Caries risk profiles of 12-13-year-old children in Laos and Sweden.

PURPOSE: To analyse caries risk factors of 12-13-year-old children living in Laos, using the computer program Cariogram to illustrate the caries risk profile. In addition, to compare the results with a study performed in Sweden. MATERIALS AND METHODS: One hundred Laotian and 392 Swedish children were included. Interviews were performed to obtain information on diet intake and fluoride use. Saliva was analysed for mutans streptococci, lactobacilli and secretion rate/buffering capacity. Oral hygiene was assessed using the Silness and Löe criteria. Caries prevalence was recorded according to WHO. The data were entered into the Cariogram to determine each child's caries risk, expressed as 'the chance of avoiding caries'. The children were divided into five risk groups. RESULTS: Mean DMFT level of the Laotian children was 4.61 +/- 2.95 and 1.38 +/- 1.97 in the Swedish group. For the risk factors plaque amount, frequency of food intake, saliva secretion rate, buffering capacity and fluoride, the Laotian children had significantly less favourable values compared to the Swedes. Only 6% of Laotian children belonged to the Cariogram low risk group versus 40% of the Swedish children. The mean DMFT for the five Cariogram groups was (from low to high risk) 0.00, 3.00, 3.56, 5.66, 6.11 for the Lao children and 0.31, 1.39, 2.56, 3.03, 2.91 for the Swedish ones. The mean chance of avoiding caries was 37.3% for the Laotians and 69.2% for the Swedish children (p < 0.001). CONCLUSION: According to the 'opinion' of the Cariogram, the Laotian children demonstrated significantly higher caries risk than Swedish children.

Caries risk assessment as a predictor of metabolic control in young Type 1 diabetics.

AIMS: To investigate the relationship between caries risk and glucosylated haemoglobin and to evaluate the use of a computerized caries risk assessment program as a predictor of metabolic control in schoolchildren with Type 1 diabetes mellitus. METHODS: The material consisted of 64 young Type 1 diabetes mellitus patients (8-16 years) attending an outpatient paediatric clinic. Within 2 weeks after the onset of diabetes, a caries risk assessment was carried out with the aid of a computer-based program (Cariogram) and data on the level of metabolic control were collected from the medical records at the 3-year check-up. Caries increment was registered at recall clinical examinations. RESULTS: A statistically significant positive relationship between caries risk and metabolic control was found (r = 0.51; P < 0.01), with a sevenfold increased risk of impaired metabolic control after 3 years in those assessed with high caries risk at onset (OR 7.3; P < 0.01). When the Cariogram was used as a predictor for the metabolic state of the disease, the sensitivity and specificity was 75% and 71%, respectively. The negative predictive value was 91%. CONCLUSIONS: Our data suggested that a caries risk assessment at the diagnosis of diabetes mellitus in children may be a good indicator of overall health care that can provide useful prognostic information on the level of metabolic control after 3 years.

Tracing genotypes of mutans streptococci on tooth sites by random amplified polymorphic DNA (RAPD) analysis.

The aim of this study was to clarify the distribution and persistence of mutans streptococci on different tooth sites in the same oral cavity. Thirteen subjects, aged 20-40 years, were examined. Salivary levels of mutans streptococci, caries prevalence, oral hygiene habits and status of tooth surfaces sampled were recorded. Plaque samples were obtained from four sites, the mesial and buccal surfaces of the first permanent molar on the right side of the lower jaw (46m and 46b), the distal surface of the first permanent premolar (24d) and the mesial surface of the second permanent premolar (25m) on the left side of the upper jaw, using sterile toothpicks on two occasions at 4-7-month intervals. The samples were cultivated on site-specific Strip mutans. Up to 10 colonies/site were isolated when present and genotyped by random amplified polymorphic DNA (RAPD) analysis, after species identification with PCR. Genotyping was also performed by restriction endonuclease analysis (REA) on 148 isolates, and results were consistent with the RAPD results. Most mutans streptococcus-positive samples were obtained from 46m. Within each individual, the same genotype occurred on at least two sites on all but one sampling occasion. A maximum of seven different genotypes were found in an individual. For a particular tooth site, four genotypes occurred simultaneously and taking both sampling occasions together the maximum was six different types. The same genotypes/types were found again after 4-7 months on 25 sites in 12 subjects. Fifteen sites were mutans streptococcus-positive on only one sampling occasion. The results indicate that several different genotypes of mutans streptococci colonize a tooth site, and that the same genotype colonizes several sites in the same oral cavity. Persistence of genotypes on a site for several months and interindividual differences in the occurrence of genotypes were also found.

Evaluation of a computer program for caries risk assessment in schoolchildren.

The 'Cariogram' is an interactive PC program for caries risk evaluation. It takes into account the interactions between caries-related factors and expresses a graphic assessment of the risk. The aim of this study was to assess the caries risk in schoolchildren using the Cariogram and to evaluate the program by comparing the caries risk assessments with the actual change in DMF. A 2-year prospective study on 446 schoolchildren, 10-11 years old, was conducted. At baseline, data on general health, diet, oral hygiene and use of fluoride were obtained. Saliva analyses included mutans streptococci and lactobacilli counts, buffer capacity and secretion rate. DMFT and DMFS were calculated from records and bitewing radiographs. Scores were entered and caries risk was assessed. Re-examination for caries was done after 2 years. The children were divided into 5 groups according to the assessed caries risk at baseline. Where the Cariogram predicted a 0-20% (high risk), 21-40%, 41-60%, 61-80% and 81-100% (low risk) chance of avoiding new lesions, 8, 35, 42, 73 and 83%, respectively, had no new lesions 2 years later. Logistic regression analyses were carried out. When the Cariogram was included, only two factors, the Cariogram (p < 0.001) and the DMFS at baseline, i.e. past caries experience (p = 0.001), turned out to be significantly associated with caries increment. The Cariogram was the most powerful explanatory variable. When the Cariogram was excluded, lactobacillus count, mutans streptococci, diet intake frequency and DMFS at baseline were significantly associated with caries increment. The Cariogram predicted caries increment more accurately than any included single-factor model. How this finding can be translated into daily practice in the best and most practical way is a matter for future research.

Caries prevalence and some caries related factors for 12 year-old children from Vientiane and Luang Prabang provinces in Lao People's Democratic Republic.

Caries prevalence and some caries related factors for 100 twelve-year-old children from Vientiane and Luang Prabang provinces in Lao People's Democratic Republic were studied. The caries prevalence was high showing a DMFT of 4.6 with 9% of the children being caries free, the D comportment contributed mostly to the DMFT and the Significant Caries Index (Sic Index) was DMFT 8.0. As to the caries related factors, 25% of the children were in the high mutans class, 31% of the group had high or very high Lactobacilli scores and 84-88% studied took local sweet snacks, chips and sweet drinks every day. Taking into consideration the high caries prevalence, the mutans streptococci distribution, the frequent intake of sweets and also the relatively low fluoride concentration in the drinking waters, oral health preventive programmes are indicated to prevent a possible caries epidemic in Laos in the future.

Introducing the Significant Caries Index together with a proposal for a new global oral health goal for 12-year-olds.

AIM: To describe a new index, the 'Significant Caries Index' (SiC Index) with the intention of focusing attention on those individuals with the highest caries scores in each population. METHOD: Attention is drawn to the skewed distribution of dental caries within a given population, indicating that there are still large groups of individuals who have considerably more caries than the WHO/FDI target level of DMFT 3 by the year 2000. The index is calculated as follows: individuals are sorted according to their DMFT values. The one third of the population with the highest caries score is selected and the mean DMFT for this subgroup is calculated. This value constitutes the SiC Index. RESULTS: The SiC Index can be easily calculated and used as a measure for future oral health goals. CONCLUSION: The SiC Index should be less than 3 DMFT in the 12-year-olds in a given population and it is hoped that this global oral health goal is reached at the latest by the year 2015.

Caries risk assessment: a comparison between the computer program 'Cariogram', dental hygienists and dentists.

UNLABELLED: The 'Cariogram', which is an interactive PC-program for caries risk evaluation, illustrates the interaction between caries related factors and expresses the caries risk graphically. It also demonstrates a weighted impact of the different etiological factors on the risk. The aim of this paper was to use the Cariogram program on a set of patients, and to compare the outcome of its risk evaluation with those made by dental hygienists and dentists. A questionnaire, containing the descriptions of five patients with detailed information on nine factors generally associated with caries, was given to the participants. They were asked to rank the patients according to their 'chance to avoid dental caries' during the coming year. The results were compared with the assessments obtained from the Cariogram. RESULTS: 73.5% of the dental hygienists and 78.5% of the dentists ranked the patients for caries risk either identically or with only one deviation when compared to the Cariogram. It was concluded that the 'opinion' of the Cariogram on caries risk was in agreement with that of the majority of the participants. In addition, the Cariogram program induced discussions about the relative impact of etiological factors of caries. It is envisaged that the Cariogram can serve as one further tool in the teaching of caries risk.

Genotyping shows different strains of mutans streptococci between father and child and within parental pairs in Swedish families.

The purpose of this study was to investigate whether there was an intrafamilial similarity of mutans streptococcal strains in some Swedish families using chromosomal DNA fingerprinting. Plaque samples were obtained from buccal and occlusal surfaces of 25 three-year-old children, their mothers and 18 fathers. The colonization levels of mutants streptococci were estimated with the "Strip mutans" test, and caries experience was scored by decayed, missing and filled teeth or decayed, extracted and filled teeth. Interviews about medical history, diet regimes, breastfeeding and care of the child were performed. In 11 families isolates of mutans streptococci were detected in all three individuals. These isolates were serotyped by immunofluorescent technique and genotyped using the restriction endonuclease Hae III. The results showed that 5 children harbored mutans streptococci genotypes different from their parents. Six children showed genotypes identical to their mothers. None of the children harbored genotypes similar to their fathers, even though two thirds of the fathers had high or very high mutans streptococci levels. No matching of genotypes was observed within the 11 parental pairs. Mothers as primary caregivers with high "Strip mutans" scores were more often observed in the group with identical genotypes within the mother-child pairs, the "matching group", than in the "no-matching group". These data indicate that the fathers and the children had not acquired each others' strains of mutans streptococci nor had the spouses. The results suggest that the children acquired mutans streptococci both from outside and inside the family.

Immunoglobulin A reaction to oral streptococci in saliva of subjects with different combinations of caries and levels of mutans streptococci.

The aim of this study, performed in Bangkok, was to study whether a particular salivary immunoglobulin A (IgA) antibody profile against mutans streptococci could be related to the absence or presence of caries. A group of 12-year-old individuals representing various combinations of mutans streptococci levels and caries experience was selected. Whole saliva stimulated by paraffin-chewing was collected, and the children were investigated for decayed, missing and filled surfaces (DMFS) and teeth (DMFT), following WHO criteria and methods, at baseline and after 2 years. The total amount of salivary IgA was determined by an immunobead enzyme-linked immunosorbent assay, and SDS-PAGE and Western blot analysis was performed using sonicated antigens of Streptococcus mutans and Streptococcus sobrinus strains and, as a control, a Streptococcus parasanguis strain. The results showed that Thai children with low caries prevalence had more distinct immunoblot bands to antigens from mutans streptococci than did the high-caries children. A similar picture was not seen for S. parasanguis. On the whole, the Thai children also showed fewer bands than usual Swedish saliva samples from comparable age groups. The complexity of the relationship between dental caries and IgA in saliva is highlighted.

Reasons for the caries decline: what do the experts believe?

The aim of this paper was to describe what experts of today believe are the main reasons explaining the caries decline seen in many westernized countries over the past 3 decades. We have collected the views of a number of international experts, trying to answer the specific question "What are the main reasons why 20-25-year-old persons have less caries nowadays, compared to 30 years ago?". A questionnaire was mailed to 55 experts with a number of thinkable explanations to be scored according to a predetermined scale. The 25 items were divided into main groups under the heading of diet, fluorides, plaque, saliva, dentist/dental materials and other factors. The experts were asked to think of a specific country or area, and also to specify whether the chosen area had water fluoridation or not. The main finding of our study, based on a 95% response rate, was that there is a very large variation in how the experts graded the impact of various possible factors. For the use of fluoride toothpaste, there was a clear agreement of a definite positive effect.

The caries decline: a review of reviews.

The aim of this paper is to review publications discussing the declining prevalence of dental caries in the industrialized countries during the past decades, focusing on some main conferences addressing this issue. Has there been a real decline in the prevalence of dental caries? Several excellent papers and reviews have been published, and there is a general agreement that a marked reduction in caries prevalence has occurred among children in most of the developed countries in recent decades. This fact has stimulated much debate and attempts to identify the most likely explanations for this change. The conclusion made from this review is that the various authors believe that the use of fluoride in various forms has contributed most significantly to the decline in dental caries prevalence. A number of other factors must, however, also be taken into consideration, and such factors have been extensively discussed in the various publications.

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.

Dental caries: intervened--interrupted--interpreted. Concluding remarks and cariography.

This paper comprizes a summarizing discussion for a set of 13 papers on the theme caries decline. The complexity of the issue is highlighted, and it is concluded that there is not one single factor explaining the changes observed. Actually, in one and the same population, different explanations may be relevant for different individuals, for different age groups, for different teeth and for different periods of time. A new model for understanding the interaction of various caries etiological factors is proposed. The model can illustrate how in one situation caries activity can increase (or decrease) due to one such factor, while in another situation different factors are more important. As it, in a graphic way, maps the interactions of relevant factors, the author has chosen to call it a cariogram, and the process of preparing such graphs, cariography.

Evaluation of a simplified method for site-specific determination of mutans streptococci levels.

To determine the oral mutants streptococcal "load" of an individual, saliva samples reflecting the number of colonized tooth surfaces, are often applied. Sometimes a plaque sample from a specific site would be an advantage, for example in connection with local antimicrobial treatments. The aim of the present paper was to evaluate a chairside method for determination of mutans streptococci interproximally. One hundred subjects participated. Four approximal tooth surfaces of each individual were sampled using toothpicks. The toothpicks were then let to contaminate a pad on a specially designed plastic strip and, for comparison, a MSB-agar plate. The strips were incubated in the standard "Strip mutans" broth. The yield of colony forming units on the strip surface corresponded significantly with that on agar plates. Being a simple chair-side method for the evaluation of the site-specific load of mutans streptococci, it is suggested that the method will be used in various investigations to clarify its potential in different clinical situations.

A study into the prevention of fissure caries using an antimicrobial varnish.

The aim of this study, performed in Bangkok, was to evaluate the possibility of reducing fissure caries development using an antimicrobial varnish, Cervitec. Children aged 7-8 years and 12-13 years, 251 in each age group, with at least 2 sound contra-lateral permanent molars, were selected. A split mouth method was used with one test and one control tooth within the same jaw. At baseline and after two years all children were investigated for DMFS and DMFT. In addition, the size of any cavities was estimated. From 200 children, plaque samples of test and control occlusal surfaces were collected at baseline and after one year and processed to estimate the number of mutans streptococci. Mutans streptococci in saliva were estimated by the Strip mutans method. Cervitec varnish, containing 1 per cent chlorhexidine and thymol was applied at baseline, after 3-4 and after 8-9 months. The results showed that: Cervitec varnish reduced fissure caries development significantly; the levels of salivary mutans streptococci at baseline were significantly correlated with caries status at baseline and with total caries increment over the two-year period; caries development in a fissure was significantly correlated to the level of plaque mutans streptococci at that same site; three months after the last varnish application, a certain reduction of mutans streptococci in plaque could be seen in the test teeth; comparing the size of the lesions, more large cavities were found in the untreated teeth. It is concluded that varnishes should be considered as further options for prevention of fissure caries, possibly in more individualised programmes or in combination with already established methods.

Adding fluoride to sugar--a new avenue to reduce dental caries, or a "dead end"?

A study group was formed in 1989 by the Oral Health Program of WHO, Geneva, to consider the possibility of reducing dental caries by adding fluoride to sugar. Although a few promising clinical reports were available for review, the group found that information was too scarce for field trials to be recommended at this stage. Among the many items to be considered was what concentration of fluoride in sugar could reasonably be regarded as cariostatic. Thus, the committee decided to initiate studies to obtain further background information. Unlike fluoridated salt, the concept of fluoridated sugar does not involve trying to give the individual a certain daily amount of fluoride, since daily consumption varies considerably. Instead, the idea is to elaborate on recent fluoride research showing that low concentrations of fluoride may also be beneficial, particularly for remineralization, if present at the sites where caries occurs. This paper is an introduction to a set of papers describing the background for the project, attempting to define optimal concentrations for a clinical trial, and concluding that, although dental caries prevalence continues to decrease in industrialized countries, the potential for large increases remains in the huge populations in developing countries. All avenues must be searched for a system which optimizes preventive efficiency. However, the possible introduction of fluoridated sugar on the market is not related only to oral health. Safety aspects are of high priority, and several ethical, political, and economic factors must also be considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrafamilial similarity in immunoblot profiles of salivary immunoglobulin A antibody activity to oral streptococci.

Analysis of the salivary immunoglobulin A (IgA) antibody activity to antigens separated from oral streptococci was carried out on 49 individuals in 11 families. The aim of this study were to i) study the human salivary IgA activity within families to antigens separated from reference strains of Streptococcus mutans, Streptococcus sobrinus and Streptococcus parasanguis and ii) to search for potential differences in the salivary IgA activity to the streptococcal antigens several years apart. The immunoblot revealed similarity in saliva IgA response within the families. A majority of the bands, approximately 7 (median) for each extract was found in both child and parent. A few bands (approximately 3) were found in parents but not in children. Only one to two bands were found in children's saliva without a corresponding band in any of the parents. The antibody activity of saliva samples obtained several years apart was essentially unchanged, especially considering the total number of bands. Differences in the relative intensity of the bands could be seen, and a few bands appeared only in some immunoblots for a specific subject. For 3 of 4 children participating in the longitudinal study, more bands against mutans streptococci appeared with age.

Effects of glass ionomer cement, resin-based pit and fissure sealant and HF applications on occlusal caries in a developing country field trial.

The aim of this community-oriented study was to evaluate different methods to prevent fissure caries. The following products and measures were tested: 1) glass ionomer cement (GIC) applied by dentist; 2) same material applied by short term (3 days) trained personnel (teachers); 3) application of a 0.5% HF solution three times; 4) an established autopolymerized resin based sealant (Delton). The study was performed in Bangkok, Thailand, a city in a developing country experiencing increasing caries prevalence. Children with at least three sound permanent molars from two age groups, 7-8 and 12-13-yr-olds respectively were chosen from very low to medium socioeconomic level families. 1264 children were systematically assigned to experiment or control groups based on school and DMFT. For the younger age group, the 2 yr mean DFS occlusal increment in the Control group was 0.66 surfaces. Significantly lower increments were observed in the GIC experimental group: 0.17 surfaces applied by the teachers and 0.32 applied by dentist, corresponding to 74% and 52% reductions, respectively. The mean increment in the HF group was 0.44 surfaces, a 33% reduction in relation to the Control group. For the 12-13-yr-olds, the mean occlusal surface DF increment was 0.70 surfaces in the Control group. Almost no occlusal increment was found in the Delton group, 0.05 DFS, a 93% reduction. In the GIC Dentist group, the DFS increment was 0.48 and in the Teacher group 0.56, corresponding to 31% and 20% reduction, respectively. A slight and nonsignificant increase of caries in relation to the Control group was observed in the HF group.(ABSTRACT TRUNCATED AT 250 WORDS)