and dental caries may share certain aetiological factors, two of which may be dietary excess of certain fats, and vitamin D deficiency.