Carbamide-containing polyol chewing gum and prevention of dental caries in schoolchildren in Madagascar

Oral health promotion through health-promoting schools in developing countries: A scoping review

OBJECTIVES

To explore and assess what is known about oral health promotion through health-promoting primary schools in developing countries.

METHODS

A scoping review was conducted using the Arksey & O'Malley framework. Web of Science, PubMed, Scopus and Cochrane Library were searched, followed by the reference lists of the resulting studies. The UN classification of developing countries was used to define the countries included and the search was between 1986 and 2021. Quality assessment was carried out using Joanna Briggs Institute's quality appraisal tools.

RESULTS

The search resulted in 33 studies of which almost half were randomized controlled trials. The oral health promotion strategies were oral health education (n = 16) delivered by teachers, parents or peers, or multicomponent involving both toothbrushing (n = 15) and dietary components (n = 2). Most of the included studies were conducted in Asia (n = 25/33).

CONCLUSIONS

Findings suggested that comprehensive, multicomponent theory-based oral health promotion showed improvements in oral health outcomes of schoolchildren, particularly if delivered using a whole-school approach. However, further research on feasibility and implementation of oral health promotion through health-promoting primary schools in developing countries should be considered.

Oral microbiota in human health and disease: A perspective

The evolution of medical knowledge about oral microbiota has increased awareness of its important role for the entire human body health. A wide range of microbial species colonizing the oral cavity interact both with each other and with their host through complex pathways. Usually, these interactions lead to a harmonious coexistence (i.e. eubiosis). However, several factors - including diet, poor oral hygiene, tobacco smoking, and certain medications, among others - can disrupt this weak homeostatic balance (i.e. dysbiosis) with potential implications on both oral (i.e. development of caries and periodontal disease) and systemic health. This article is thus aimed at providing an overview on the importance of oral microbiota in mediating several physiological and pathological conditions affecting human health. In this context, strategies based on oral hygiene and diet as well as the role of probiotics supplementation are discussed.

The Effect of Structured Education Training Program on Oral Health Awareness Among School-Going Children of Central India: A Cross-Sectional Study

Background

In order to curb the ever-increasing load of diseases related to the oral cavity, there is a call for generating organized school-based oral health education and training programs. It is proposed that there will be an emphasis on the primary care of oral health of school-going children proven, which is often neglected. This will be beneficial for the early detection, intervention and thus prevention of further debilitating conditions of the pathologies pertaining to the oral cavity with the assistance of the structured program suggested in this article.

Aim

The aim of the study was the evaluation of oral health programs for oral health awareness and knowledge among school-going children in the Central India region.

Settings and design

This is a cross-sectional study with measurements before and after the implementation of the oral care program. 

Materials and methods

This cross-sectional study, approved by the Institutional Ethical Committee, Datta Meghe Institute of Medical Sciences, Wardha, has been done according to the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) checklist. A study based on certain questions was carried out amongst the school-going children of Central India, especially the Vidarbha region. A total of 250 school-going children were enrolled in the study. A survey based on a questionnaire was carried out among the study participants in the age group of 12-16 years of age, which consisted of questions pertaining to knowledge of oral health and hygiene maintenance. The program consisted of presentation slides, role-plays, and demonstrations for inculcating the knowledge.

Result

A total of 200 study participants responded to the questionnaire. Overall, the baseline mean score of knowledge with scale was 2.80 ± 1.73 SD, which after the intervention was observed to be 10.70 ± 0.54 SD, which showed an increase. There was an aptly 60.4% increase in test scores related to oral health after the specific oral health inculcation program based on questionnaire execution which was statistically significant (p<0.001).

Conclusion

A properly constructed school children-based oral health education and training program induces better results in the oral health-related comprehension of students.

[Pilot Project for Occupational Dental Prevention]

AIM OF THE STUDY

To investigate the feasibility and effectiveness of a low-threshold disease prevention offer in a pilot project for employees Methodology: Employees of a company working in office or on production (n=144; 90 women, 54 men) with an average age of 39.25 (StA 11.5) years were interviewed and clinically examined using a questionnaire on habits and knowledge in the prevention of dental diseases. The oral hygiene indices Papillae Bleeding Index (PBI) and the modified Approximal Plaque Index (mAPI) as well as exploratory depth measurements (STM) were collected. Subsequently, a training in dental disease prevention was carried out with a specially produced video as well as the provision of sugar-free chewing gum and mouthwash solutions for twice daily use for a period of one year. After one year, the questionnaire was again issued and the clinical parameters were collected. The study was approved by the UW/H Ethics Committee. Statistical analysis was carried out with SPSS 26.

RESULTS

85 patients with an average age of 39.23 (StD 11.3) years could be examined after one year (59 women, 26 men). The analysis of the questionnaire showed a significant improvement in oral health behavior. The corresponding total score improved from 10.68 (1.93) to 9.97 (1.60) (p<0.05). The PBI improved from 0.43 (0.40) to 0.31 (0.36) (p<0.05), the mAPI from 1.54 (0.51) to 1.35 (0.39) (p<0.01). The STM was reduced from 1.83 (0.39) to 1.56 (0.36) (p<0.001).

CONCLUSION

The dental disease prevention program for employees appears suitable for implementation at workplace and has shown significant improvements in oral health behavior as well as in clinical parameters.

Synbiotics in caries prevention: A scoping review

The scoping review aimed to examine the evidence on the role of synbiotics in caries prevention. PubMed, SCOPUS, and Web of Science databases search were performed. Any in vitro study, clinical trial, systematic review with/without meta-analysis, umbrella review/meta-evaluation, narrative review addressing the role of synbiotics in caries prevention were included in the scoping review. Data were extracted from the included studies using pre-approved registered protocol. Twenty-eight records were identified, of which 5 in vitro studies, 1 quasi-experimental clinical trial and 1 narrative review were included in the present review. No controlled clinical trials or systematic reviews on the role of synbiotics in caries prevention could be identified. Except 1, all in vitro studies examined the combined effect of saccharides and lactobacilli spp. as potential synbiotics on the growth of Streptococcus mutans. However, the proposed synbiotics in 4 in vitro studies either did not qualify or remained ambiguous of its eligibility as a potential synbiotic for caries prevention. One recent in vitro study explored the possibility of L-arginine and Lactobacillus rhamnosus GG synbiotic for caries prevention. The quasi-experimental clinical study without a control arm did not explicitly mention the intervention composition and thus, its synbiotic potential remains unclear. A narrative review highlighted the potential of combining arginine (prebiotic) with arginolytic bacteria (probiotic) as a synbiotic, which appears promising for caries prevention. The eligibility of the proposed synbiotics as a true synbiotic needs to be carefully addressed. Due to a lack of controlled clinical studies on synbiotics for caries prevention, evidence on their caries-preventive potential is weak. Future studies are needed to examine the combination of amino acids (esp. arginine) with probiotics as a potential synbiotic against cariogenic pathogens.

Critical Appraisal of Oral Pre- and Probiotics for Caries Prevention and Care

In recent years, the concept of preventing caries-related microbial dysbiosis by enhancing the growth and survival of health-associated oral microbiota has emerged. In this article, the current evidence for the role of oral pre- and probiotics in caries prevention and caries management is discussed. Prebiotics are defined as "substrates that are selectively utilized by host microorganisms conferring a health benefit." With regard to caries, this would include alkali-generating substances such as urea and arginine, which are metabolized by some oral bacteria, resulting in ammonia production and increase in pH. While there is no evidence that urea added to chewing gums or mouth rinses significantly contributes to caries inhibition, multiple studies have shown that arginine in consumer products can exert an inhibitory effect on the caries process. Probiotics are "live microorganisms which when administrated in adequate amounts confer a health benefit on the host." Clinical trials have suggested that school-based programs with milk supplemented with probiotics and probiotic lozenges can reduce caries development in preschool children and in schoolchildren with high caries risk. Due to issues with research ethics (prebiotics) and risk of bias (prebiotics, probiotics), the confidence in the effect estimate is however limited. Further long-term clinical studies are needed with orally derived probiotic candidates, including the health-economic perspectives. In particular, the development and evaluation of oral synbiotic products, containing both prebiotics and a probiotic, would be of interest in the future management of dental caries.

Elevating the use of sugar-free chewing gum in Germany: cost saving and caries prevention

OBJECTIVE

To analyse the lifetime monetary and health related effects of the consumption of sugar-free chewing gum.

MATERIAL AND METHODS

Using a Markov model we assumed that the German consumption of sugar-free chewing gum (111 gums/year) could be elevated to the level of Finland (202 gums/year). The calculation was based on a model patient representing the development of oral health from the age of 12 to 74 years and clinical data on the effectiveness of chewing sugar-free gum. Lifetime and yearly costs for the 'Finland-scenario' were determined and compared with the actual German expenses of the statutory health insurance companies for dental health.

RESULTS

The actual total lifetime expenditures of the statutory health insurance companies are 17,199.96€ per capita and would be 12,188.94€ in the scenario with elevated consumption of sugar-free chewing gum in Germany. Thus, 5011.02€ per capita could be saved in a lifetime and 80.82€ per year.

CONCLUSIONS

On a national scale, the elevation of the consumption of sugar-free chewing gum in Germany to the level of Finland would lead to a considerable benefit for cost saving and oral health for the statutory health insurance companies.

Effect of a school-based oral health education in preventing untreated dental caries and increasing knowledge, attitude, and practices among adolescents in Bangladesh

Background

There is a dearth of published literature that demonstrates the impact and effectiveness of school-based oral health education (OHE) program in Bangladesh and it is one of the most neglected activities in the field of public health. Keeping this in mind, the objectives of this study were to assess the effectiveness of OHE program in: 1) increasing oral health knowledge, attitude, and practices and 2) decreasing the prevalence of untreated dental caries among 6–8 grade school students in Bangladesh.

Methods

This intervention study was conducted in Araihazar Thana, Narayanganj district, Bangladesh during April 2012 to March 2013. The total participants were 944 students from three local schools. At baseline, students were assessed for oral health knowledge, attitude and practices using a self-administered structured questionnaire and untreated dental caries was assessed using clinical examination. Follow up study was done after 6 months from baseline. McNemar’s chi-square analysis was used to evaluate the impact of OHE program on four recurrent themes of oral health between the baseline and follow-up. Multiple logistic regression analyses were used to determine the impact of the intervention group on our outcome variables.

Results

Significant improvement was observed regarding school aged adolescents’ self-reported higher knowledge, attitude and practices scores (p < 0.001) at follow-up compared with baseline. The prevalence of untreated dental caries of the study population after the OHE program was significantly (p < 0.01) reduced to 42.5 %. Multiple logistic regression analyses showed that the OHE intervention remained a significant predictor in reducing the risk of untreated dental caries (adjusted odds ratio [AOR] =0.51; 95 % confidence interval [CI] = 0.37, 0.81). In the follow-up period participants were 2.21 times (95 % CI = 1.87, 3.45) more likely to have higher level of knowledge regarding oral health compared to baseline. Compared with baseline participants in the follow-up were 1.89 times (95 % CI = 1.44–2.87) more likely to have higher attitude towards oral health. In addition, OHE intervention was found to be significantly associated with higher level of practices toward oral health (AOR = 1.64; 95 % CI = 1.12, 3.38).

Conclusions

This study indicated that OHE intervention was effective in increasing i) knowledge, ii) attitude, and iii) practices towards oral health; it also significantly reduced the prevalence of untreated dental caries among school aged adolescents from grade 6–8 in a deprived rural area of Bangladesh.

Sugar-free chewing gum and dental caries: a systematic review

Objective:

To appraise existing evidence for a therapeutic / anti-cariogenic effect of sugar-free chewing gum for patients.

Method:

9 English and 2 Portuguese databases were searched using English and Portuguese keywords. Relevant articles in English, German, Portuguese and Spanish were included for review. Trials were excluded on lack of randomisation, control group, blinding and baseline data, drop out rate >33%, no statistical adjustment of baseline differences and no assessment of clinically important outcomes. Reviews were excluded on lack of information, article selection criteria, search strategy followed, search keywords, searched databases or lack of study-by-study critique tables. In cases of multiple reports from the same study, the report covering the longest period was included. Two reviewers independently reviewed and assessed the quality of accepted articles.

Results:

Thirty-nine articles were included for review. Thirty were excluded and 9 accepted. Of the 9 accepted, 2 trials of reasonable and good evidence value did not demonstrate any anti-cariogenic effect of sugar-free chewing gum. However, 7 articles, with 1 of strong, and 6 of good evidence value, demonstrated anti-cariogenic effects of chewing Sorbitol, Xylitol or Sorbitol/Xylitol gum. This effect can be ascribed to saliva stimulation through the chewing process, particularly when gum is used immediately after meals; the lack of sucrose and the inability of bacteria to metabolize polyols into acids.

Conclusion:

The evidence suggests that sugar-free chewing gum has a caries-reducing effect. Further well-designed randomised trials are needed to confirm these findings.

The impact of polyol-containing chewing gums on dental caries: a systematic review of original randomized controlled trials and observational studies

BACKGROUND

The authors conducted a systematic review of original studies that was designed to assess the impact of polyol-containing chewing gum on dental caries compared with the effect with no chewing gum.

REVIEW METHODS

The authors searched MEDLINE, The Cochrane Library and Google Scholar up to May 2008 to identify peer-reviewed articles that compared polyol-containing chewing gum with no chewing gum. The authors extracted study characteristics, data on incremental dental caries and quality by consensus. Data on prevented fraction (PF) were pooled across studies.

RESULTS

The results of 19 articles with data from 14 study populations showed that the use of xylitol, xylitol-sorbitol blend and sorbitol were associated with mean PF (95 percent confidence interval) of 58.66 percent (35.42-81.90), 52.82 percent (39.64-66.00) and 20.01 percent (12.74-27.27), respectively. For the sorbitol-mannitol blend, it was 10.71 percent (-20.50-41.93), which was not statistically significant. Sensitivity analyses confirmed the robustness of the findings.

CLINICAL IMPLICATIONS

Although research gaps exist, particularly on optimal dosing and relative polyol efficacy, research evidence supports using polyol-containing chewing gum as part of normal oral hygiene to prevent dental caries.

Remineralization of enamel subsurface lesions in situ by the use of three commercially available sugar-free gums

BACKGROUND

Commercially available sugar-free chewing gums have been claimed to provide oral health benefits.

AIM

The aim of this randomized, double-blind crossover in situ study was to compare the efficacy of three commercially available sugar-free chewing gums: Trident White, Orbit, and Orbit Professional, in remineralizing enamel subsurface lesions in situ.

DESIGN

Specimens containing enamel subsurface lesions were sectioned into test and control half-slabs with the test half-slabs inserted into removable palatal appliances. For each test chewing period, subjects were randomly allocated one of three test gums. Subjects (n = 10) chewed the randomly allocated gum for a 20-min period four times per day for 14 days. Each subject chewed all three test gums, with a 7-day washout period between crossovers. After each 14-day cycle, test and control half-slabs were paired, embedded in resin, sectioned, and subjected to microradiography to determine remineralization.

RESULTS

The gum TW produced significantly greater remineralization (18.4 +/- 0.9%) than Orbit (8.9 +/- 0.5%) and Orbit Professional (10.5 +/- 0.9%).

CONCLUSION

The superior remineralization activity of the TW gum in situ was attributed to the presence of casein phosphopeptide-amorphous calcium phosphate nanocomplexes.

Dental plaque formation and salivary mutans streptococci in schoolchildren after use of xylitol-containing chewing gum

OBJECTIVE

The aim of this study was to investigate the effect of a fixed daily dose of xylitol on mutans streptococci in saliva and the amount of visible dental plaque. A second aim was to explore if the possible effects differed between children with and without caries experience.

METHODS

The study was designed as a double-blind randomized controlled trial with two parallel arms. All pupils (n=149) in grades 1-6 in a comprehensive school in northern Sweden were invited, and 128 children (mean age=12.7 years) consented to participate. The children were stratified as having caries experience (DMFS/dmfs>or=1) or not before the random allocation to a test or control group. The control group (A) was given two pellets containing sorbitol and maltitol three times daily for 4 weeks, and the test group (B) received corresponding pellets with xylitol as single sweetener (total dose=6.18 g day). Clinical scoring and saliva samples were collected at baseline and immediately after the test period. The outcome measures were visible plaque index, salivary mutans streptococci counts and salivary lactic acid production.

RESULTS

The amount of visible plaque was significantly reduced in both groups after 4 weeks (P<0.05). Likewise, the sucrose-induced lactic acid formation in saliva diminished in both groups (P<0.05). The proportion of mutans streptococci decreased significantly in the test group compared to baseline, but not in the control group (P<0.05). The alterations in the test group seemed most prominent among children without previous caries experience.

CONCLUSIONS

The results suggest that chewing gum with xylitol or sorbitol/maltitol can reduce the amount of dental plaque and acid production in saliva in schoolchildren, but only the xylitol-containing gum may also interfere with the microbial composition.

Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664]

Background

Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks.

Methods

Participants (n = 132) were randomized to either active groups (10.32 g xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration.

Results

There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant.

Conclusion

There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically significant.

The use of sorbitol- and xylitol-sweetened chewing gum in caries control

BACKGROUND

The author compared the caries-inhibitory action of sorbitol- and xylitol-sweetened chewing gum and assessed the role of these products in caries prevention.

TYPES OF STUDIES REVIEWED

The author reviewed studies including randomized field trials with substantial numbers of participants and observational studies. He did not review case studies. He found studies through a MEDLINE search and by hand searching.

RESULTS

When compared with sugar-sweetened gum, sorbitol-sweetened gum had low cariogenicity [corrected] when it was chewed no more than three times per day. Xylitol-sweetened gum was noncariogenic in all of the protocols tested. Some studies claimed that xylitol-sweetened gum had an anticariogenic effect, though these claims need further study. There also is good evidence that when mothers of infants and young children chew xylitol-sweetened gum, it will block transmission of mutans streptococci from mother to child.

CLINICAL IMPLICATIONS

The evidence is strong enough to support the regular use of xylitol-sweetened gum as a way to prevent caries, and it can be promoted as a public-health preventive measure. Chewing xylitol-sweetened gum, especially for patients who like chewing gum, can be fitted readily into a regimen that includes frequent fluoride exposure, good oral hygiene and regular dental appointments.

Effect of xylitol on mutans streptococci and lactic acid formation in saliva and plaque from adolescents and young adults with fixed orthodontic appliances

This study aimed to investigate two dose regimens of xylitol-containing tablets on the ecology of dental plaque and saliva during treatment with fixed orthodontic appliances. The study group comprised 56 healthy patients (mean age 15.8 yr) randomly assigned into the following groups: A, (n = 23) two xylitol tablets two times a day (1.7 g xylitol d(-1)) for 18 wk; B, (n = 23) two tablets four times per day (3.4 g xylitol d(-1)) for 18 wk; and C, (n = 10) no tablets. The levels of mutans streptococci (ms) were enumerated in plaque and saliva and the proportion of xylitol-sensitive (X(S)) strains in saliva was determined by autoradiography with [(14)C]-xylitol at baseline and at 6, 12, and 18 wk. The lactic acid formation rate was assessed enzymatically in sucrose-challenged plaque suspensions. A drop in salivary ms levels was found in Group A after 6 wk but not after 12 or 18 wk. The proportion of X(S) ms was decreased after 6 wk in groups A and B and remained so during the experimental period. The lactic acid formation rates decreased slightly ( approximately 10%) in the two xylitol groups compared with baseline. In conclusion, our results showed that although an alteration of ms strains was demonstrated following a regular daily low-dose intake of xylitol, the long-term total ms counts in plaque and saliva as well as plaque acidogenicity remained unchanged.

Effect of a school-based oral health education programme in Wuhan City, Peoples Republic of China

OBJECTIVES

To assess oral health outcomes of a school-based oral health education (OHE) programme on children, mothers and schoolteachers in China, and to evaluate the methods applied and materials used.

DESIGN

The WHO Health Promoting Schools Project applied to primary schoolchildren in 3 experimental and 3 control schools in Hongshan District, Wuhan City, Central China, with a 3-year follow-up. Data on dental caries, gingival bleeding and behaviour were collected.

PARTICIPANTS

803 children and their mothers, and 369 teachers were included at baseline in 1998. After three years, 666 children and their mothers (response rate 83%), and 347 teachers (response rate 94%) remained.

RESULTS

DMFT/DMFS increments were comparable but the f/F components were higher among children in experimental schools than in control schools and the gingival bleeding score was, similarly, significantly lower. More children in experimental schools adopted regular oral health behaviour such as toothbrushing, recent dental visits, use of fluoride toothpaste, with less frequent consumption of cakes/biscuits compared to controls. In experimental schools, mothers showed significant beneficial oral health developments, while teachers showed higher oral health knowledge and more positive attitudes, also being satisfied with training workshops, methods applied, materials used and involvement with children in OHE.

CONCLUSIONS

The programme had positive effects on gingival bleeding score and oral health behaviour of children, and on oral health knowledge and attitudes of mothers and teachers. No positive effect on dental caries incidence rate was demonstrated by the OHE programme.

Dietary factors in the prevention of dental caries: a systematic review

The aim of this study was, systematically, to evaluate the effect of dietary changes in the prevention of dental caries. A search and analysis strategy was followed, as suggested by the Swedish Council on Technology Assessment in Health Care (SBU). The search strategy for articles published in 1966-2003 was performed using electronic databases and reference lists of articles and selected textbooks. Out of 714 articles originally identified, 18 met the inclusion criteria for a randomized or controlled clinical trial--at least 2 years' follow-up and caries increment as a primary endpoint. This included the total or partial substitution of sucrose with sugar substitutes or the addition of protective foods to chewing gum. No study was found evaluating the effect of information designed to reduce sugar intake/frequency as a single preventive measure. It is suggested that the evidence for the use of sorbitol or xylitol in chewing gum, or for the use of invert sugar, is inconclusive. No caries-preventive effect was found from adding calcium phosphate or dicalcium phosphate dihydrate to chewing gums. The review dearly demonstrates the need for well-designed randomized clinical studies with adequate control groups and high compliance.

The efficacy of two prototype chewing gums for the removal of extrinsic tooth stain

AIM

To compare the potential efficacy of two prototype chewing gums in extrinsic stain removal on natural teeth.

SETTING

Dental school clinics.

DESIGN

Double-blind, two groups, parallel design.

PARTICIPANTS

76 adult volunteers (32m, 44f, mean age: 20.6 years old).

METHODS

Oral hard and soft tissue health was examined. The subjects were randomly assigned to use either Product A (without active ingredients) or Product B (with active ingredients). Each subject was asked to brush their teeth for one minute twice daily (mornings and nights) and chew the gums supplied for 15 min (2 dragees each time), three times daily, once after each meal (breakfast, lunch and dinner) for the entire four-week duration. Dental stain assessment was made on the 12 incisors using the Lobene Stain Index (LSI).

RESULTS

The overall difference between the stain scores after 4-weeks' use of the chewing gums was statistically significant (p<0.01) for both test Product A (10.84) and Product B (7.77) with regard to the mean baseline stain scores (21.57). This difference represented a 48% reduction in stain scores for those subjects using Product A, while the reduction was 64% for the subjects using Product B.

CONCLUSIONS

The results of this in vivo study suggest that chewing gums with and without active ingredients have potential effect on stain removal after regular use for one month.

Determinants of Dropout in a Community Intervention Trial on the Caries-preventive Effect of Chewing Gums

OBJECTIVES

This study describes determinants of dropout in a three-year community intervention trial of the effects of sugar-substituted chewing gums on caries progression rates.

METHODS

A total of 602 children aged 9-14 years from 28 school classes in five secondary schools in Kaunas, Lithuania, were given a clinical and radiographic baseline caries examination. The schools were assigned randomly to one of the following interventions: sorbitol/carbamide gum, sorbitol gum, xylitol gum, placebo gum, or no gum. Children in the four intervention schools were asked to chew at least five pieces of chewing gum per day, preferably after meals. The children were reexamined clinically after one, two, and three years of study, and radiographically after three years.

RESULTS

A total of 33 children (6%) had dropped out before the one-year clinical examination, an additional 29 children (5%) dropped out before the two-year examination, and a further 108 children (18%) dropped out before the final three-year clinical examination. A total of 230 children (39%) were not available or refused to participate in the three-year radiographic examination. Analyses using random effect logit models showed that, irrespective of time of follow-up, most of the cluster variation in dropout was related to school classes within the primary randomization units, the schools. The most important predictors of individual dropout were age and baseline caries experience, whereas sex was not associated with dropout.

CONCLUSIONS

The results show that a community intervention trial of chewing gums carried out among schoolchildren is subject to cluster effects. Dropout was not primarily related to the randomization units themselves, i.e. the schools, but rather to subclusters of classes within the schools. These findings should be considered when designing community intervention trials and practical preventive programs among schoolchildren.