A four-year cohort study of caries and its risk factors in adolescents with high and low risk at baseline

AIM: To report and compare risk and preventive factors for caries in high- and low-risk adolescents, from a 4-year cohort study on commonly used preventive measures for caries in adolescents in the Swedish Public Dental Service. SUBJECTS AND METHODS: In 1995 a cohort of 12-year-olds was examined for caries and completed a questionnaire. This procedure was repeated at age 14 and 16. The group identified as being at high risk was examined every year and this group was randomly assigned to one of four preventive programs. The outcomes examined were the caries increments using the DMF-indices. Poisson regression was used to assess risk and preventive factors. RESULTS: The number of 12-year-olds participating was 3,373 in 1995 and 2,848 were still participating in 1999. A higher risk of caries increment was observed for adolescents from working-class homes, from outside Western Europe, and for those who often ate candy and did not brush their teeth twice a day. Important findings were the different results for the preventive factors when different DMF-indices were used as outcome measures and the fact that there was no difference between the high-risk group and the total group when it came to risk or preventive factors. The clinically tested prevention had a low effect i.e., the semi-annual application of fluoride varnish prevented 10% of the dentine and enamel caries development over 4 years.     

On caries prevalence and school-based fluoride programmes in Swedish adolescents

Dental caries on approximal tooth surfaces in adolescents is still a problem in Sweden, as well as in many other industrialised countries. The aims of the present thesis were therefore: 1) to study whether caries prevalence is underestimated, 2) to evaluate the effect of cessation of fluoride mouth rinse (FMR) programme in schoolchildren with low caries prevalence, and 3) to reconsider the school as an arena for population-based fluoride (F) varnish and FMR programmes in order to minimise caries development in 13-16-year-olds. Paper I and II showed that the adolescents' own dentists consistently registered less caries compared to the recordings made by calibrated dentists from outside. Based on 420 16-year-olds at 12 different dental clinics in two neighbouring counties in Sweden, the differences were statistically significant at 10 of the 12 clinics when caries prevalence both was high in 1984 (Paper I) and somewhat lower in 1987 and 1990 (Paper II). About 80% of all approximal caries lesions were enamel lesions and are therefore not reported to the Swedish authorities, as only dentin lesions and fillings are currently included in the official caries data. The basis for Paper III was that many counties in Sweden abandoned school-based FMR programmes in the mid-late 1980s, as the official caries data revealed low caries prevalence among children. The cessation of FMR for 3 years for a group of 13-16-year-old adolescents (n=60) with low caries prevalence did not reveal any statistically significant differences in new caries lesions and fillings or in the progression of existing enamel lesions compared to a group of 13-16-year-olds (n=60) who continued to rinse for 3 years. Nor did a supplementary cross-sectional study reveal any differences in caries prevalence among adolescents who had or had not taken part in FMR programmes for the last 3 years. In Papers IV and V, new models for school-based F treatment were evaluated in two 3-year randomised controlled trials (RCT studies). Fluoride varnish (Duraphat) treatment, carried out at school by specially trained dental nurses using a simple mobile unit, among 854 13-16-year-olds from low, medium and high caries risk areas showed that the control groups developed more caries than the varnish groups (Paper IV). The largest difference was found in the high-risk area. The prevented fraction (PF) with approximal enamel lesions as the diagnostic threshold was 69% in high, 66% in medium and 20% in low risk areas for F varnish applied twice a year at six-month intervals. Supervised school-based FMR among 788 13-16-year-olds with low to moderate caries risk (Paper V) showed that FMR on the first three and the last three school days during the school term, i.e. 12 rinses/year, had a PF of 59%. Enamel lesions constituted > 90% of the new approximal caries lesions in both Papers IV and V. The main conclusions from this thesis are: (1) that enamel caries lesions on approximal surfaces should be included in epidemiological caries data in order to show true caries prevalence, (2) that the cessation of weekly FMR for 3 years did not lead to a statistically significant increase in caries incidence in a relatively small group of adolescents with low caries prevalence, and (3) that the school should be reconsidered as an arena for new models for population-based F school programmes. Fluoride varnish treatment twice a year at six-month intervals in medium and high caries risk areas, as well as supervised FMR on the first and the last three school days during the school term in low and medium caries risk areas, are excellent caries prevention strategies for approximal surfaces in adolescents at the caries risk ages of 13-16 years, as a supplement to dental home care and preventive efforts at dental clinics.     

A randomised controlled trial of the caries-preventive efficacy of a chlorhexidine-containing varnish in high-caries-risk adolescents

A professionally applied two-stage chlorhexidine varnish, Chlorzoin((R)), was developed to achieve sustained release and minimise the problems of staining and bad taste associated with chlorhexidine mouthrinses. The primary aim of this randomised controlled clinical trial was to assess the efficacy of Chlorzoin in reducing the caries increment in high-caries-risk adolescents. Secondary aims included investigating the effect of compliance upon caries increment, the effect of Chlorzoin upon salivary mutans streptococci levels and assessing the benefit of individual dental health advice by dental auxiliaries in a community setting. 1,240 children, initially aged 11-13 years, assessed to be at high caries risk were recruited into the trial. The trial design involved four arms: an observational group, a control group, an active (Chlorzoin) varnish group and a placebo varnish group. All subjects were examined annually by a calibrated examiner who was blind to the group allocation. Three-year caries increments were calculated using clinical, clinical and fibre-optic transillumination, and clinical and bitewing data sets. The results indicated that the use of Chlorzoin had an initial effect on mutans streptococci levels but that no long-term reduction in caries increment or mutans streptococci infection could be detected. One reason for this lack of efficacy may have been the regimen of reduced frequency of varnish applications after the initial period. Children who followed the protocol and, therefore, were seen regularly by dental auxiliaries had a lower caries increment than those who did not. This finding was independent of varnish allocation. In summary, under this regimen, Chlorzoin has been found to be effective in decreasing salivary mutans streptococci but ineffective as a caries-preventive agent in high-risk Scottish children when applied pragmatically in a community setting.     

Caries prevention with fluoride varnish in a socially deprived community

It has been suggested that specific preventive programs be developed for children with high caries risk. One possibility is to consider whole classes in socially deprived schools as caries-risk groups and perform an intensified preventive program for the entire class. OBJECTIVE: The purpose of this study was to evaluate the effectiveness of such a program which includes the application of a fluoride varnish (Duraphat). METHODS: The application of the varnish was offered three to four times a year in a community with low socio-economic status and a generally high caries level. Two hundred and sixty-nine children in six primary schools of Linden/Limmer, a district in Hannover, Germany, were allocated to a test or a control group. The test group received the fluoride varnish for 4 years whereas the control group received no professional fluoride application. DMFT was recorded at the beginning of the study and after 4 years. RESULTS: At the end of the study, children who had received a minimum of two fluoride applications per year showed a significantly lower caries increment in comparison with the control group (0.88 DMFT vs 1.39 DMFT, P < 0.05). CONCLUSIONS: It can be concluded that a minimum of two applications of the fluoride varnish Duraphat per year may be an effective measure in preventing caries in socially deprived children with high caries activity.     

Evaluation of caries preventive measures

This article describes the aims, methods and baseline results of a project evaluating preventive measures within a selected high-risk group. In 1995 a cohort of 3373 12-year-olds was examined with regard to caries. A high-risk group was identified and randomly divided in four different groups, receiving different preventive programs. The whole study group will be examined every other year until the adolescents are 18 years old. The high-risk group will be examined every year and given the four different preventive measures until the adolescents are 18 years of age. A questionnaire will be answered by the adolescents every other year, in order to learn more about the links between demographic data, social background, lifestyle and health behaviour. Analysis of baseline results showed that the social distribution of the study group is comparable to that of the background population as well as to the distribution in rural and urban areas. The mean DMFT was 1.5, which is in accordance with the national figure. The 28 dentists who collect the data and perform the caries diagnostics were calibrated and the mean inter- and intra-reproducibility was 0.78 and 0.82, respectively. In conclusion, it seems that the study group is representative of 12-year-olds in Sweden; thus, inferences drawn from the results of the project may be valid for adolescents in Sweden as a whole.     

Cost-effectiveness of different caries preventive measures in a high-risk population of Swedish adolescents

OBJECTIVES: A total of 3373 12-year-olds agreed to participate in an intervention study evaluating different caries preventive measures. The study, titled 'Evaluation of caries preventive measures', was performed between 1995 and 1999 at 26 dental health clinics throughout Sweden. At the start of the study, the subjects were classified as individuals at high or low risk of developing caries. The high-risk group consisted of 1165 subjects. The children in the high-risk group were randomly assigned to one of four preventive programs. The programs represent a step-wise increase in fluoride content, contact with dental personnel and cost. The aim of the present cost-effectiveness analysis (CEA) study performed from a societal perspective is to compare costs and consequences of caries preventive programs in a caries high-risk population. By 'costs' is meant both treatment costs and costs contributed by the patient and the patient's family. Costs contributed by patients and their families consist of out-of-pocket expenses, transportation costs, and time. Conclusions are that it is important to consider the perspective from which a study is carried out. Costs contributed by the patient and the patient's family have a high impact on total costs for children and younger adolescents but decrease with time as the adolescents get older. The present study shows an incremental cost-effectiveness of 2043 SEK (8.54 SEK = 1 US dollar, December 1999) per averted decayed enamel and dentine missing and filled surface (DeMFS), of which treatment costs represent 1337 SEK using the unit cost for a nurse. This means a yearly cost of approximately 334 SEK.     

Effect of flouride varnish (Duraphat) treatment every six months compared with weekly mouthrinses with 0.2 per cent NaF solution on dental caries.

Recent studies have shown a high fluorine uptake in the enamel and a considerable caries reduction following the application of varnished containing fluoride. As the application is easy to carry out it may in certain situations serve as an alternative to other topical fluoride school programmes. The aim of the present study, therefore, was to compare the caries increment in schoolchildren exposed to a fluoride varnish (Duraphat) every six months and in children receiving the conventional weekly fluoride mouthrinsing programme with 0.2 per cent sodium fluoride over a two-year period. Two hundred 14-year-old children, divided into one test and one control group took part in the study. They were clinically and radiographically examined every year. Preexperimental data revealed no differences between the groups. During the experimental period the children in the fluoride varnish group developed a statistically significant lower number of new carious lesions compared with those in the mouthrinsing group. The difference in caries increment was about 30 per cent. Further clinical studies to compare the effects of various topical fluoride programmes are recommended.     

含氟涂料与含氟泡沫对儿童龋病预防效果的对比研究

目的比较含氟涂料和含氟泡沫对儿童乳牙龋病的预防效果,为在我国开展乳牙龋病防治工作提供理论依据。方法随机整群抽样的方法抽取2所幼儿园的3~4岁儿童共220名,进行口腔检查,记录患龋情况。随机将这些儿童分为含氟泡沫组和含氟涂料组,分别用氟泡沫和氟保护漆进行龋齿预防,每半年1次,2年共干预4次,每年进行口腔检查,比较2组基线后1年和2年的乳牙新生龋均、新生龋面均及龋齿发病率。结果含氟泡沫组干预1年及2年后新生龋面均分别为2.58±4.36、3.85±5.15;含氟涂料组干预1年及2年后新生龋面均分别为0.95±2.28、1.94±3.32,均显著低于含氟泡沫组(P<0.01)。结论含氟涂料对儿童龋病的预防效果优于含氟泡沫。     

The role of extended duties dental nurses in applying fluoride varnish for the prevention and control of dental caries

The role of extended duties dental nurses (EDDNs) in undertaking preventive dental care has provided an opportunity for their direct involvement in patient care, both at an individual patient level and as part of a population wide health improvement initiative. The article describes the developing role of the dental nurse in the clinical application of fluoride varnish, with associated evidence of effectiveness for the prevention and control of dental caries. The use of fluoride varnish as being central to caries preventive programmes for individual patients judged at risk of future dental caries is considered. A Scottish dental public health initiative which utilizes these extended skills and the benefits of fluoride varnish application is described. CLINICAL RELEVANCE: This paper illustrates how EDDNs can help to foster a greater team approach to overall patient care and preventive practice by applying fluoride varnish as part of an effective caries preventive programme.     

Effect of school-based fluoride varnish programmes on approximal caries in adolescents from different caries risk areas

The aim was to evaluate, in a 3-year RCT study, school-based fluoride varnish programme on approximal caries incidence and approximal caries progression in 13- to 16-year-olds in high, medium and low caries risk areas on the Swedish west coast. Seven hundred and fifty-eight (89%) fulfilled the trial. Using a simple mobile unit, 2 dental nurses treated the adolescents with F varnish: (1) twice a year at 6-month intervals, (2) 3 times a year within 1 week, (3) 8 times per year during the semesters with 1-month intervals, and (4) no treatment (control). Radiographic caries recording was performed blindly by one of the authors. Concerning total approximal caries incidence, control groups in all areas developed more caries than F varnish groups, with the largest difference in the high risk area: 3.05 +/- 3.37 new approximal caries lesions (mean +/- SD) compared to 0.54 +/- 1.26 for group 3, 0.95 +/- 1.67 for group 1 and 1.40 +/- 1.89 for group 2 (p < 0.001). More than 90% of the new approximal lesions in all the groups and in all areas consisted of new enamel lesions. Regarding progression of enamel lesions, there were only significant differences between groups 1-3 and group 4 in the high caries risk area. Prevented fraction for fluoride varnish treatment twice a year at 6-month intervals was 69% in high, 66% in medium and 20% in low risk areas. To conclude, school-based F varnish treatment every 6 months in 13- to 16-year-olds is excellent to prevent approximal caries in medium and high caries risk areas.     

Recommendations for fluoride varnish use in caries management

Available data suggest that fluoride varnish can be a safe and effective method for caries management. The application of varnish can be beneficial for those at risk for caries and for patients with special needs, and for those with no access to daily fluoride or other preventive methods. Even a small amount of varnish can be applied to active noncavitated lesions, assuring that a high concentration of the agent is available at the site where needed and that the total amount of active agent administered to the patient may be markedly reduced. Considering that varnish treatment is painless and can be easily performed by auxiliary dental personnel, it is a caries preventive method that can be easily applied and recommended for any age group, even young children. For high-risk caries patients with a significant cariogenic challenge, topical applications of fluoride might be insufficient and thus could be supplemented with other anticariogenic methods, such as xylitol chewing gum.     

Evaluation of preventive treatment by risk of caries among 13-year-olds

Abstract Implementation of caries preventive treatment in relation to the risk of caries was studied among 13-year-olds (n=132) in two groups treated in the same public dental clinics in Helsinki: caries patients (n=100) had the greatest numbers of decayed teeth (DT+dt), 5.5 on average, whereas cavity-free patients (n=32) had intact teeth. Data taken from patients' personal oral health records served for evaluation of individual need for caries prevention, risk of caries, and preventive treatment given to each patient. Patients with any caries lesions or erupting teeth or poor oral hygiene were considered to be at risk of caries and in need of preventive treatment. The more caries lesions a patient had, the more prevention was expected to have been given. Preventive treatment of caries was weakly or only moderately in accordance with patients' individual needs and risk of developing caries, although patients with more caries lesions tended to have been given more preventive treatment than did those with none or only a few lesions. The majority of preventive measures given were applications of fluoride varnish, whereas motivation of and instruction in oral health care habits remained weak. However, patients whom their dentists had judged to be at high risk of caries received more intensified preventive treatment than did other caries patients. As a conclusion, intensification of caries prevention among high-risk patients is still needed. Dentists should always consider each patient's risk of developing caries to improve quality of preventive treatment.     

Effect on caries of different fluoride prophylactic programs in preschool children. A two year clinical study

376 three-year old children were divided into four experimental groups and exposed to different combinations of preventive programs for a period of two years. All the groups were given the same basic prophylactic information. Additionally Group I received fluoride tablets (FLUDENT) for daily sucking twice a day plus a placebo dentifrice free of fluoride. Group II was given a fluoride dentifrice containing 0.025% F, (ACTA). Group III was given a placebo dentifrice plus fluoride varnish (Duraphat) twice a year. Group IV a fluoride dentifrice containing 0.025% F (ACTA) plus fluoride varnish (Duraphat) twice a year. No statistically significant difference in caries increment during the two experimental years was found between the groups. A tendency to lower caries increment was found in Group IV, i.e. in the children using the low fluoride dentifrice and treated twice a year with fluoride varnish.     

欧卡芙氟保护漆A型与多乐氟氟化钠护齿剂预防学龄前儿童龋病的效果对比

目的:比较欧卡芙氟保护漆A型与多乐氟氟化钠护齿剂预防学龄前儿童龋病的效果。方法:选取我市3岁儿童520名,随机分为3组,欧卡芙氟保护漆A型组(176名)和多乐氟氟化钠护齿剂组(174名)分别给予全口乳牙涂布该药物,空白对照组(170名)仅进行口腔卫生宣教。对比分析3组儿童干预前后患龋情况。结果:干预前3组儿童的患龋率及龋齿数差异均无统计学意义(P>0.05)。干预1年后,欧卡芙氟保护漆A型组患龋率、新增患龋人数均低于多乐氟氟化钠护齿剂组和空白对照组(P<0.05)。结论:两种药物均能防龋,欧卡芙氟保护漆A型防龋效果优于多乐氟氟化钠护齿剂。     

Caries frequency in permanent teeth before and after discontinuation of water fluoridation in Kuopio, Finland

Abstract– The piped water of Kuopio, Finland, was fluoridated in 1959. Owing to strong opposition by different civic groups, water fluoridation was stopped at the end of 1992. Objectives: The aim of this study was to examine the consequences of the discontinuation on dental health. Methods: In 1992 and 1995, independent random samples of all children aged 6, 9, 12 and 15 years were drawn from Kuopio and Jyväskylä, a nearby low fluoride town whose distribution of demographic and socio-economic characteristics was fairly similar to Kuopio's. The total number of subjects examined was 550 in 1992 and 1198 in 1995. Caries was registered clinically and radiographically by the same two calibrated dentists in both towns. Results: In 1992, the mean DMFS values were lower in the fluoridated town for the two older age groups, the percentage differences for 12- and 15-year-olds being 37% and 29%, respectively. For the two younger age groups no meaningful differences could be found. In 1995, the only difference with possible clinical significance was found in the 15-year-olds in favor of the fluoridated town (18%). In 1995, a decline in caries was seen in the two older age groups in the nonfluoridated town. In spite of discontinued water fluoridation, no indication of an increasing trend of caries could be found in Kuopio. The mean numbers of fluoride varnish and sealant applications decreased sharply in both towns between 1992 and 1995. In spite of that caries declined. Conclusions: These findings suggest that the decline of caries has little to do with professional preventive measures performed in dental clinics.     

Change in caries prevalence after implementation of a fluoride varnish program

Objective : In 1996 the caries prevalence of schoolchildren living in Neukölln, a district of Berlin, Germany, was higher than the mean of total Berlin. Hence, a special preventive program including the application of fluoride varnish was initiated. All 49 primary schools of the district joined the project. The aim of the present study was to evaluate in a cross‐sectional study whether the preventive program resulted in a reduced caries prevalence. Methods : The complete program included oral health education as well as the application of a highly concentrated fluoride varnish (Duraphat®). All children whose parents' consent was given could receive fluoride varnish twice a year. All children were examined once a year by four calibrated dentists. The baseline examination was conducted in 1995–96, the final examination in 1999–2000 (1995–96: n= 7,748; 1996–97: n= 15,673; 1997–98: n= 19,362; 1998–99: n= 19,822; 1999–2000: n= 17,984). Results : A total of 80,589 dental records were used for data analysis. A decline of DMFT‐values was observed in all age groups and school years. The major improvement was found in school year 1999–2000, when the program had been established for four years. Conclusion : The described program may be an effective public health measure for 6‐ to 12‐year‐old children with high caries prevalence.     

Caries incidence in adolescents with low caries prevalence after cessation of weekly fluoride rinsing

The aim of this study was to determine whether cessation of weekly fluoride rinsing leads to an increase in caries incidence in a group of adolescents with low caries prevalence. Sixty randomly selected 12- to 14-year-olds were asked to stop rinsing at school (test group). After 3 years caries increment and caries progression were compared with an age- and sex-matched control group (n = 60), who continued to rinse weekly with a 0.2% sodium fluoride solution. All children in both groups had followed a school-based fluoride rinsing program from the age of 6 years. The mean (standard deviation) caries increment, including only open lesions, during the 3 years was 1.58 (1.73) in the test group and 1.48 (1.80) in the control group. The corresponding figures for incipient lesions were 3.13 (3.63) and 4.03 (4.23), respectively. The mean caries progression was 0.92 (1.34) in the test group and 0.72 (1.03) in the control group. None of these differences were statistically significant. Thus, this study showed that a cessation of weekly fluoride rinsing did not lead to an increase of caries incidence in a group of adolescents with low caries prevalence.     

Noninvasive control of dental caries in children with active initial lesions. A randomized clinical trial

The aim of this study was to investigate whether DMFS increment can be decreased among children with active initial caries by oral hygiene and dietary counseling and by using noninvasive preventive measures. Except for mentally disabled and handicapped children attending special schools, all 11- to 12-year-olds in Pori, Finland, with at least one active initial caries lesion were invited to participate in the study and were then randomized into two groups. Children in the experimental group (n = 250) were offered an individually designed patient-centered preventive program aimed at identifying and eliminating factors that had led to the presence of active caries. The program included counseling sessions with emphasis on enhancing use of the children's own resources in everyday life. Toothbrushes, fluoride toothpaste and fluoride and xylitol lozenges were distributed to the children. They also received applications of fluoride/chlorhexidine varnish. The children in the control group (n = 247) received basic prevention offered as standard in the public dental clinics in Pori. For both groups, the average follow-up period was 3.4 years. A community level program of oral health promotion was run in Pori throughout this period. Mean DMFS increments for the experimental and control groups were 2.56 (95% CI 2.07, 3.05) and 4.60 (3.99, 5.21), respectively (p < 0.0001): prevented fraction 44.3% (30.2%, 56.4%). The results show that by using a regimen that includes multiple measures for preventing dental decay, caries increment can be significantly reduced among caries-active children living in an area where the overall level of caries experience is low.     

Socio-economic effect on caries. Incidence data among Swedish 12-14-year-olds

OBJECTIVE: To assess whether socioeconomic factors are associated with the progression of caries, independently of a previous history of caries. SUBJECTS AND METHODS: In 1995, as part of a longitudinal study of preventive measures, 3373 Swedish 12-year-olds were examined for caries and answered a questionnaire regarding socioeconomic level (SEL), ethnicity and residential area. The examination was repeated in 1997 when 3109 of the teenagers participated. Baseline caries and increments in the incidence of caries were computed. The influence of structural variables on baseline caries as well as a 2-year increment were analysed by means of Poisson regression. RESULTS: The risk of having caries as 12-year-olds was greater in workers' and immigrants' children, as well as in urban teenagers. The risk of developing new caries was most influenced by an earlier experience of caries. The social gradient was, however, still visible when a previous experience of caries was accounted for. The pattern found in the cross-sectional data from 1995, with more caries in children from workers' families, therefore prevailed in the increment data. CONCLUSION: Irrespective of earlier caries status there is a social gradient in caries progression. It therefore seems that the preventive methods do not function to the equal benefit of all children.     

The Efficiency of Semiannual Silane Fluoride Varnish Applications: a Two-year Clinical Study in Preschool Children

Objective : The aim of this two-year community demonstration trial was to study the caries inhibitory effects of semiannual applications of a fluoride varnish in preschool children. Methods : Twenty-four public dental health clinics in the county of Halland, Sweden, with 5,137 preschool children, 4 and 5 years of age, were matched and equally allocated to a fluoride varnish group ( n =2,535) and a reference group ( n =2,602). The children in the fluoride varnish group were treated every six months with topical applications of a silane fluoride varnish, Fluor Protector (0.1% F), while no fluoride varnish was used in the reference group. Both groups received a basic preventive program at annual checkups consisting of dietary counseling and instructions to parents to brush their children's teeth at least once daily with fluoridated dentifrice. Caries data were collected by clinical examinations at baseline and after one and two years. Results : Caries prevalence at baseline did not differ significantly between the groups. After two years, the mean caries incidence was low and no statistical difference was found in the total number of carious and filled surfaces (dfs) between the two groups. However, the incidence of approximal lesions (dfsa) was significantly lower ( P <.05) in the fluoride varnish group than the reference group. Children in the fluoride varnish group with dfs scores of 1–4 and ≥5 at the start of the study exhibited a statistically significant ( P <.05) reduction in approximal caries incidence of 19 percent and 25 percent, respectively, when compared with the reference group. Conclusion : Preschool children 4 and 5 years of age with clinical caries who receive semiannual applications of a silane fluoride varnish containing 0.1 percent F experience a reduced incidence of approximal caries over two years.