Free sugars and early childhood caries development: a prospective cohort study

PURPOSE

To investigate the impact of giving children younger than 2 years foods and beverages with free sugars on the prevalence of early childhood caries at 5 years.

MATERIALS AND METHODS

The study group consisted of 208 children (105 boys and 103 girls) with a complete set of data on nursing, diet and caries from birth to 5 years. We collected feeding habits and dietary data through structured questionnaires at 6, 12, 18 and 24 months and the presence of decayed (d), missed (m) and filled (f) teeth was scored according to the WHO criteria at five years of age. We processed data with chi-square tests and expressed as relative risk (RR) with 95% confidence intervals.

RESULTS

At the age of 5 years, 22% of the children had caries. Intake of fruit juice with meals (RR 2.3) and cookies or biscuits at 24 months of age (RR 2.4), as well as fast food consumption at least once every week (RR 2.9), more than doubled the risk for early childhood caries (p < 0.05).

CONCLUSIONS

Within the limitations of the present study, we found a relationship between consumption of free sugars early in life and dental caries prevalence at 5 years. It therefore seems important to embrace and emphasise the current sugar recommendations in primary and dental care to educate caregivers to avoid serving free sugars to their children before the age of 2 years.

Prevention of Recurrent Childhood Caries with Probiotic Supplements: A Randomized Controlled Trial with a 12-Month Follow-Up

The aim of this study was to evaluate the effect of drops containing probiotic bacteria on the recurrence of dental caries in preschool children. The study employed a randomized, placebo-controlled, double-blinded design with two parallel arms. 38 preschool children were enrolled after comprehensive restorative treatment under general anesthesia or conscious sedation (baseline), and they were followed up after 6 and 12 months. Parents of children in the test group were instructed to give 5 daily drops containing two strains of Limosilactobacillus reuteri (DSM 17938 and ATCC PTA 5289) at bedtime. The placebo drops were identically composed but lacked bacteria. The duration of the intervention was 12 months. The primary endpoint was recurrence of new caries lesions on subject level (yes/no), and secondary endpoints were presence of dental plaque and gingivitis. We found high rate of recurrent moderate and extensive lesions after 12 months (67%) but there were no significant differences between the groups. We observed no beneficial effects on dental plaque or gingival inflammation. The findings were however uncertain and inconclusive due to lack of power, a consequence of the COVID-19 pandemic. ClinTrials.gov Identifier: (NCT04929340), June 18, 2021; retrospectively registered.

Can probiotic supplements prevent early childhood caries? A systematic review and meta-analysis

The aim of this study was to explore the preventive effect of probiotic supplements on the development of early childhood caries (ECC). We searched the PubMed, Google Scholar and Cochrane databases up to January 15, 2021. The authors screened the hits independently for relevance, extracted outcome data and assessed the risk of bias. We performed a random effects meta-analysis to pool and compare the incidence of ECC in children assigned to test or placebo groups, respectively. The authors included nine randomised controlled trials published between 2001 and 2021, involving 2,363 preschool children. We assessed two publications with a moderate risk of bias and seven with high risk of bias. The median caries incidence in the probiotic test groups was 8.5% compared with 17.5% in the placebo groups and this difference was statistically significant (P<0.001). A pooled random effects meta-analysis on caries incidence on subject level showed a small but statistically significant risk difference in favour of the probiotic intervention (-0.05, 95% confidence interval (CI) -0.10, -0.00; P<0.05). The mean difference in caries increment on tooth/surface level was -0.57, (95% CI -0.91, -0.23; P<0.01). In conclusion, we demonstrated a small but statistically significant preventive effect of probiotic supplements on ECC. However, the certainty of this finding was low due to the risk of bias, heterogeneity and inconsistencies across the studies. Further long-term randomised controlled trials with low risk of bias are required in order to answer the research question with a higher certainty.

Effects of Lactobacillus reuteri-containing lozenges on healing after surgical removal of mandibular third molars: a randomised controlled trial

We investigated the effect of probiotic supplements on oral wound healing, swelling, pain and discomfort after surgical removal of mandibular third molars. A second aim was to evaluate if the intervention could influence the concentrations of oxytocin in saliva. Sixty-four consecutive volunteers (18-34 years) were enrolled to a double-blind randomised placebo-controlled trial with two parallel arms. Following surgery, the patients were asked to take three lozenges per day containing two strains of Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo for two weeks. The clinical healing and extra-oral swelling were scored two weeks post-operatively. Samples of wound exudate were cultivated for the presence of Staphylococcus aureus and β-haemolytic streptococci. Salivary oxytocin concentrations were analysed from pre- and post-surgery samples using ELISA technique. Compliance and the subjective perception of swelling, pain and discomfort were reported daily through visual analogue scales in a logbook. All patients except three completed the protocol and the postoperative course was uneventful in most cases. Minor extra-oral swellings were noted in five patients, but none required antibiotic treatment. At the 2-week follow-up, there were no significant differences in clinical wound healing index, extra-oral swelling, bacterial growth or salivary oxytocin levels between the groups. The self-reported data unveiled, however, a significantly reduced sense of swelling, in particular during the second week after surgery in the probiotic test group (P<0.05). Likewise, significantly fewer nights with disturbed sleep and fewer days with sick-leave from work were reported among the participants in the test group (P<0.05). No differences were found in the post-operative use of analgesics. In conclusion, we found no significant influence of probiotic supplements on objective wound healing after surgical extraction of impacted mandibular third molars. However, since the patients' perceived significant post-operative ameliorations, further studies are needed to explore the patient's value of the intervention.

Effect of probiotic lozenges containing Lactobacillus reuteri on oral wound healing: a pilot study

It has been suggested that beneficial bacteria may stimulate wound healing. The aim was to investigate the effect of topical applications of probiotic lactobacilli on the healing of standardised oral wounds. This pilot study employed a randomised, placebo-controlled, double-blind cross-over design. Standardised biopsies were punched in the oral mucosa of 10 healthy volunteers, with and without exposure to two strains of Lactobacilli reuteri administrated as lozenges and topical oil. The healing was scored clinically after 2, 5 and 8 days. The amount of exudate was quantified through filter papers and the levels of selected cytokines and chemokines were determined with multiplex immunoassays. Saliva samples were collected before the biopsy and after healing for determination of oxytocin with ELISA. Subjectively perceived pain and discomfort was reported through a daily logbook. There was a clear tendency of improved healing in test group at the 2-and 5-day check-ups but the difference compared with the placebo intervention was not statistically significant (P=0.08). Higher but non-significant expressions of the tumour necrosis factor (TNF) superfamily ligand members 13 (APRIL) and 13B (BAFF), as well as the chemokine interleukin 8 (IL-8), were displayed in wound exudates from the probiotic group as compared with placebo, particularly after 5 and 8 days. The salivary levels of oxytocin were significantly lower (P<0.05) in the placebo group at the 8-day follow-up. The mean number of days with pain and/or discomfort after the biopsies was similar in both groups. No side-effects were reported. The findings of this pilot study justify a larger clinical trial to elucidate the possible role of probiotic supplements on oral wound healing.

Effect of tablets containing probiotic candidate strains on gingival inflammation and composition of the salivary microbiome: a randomised controlled trial

The aim of the study was to investigate clinical and microbial effects of probiotic candidate strains in patients with moderate gingivitis. The null hypothesis was that the clinical measurements with treatment would not differ from placebo. 47 adult patients were enrolled in a randomised placebo-controlled trial with a 4-week intervention of tablets containing a mix of Lactobacillus rhamnosus PB01, DSM 14869 and Lactobacillus curvatus EB10, DSM 32307 or placebo. Clinical examinations and samplings were done at baseline and after 2, 4 and 6 weeks. The clinical endpoints were general bleeding on probing (BOP), general plaque index (PI) and flow of gingival crevicular fluid (GCF). In addition, the concentration of selected cytokines (interleukin (IL)-1β, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-α)) in GCF was determined with multiplex immunoassays. The profiles of the salivary microbiome were analysed with Next Generation Sequencing (NGS) and qPCR. In contrast to the placebo group, there was a significant reduction in BOP and amount of GCF (P<0.05) after 4 weeks in the probiotic test group when compared with baseline. The general PI was less affected although there was a tendency of decreased plaque levels in the probiotic group (P=0.05-0.09). The cytokines were unaffected by the intervention as well as the salivary microbiome. The Shannon index showed no significant differences between the groups or alterations over time. The occurrence of both probiotic strains increased in saliva of the test subjects during the intervention but returned to baseline levels within 2 weeks. Although a marked improvement in gingival health was recorded in the probiotic group, the null hypothesis could not be rejected.

Impact of Oral Hygiene Discontinuation on Supragingival and Salivary Microbiomes

The purpose of the present study was to characterize and compare supragingival and salivary microbiotas during a 10-d period of oral hygiene discontinuation. We tested the hypothesis that the composition of the salivary microbiota will reflect local microbial changes associated with accumulated biofilm formation and maturation. Pooled supragingival plaque (n = 145) and stimulated saliva (n = 145) samples were collected and plaque and gingival indices were recorded from 29 orally healthy individuals at baseline, during oral hygiene discontinuation (days 4, 7, and 10), and 14 d after resumption of oral hygiene. Supragingival and salivary microbiotas were processed by next-generation sequencing (Human Oral Microbe Identification using Next Generation Sequencing) and microbial community profiles were compared. Microbial composition of supragingival plaque samples collected after 4, 7, and 10 d of oral hygiene discontinuation, as well as 14 d after reuptake of oral hygiene, differed significantly from baseline samples, by a 3-fold increase in relative abundance Leptotrichia species and a 2-fold decrease in Streptococcus species (adjusted P < 0.01). In saliva samples, a significant increase in relative abundance of Leptotrichia species (adjusted P < 0.01) was evident at day 7 but completely reversed 14 d after resumption of oral hygiene. While the salivary microbiota was resistant to accumulated local biofilm formation, data from this study showed that compositional changes of supragingival microbiotas were not reversed 14 d after resumption of oral hygiene, despite the restoration of plaque to baseline levels. (ClinicalTrials.gov UCPH_OI_002, NCT02913235).

Knowledge Transfer Statement: Data from this study showed compositional changes of supragingival microbiotas as a consequence of a 10-d period of oral hygiene discontinuation, that was not reversed 14 d after resumption of oral hygiene. Notably, oral hygiene discontinuation was associated with a significant increase in relative abundance of potential cariogenic Leptotrichia species and a decrease in Streptococcus species. Thus, findings from this study highlight the necessity of regular oral hygiene in the maintenance of oral homeostasis.

Urinary fluoride excretion in preschool children after intake of fluoridated milk and use of fluoride-containing toothpaste

Objective

To assess the urinary fluoride excretion in preschool children after drinking fluoridated milk with 0.185 mg F and 0.375 mg F and to study the impact of use of fluoride toothpaste.

Basic research design

Double-blind cross-over study.

Participants

Nine healthy children, 2.5-4.5 years of age.

Intervention

In a randomized order, participants drank 1.5 dl milk once daily for 7 days with no fluoride added (control), 0.185 mg fluoride added and 0.375 mg fluoride added. The experiment was performed twice with (Part I) and without (Part II) parental tooth brushing with 1,000 ppm fluoride toothpaste. The fluoride content in the piped drinking water was 0.5 mg F/L.

Main outcome measure

Urinary fluoride excretion.

Results

The 24-hour urinary fl uoride excretion/kg body weight varied from 0.014 mg F for the placebo intervention and non-fluoride toothpaste to 0.027 mg F for the 0.375 mg intervention with use of 1,000 ppm fluoride toothpaste. The difference compared with the placebo intervention was not statistically significant for any of the interventions when fluoride toothpaste was used (p⟩0.05) while it was statistically significantly different when non-fluoride toothpaste was used (p⟨0.05).

Conclusions

All sources of fluoride must be considered when designing community programs. With 0.5 mg F/L in the drinking water and daily use of fluoride toothpaste, most children had a fluoride intake optimal for dental health. In this setting, additional intake of fluoride milk was within safe limits up to 0.185 mg/day while conclusions about the safety of 0.375 mg/day were uncertain.

Presence of Lactobacillus reuteri in saliva coincide with higher salivary IgA in young adults after intake of probiotic lozenges

The aim of this study was to compare the concentration of salivary immunoglobulin A (IgA) and the selected interleukins (IL)-1β, IL-6, IL-8 and IL-10 in young individuals with presence and non-presence of Lactobacillus reuteri in saliva after a three-week intervention with probiotic lozenges. The study group consisted of 47 healthy individuals aged 18-32 years with no clinical signs of oral inflammation. In a randomised, double-blind, placebo-controlled, cross-over trial participants ingested two lozenges per day containing two strains of the probiotic bacterium L. reuteri or placebo lozenges. The intervention and wash-out periods were three weeks. Stimulated and unstimulated whole saliva was collected at baseline and immediately after termination of the intervention periods. The samples were analysed for total protein, salivary IgA and selected cytokines. In this extended analysis, data were collected by analysing baseline and follow-up saliva samples related to ingestion of the probiotic lozenges for the presence of L. reuteri through DNA-extraction, PCR-amplification and gel-electrophoresis. At baseline, 27% of the individuals displayed presence of L. reuteri and 42% were positive immediately after the three-week probiotic intervention. Individuals with presence of L. reuteri in saliva had significantly higher (P<0.05) concentrations of salivary IgA and %IgA/protein at the termination of the probiotic intake compared with non-presence. No differences in the cytokine levels were observed. In conclusion, detectable levels of L. reuteri in saliva coincided with higher concentrations of salivary IgA and %IgA/protein in stimulated whole saliva after the three-week daily intake of probiotic lozenges. Our findings suggest that monitoring the presence of probiotic candidates in the oral environment is important to interpret and understand their possible immune-modulating role in maintaining oral health.

Fluoride varnish or fluoride mouth rinse? A comparative study of two school-based programs

OBJECTIVE

In many Danish communities, school-based fluoride programs are offered to children with high caries risk in adjunct to tooth brushing. The purpose of this field trial was to compare the caries-preventive effectiveness of two different fluoride programs in 6-12 year olds.

BASIC RESEARCH DESIGN

Clinical controlled trial.

CLINICAL SETTING

The 2-year study was conducted in Public Dental Clinics in a multicultural low-socioeconomic suburban area of Odense, Denmark with an elevated prevalence of caries compared to the city average.

PARTICIPANTS

1,018 children (aged 6-12 years) from 9 different schools were enrolled after informed consent and their class unit was randomly allocated to one of two fluoride programs.

INTERVENTIONS

One group received a semi-annual fluoride varnish applications (FV) and the other group continued with an existing program with fluoride mouth rinses once per week (FMR). All children received oral hygiene instructions and comprehensive dental care at the local Public Dental Clinics throughout the study period.

MAIN OUTCOME MEASURES

Increment of caries lesions in permanent teeth at both cavitated and initial caries levels.

RESULTS

The groups were balanced at baseline. After two years, 961 children (94.4%) were reexamined. The FV group showed a mean DMFS increment of 0.36 compared to 0.41 in the FMR group. The corresponding values for initial caries lesions were 0.83 and 0.91 respectively.

CONCLUSION

There were no statistically significant differences in caries development over two years among children participating in a school-based fluoride varnish or mouth rinse program.

Effect of Probiotic Bacteria on Oral Candida in Frail Elderly

The aim of this study was to investigate the effect of a daily intake of probiotic lactobacilli on the prevalence and counts of oral Candida in frail elderly patients living in nursing homes. The study had a double-blind randomized placebo-controlled design with 2 parallel arms. The study group consisted of 215 older adults (range, 60 to 102 y) who were enrolled after informed consent. After baseline examination and randomization, the subjects were given 1 lozenge containing 2 strains of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo twice daily (morning and evening). The intervention period was 12 wk, and saliva and plaque samples were collected at baseline and follow-up. The primary end point was prevalence of high Candida counts assessed from chairside tests. Secondary end points were levels of dental plaque and gingival inflammation. The groups were balanced at baseline. The attrition rate to follow-up was 19%. There was a statistically significant reduction in the prevalence of high Candida counts in the probiotic group but not in the placebo group, and the difference was statistically significant in both saliva and plaque (P < 0.05). No significant differences between the groups were noted concerning the levels of supragingival plaque or bleeding on probing. Thus, daily use of probiotic lozenges may reduce the prevalence of high oral Candida counts in frail elderly nursing homes residents (ClinicalTrials.gov NCT02391532).

Effect of a chlorhexidine/thymol and a fluoride varnish on caries development in erupting permanent molars: a comparative study

AIM

To compare the caries preventive effect of a chlorhexidine/thymol-containing antibacterial varnish with a fluoride varnish when topically applied during the eruption of permanent molars.

METHODS

The study group consisted of 189 patients, 5-14 years of age, with one 1st or 2nd permanent molar in the process of eruption. After stratification for type of molar and stage of eruption, the patients were randomised to either quarterly topical applications with an antibacterial varnish (Cervitec(®) Plus; CV group) or biannual applications with a fluoride varnish plus biannual treatments with placebo varnish (Fluor Protector; FV group). The duration of the study was 2 years. The primary endpoint was caries incidence (initial and cavitated) in the erupting molars and the secondary outcome was salivary mutans streptococci (MS) counts.

RESULTS

The groups were balanced with respect to socio-economy, oral hygiene, dietary habits and caries experience at baseline. The dropout rate was 11.6 %. The caries incidence was low (< 10 %) in both groups and there was no significant difference between the CV and FV groups with respect to occlusal caries development in the erupting molars (relative risk 1.08, 95 % CI 0.94-1.25). Significantly lower levels of salivary MS were disclosed in the CV group at the end of the study (p < 0.05).

CONCLUSIONS

No difference in occlusal caries development in young permanent molars was displayed after topical applications of either a chlorhexidine/thymol varnish or a fluoride varnish during tooth eruption.

Effect of tablets containing probiotic bacteria (Lactobacillus reuteri) on early caries lesions in adolescents: a pilot study

The objective of the study was to investigate the effect of tablets containing probiotic lactobacilli on early caries lesions in adolescents with quantitative light-induced fluorescence (QLF). 36 healthy adolescents of both sexes (12-17 years of age) were enrolled and randomly allocated to a placebo-controlled trial with two parallel groups. The test group received two tablets daily containing two strains of Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) for a period of three months, while the control group got identical placebo tablets without live bacteria. The primary outcome was QLF-readings (change in fluorescence, ΔF and lesion area, mm2) at baseline and after 3 months, conducted at two buccal sites of each individual, pre-selected with clearly visible clinical signs of enamel demineralisation (white spots). Significantly more premolars were allocated to the placebo group, while the test group had more incisors (P<0.05). There were no statistically significant differences in fluorescence values between the groups, neither at baseline, nor at the follow-up. There was however a significant decrease in fluorescence over time in the test group, but not in the placebo group (P<0.05). No alterations of the lesion area (ΔA) were found in any group. The inter-examiner intra-class correlation coefficient-value for QLF-readings was excellent. No side- or adverse effects were reported during the intervention period. This pilot study found a significant decrease over time in the test group. However, no statistically significant differences in fluorescence values between the groups were found. Hence, the null hypothesis could not be rejected.

Preventive care delivered within Public Dental Service after caries risk assessment of young adults

OBJECTIVES

To study preventive care provided to young adults in relation to their estimated risk category over a 3-year period.

METHODS

The amount and type of preventive treatment during 3 years was extracted from the digital dental records of 982 patients attending eight public dental clinics. The baseline caries risk assessment was carried out by the patient's regular team in four classes according to a predetermined model, and the team was responsible for all treatment decisions. Based on the variables 'oral health information', 'additional fluoride' and 'professional tooth cleaning', a cumulative score was constructed and dichotomized to 'basic prevention' and 'additional prevention'.

RESULTS

More additional preventive care was provided to the patients in the 'low-risk' and 'some risk' categories than to those classified as 'high' or 'very high' risk (OR = 2.0, 95% CI 1.4-3.0; P < 0.05). Professional tooth cleaning and additional fluorides were most frequently employed in the 'low-risk' and 'some risk' categories, respectively. Around 15% of the patients in the high-risk categories did not receive additional preventive measures over the 3-year period. There was an insignificant tendency that patients with additional prevention developed less caries than those that received basic prevention in all risk categories except for the 'very high-risk' group.

CONCLUSION

The caries risk assessment process was not accompanied by a corresponding targeted individual preventive care in a cohort of young adults attending public dental service. Further research is needed how to reach those with the greatest need of primary and secondary prevention.

Caries risk assessment. A systematic review

OBJECTIVE

To assess the ability of multivariate models and single factors to correctly identify future caries development in pre-school children and schoolchildren/adolescents.

STUDY DESIGN

A systematic literature search for relevant papers was conducted with pre-determined inclusion criteria. Abstracts and full-text articles were assessed independently by two reviewers. The quality of studies was graded according to the QUADAS tool. The quality of evidence of models and single predictors was assessed using the GRADE approach.

RESULTS

Ninety original articles fulfilled the inclusion criteria. Seven studies had high quality, 35 moderate and the rest poor quality. The accuracy of multivariate models was higher for pre-school children than for schoolchildren/adolescents. However, the models had seldom been validated in independent populations, making their accuracy uncertain. Of the single predictors, baseline caries experience had moderate/good accuracy in pre-school children and limited accuracy in schoolchildren/adolescents. The period of highest risk for caries incidence in permanent teeth was the first few years after tooth eruption. In general, the quality of evidence was limited.

CONCLUSIONS

Multivariate models and baseline caries prevalence performed better in pre-school children than in schoolchildren/adolescents. Baseline caries prevalence was the most accurate single predictor in all age groups. The heterogeneity of populations, models, outcome criteria, measures and reporting hampered the synthesis of results. There is a great need to standardize study design, outcome measures and reporting of data in studies on caries risk assessment. The accuracy of prediction models should be validated in at least one independent population.

A randomized clinical trial of the anti-caries efficacy of 5,000 compared to 1,450 ppm fluoridated toothpaste on root caries lesions in elderly disabled nursing home residents

Root caries is prevalent in elderly disabled nursing home residents in Denmark. This study aimed to compare the effectiveness of tooth brushing with 5,000 versus 1,450 ppm of fluoridated toothpaste (F-toothpaste) for controlling root caries in nursing home residents. The duration of the study was 8 months. Elderly disabled residents (n = 176) in 6 nursing homes in the Copenhagen area consented to take part in the study. They were randomly assigned to use one of the two toothpastes. Both groups had their teeth brushed twice a day by the nursing staff. A total of 125 residents completed the study. Baseline and follow-up clinical examinations were performed by one calibrated examiner. Texture, contour, location and colour of root caries lesions were used to evaluate lesion activity. No differences (p values >0.16) were noted in the baseline examination with regards to age, mouth dryness, wearing of partial or full dentures in one of the jaws, occurrence of plaque and active (2.61 vs. 2.67; SD, 1.7 vs.1.8) or arrested lesions (0.62 vs. 0.63; SD, 1.7 vs. 1.7) between the 5,000 and the 1,450 ppm fluoride groups, respectively. Mean numbers of active root caries lesions at the follow-up examination were 1.05 (2.76) versus 2.55 (1.91) and mean numbers of arrested caries lesions were 2.13 (1.68) versus 0.61 (1.76) in the 5,000 and the 1,450 ppm fluoride groups, respectively (p < 0.001). To conclude, 5,000 ppm F-toothpaste is significantly more effective for controlling root caries lesion progression and promoting remineralization compared to 1,450 ppm F-toothpaste.

Probiotics for caries prevention and control

Modulation of the microbiota for restoring and maintaining health is a growing issue in medical science. A search for relevant clinical trials on the use of probiotic bacteria as a potential and clinically applicable anti-caries measure was performed. According to predetermined criteria, papers were selected and key data on study design, sample size, intervention, duration, and results were extracted. Two animal and 19 human studies were retrieved. Most studies were short-term and restricted to microbiological endpoints, and only 3 human studies reported a caries endpoint. A high degree of heterogeneity among the included investigations hampered the analysis. Significant reductions of mutans streptococci in saliva or plaque following daily intake of probiotic lactobacilli or bifidobacteria were reported in 12 out of 19 papers, whereas 3 reported an increase of lactobacilli. Three caries trials in preschool children and the elderly demonstrated prevented fractions of between 21% and 75% following regular intakes of milk supplemented with L. rhamnosus. No adverse effects or potential risks were reported. The currently available literature does not exclude the possibility that probiotic bacteria can interfere with the oral biofilm, but any clinical recommendation would be premature. Large-scale clinical studies with orally derived specific anti-caries candidates are still lacking.

Lactobacillus reuteri influences regrowth of mutans streptococci after full-mouth disinfection: a double-blind, randomised controlled trial

This study assessed whether the persistence of Lactobacillus reuteri DSM 17938 and ATCC PTA 5289 in saliva could delay the regrowth of mutans streptococci (MS) after a full-mouth disinfection with chlorhexidine (CHX). A randomised, double-blind, placebo-controlled study with a 6-week intervention period and 3- and 6-month follow-up was performed. 62 healthy subjects with moderate to high counts of MS were randomly assigned to a test group (n = 32) or a placebo group (n = 30). Before onset of the intervention, subjects received two sessions of professional cleaning, flossing, and application of CHX varnish and rinsed their mouth with a CHX solution between the sessions (2 days). Thereafter, the test group used probiotic lozenges (2/day) containing L. reuteri (DSM 17938 and ATCC PTA 5289; 1 × 10(8) CFU of each strain), and the placebo group used identical lozenges lacking the lactobacilli. Saliva samples were collected and cultured onto selective media, and isolates of L. reuteri as well as DNA directly extracted from saliva were tested by polymerase chain reaction (PCR) with specific primers. Presence of salivary MS was analysed with a chair-side test. L. reuteri was frequently detected by culture during the intervention period but in only 3 test group subjects at follow-ups. Regrowth of MS statistically significantly differed depending on the presence or absence of L. reuteri DSM 17938 detected by PCR. We conclude that cultivable L. reuteri strains may only sporadically be confirmed after termination of the intervention, but subjects with PCR-detected L. reuteri demonstrated slower regrowth of MS.

Influence of a low xylitol-dose on mutans streptococci colonisation and caries development in preschool children

AIM

To evaluate the effect of xylitol-containing tablets on mutans streptococci colonisation and caries development in preschool children.

STUDY DESIGN

Randomised single-blind prospective design.

METHODS

The material consisted of 132 healthy 2-year-old children, 71 boys and 61 girls and they were assigned to a xylitol tablet (test) group or a non-intervention control group. The mean age was 2 years + 1 month in both groups. The drop-out rate was 10.6% during the 2-year trial. The test group was given 1-2 xylitol tablets (0.5-1g) per day during 1.5 years. Mutans streptococci (MS) enumeration was performed at baseline and semi-annually in the children and at baseline or shortly after in the mothers with a chair-side technique. Caries prevalence was scored at baseline and the age of 4 years.

RESULTS

No statistically significant differences in MS colonisation were disclosed between the test and control groups at baseline or any of the designated follow-ups. A statistically significant positive relationship was found between the maternal salivary MS levels and the colonisation of the children in the control group at 2.5 years, 3 years and 3.5 years (r=0.39, r=0.35; r=0.30; p<0.01, p<0.01 and p<0.05) but not in the xylitol tablet group (p<0.05). The mean caries prevalence was lower in the test group compared with the control group at 4 years of age (dmfs 0.38 +/-1.05 vs. 0.80 +/-2.60) but the difference was not statistically significant.

CONCLUSION

The findings do not support a low-dose xylitol tablet program for caries prevention in preschool children.

Effect of long-term consumption of milk supplemented with probiotic lactobacilli and fluoride on dental caries and general health in preschool children: a cluster-randomized study

The aim of this study was to evaluate the effect of milk supplemented with probiotic bacteria and fluoride on caries development and general health in preschool children. Children 1-5 years of age (n = 248) attending 14 day care centres with 27 units in northern Sweden entered the study. The centres were randomly assigned to two parallel groups: children in the intervention group were served 150 ml milk supplemented with Lactobacillus rhamnosus LB21 (10(7) CFU/ml) and 2.5 mg fluoride per litre for lunch while the control group received standard milk. The double-blind intervention lasted for 21 months (weekdays) and data were collected through clinical examinations and questionnaires. The primary outcome was caries increment and secondary outcomes were measures of general health. The dropout rate was 25%. The mean baseline caries experience was 0.5 dmfs in the intervention units and 0.6 in the control units and after 21 months 0.9 and 2.2 (p < 0.05). The number of days with sick leave was similar in both groups but the children of the intervention units displayed 60% fewer days with antibiotic therapy (mean 1.9 vs. 4.7 days) and 50% less days with otitis media (0.5 vs. 1.0) (p > 0.05). In children who had participated during the whole 21-month intervention, fewer days with otitis media were reported (0.4 vs. 1.3 days, p < 0.05). No serious side effects were reported. It is concluded that daily consumption of milk containing probiotic bacteria and fluoride reduced caries in preschool children with a prevented fraction of 75%. Additional beneficial health effects were evident.

Caries-Preventive Effectiveness of a Fluoride Varnish: A Randomized Controlled Trial in Adolescents with Fixed Orthodontic Appliances

The aim was to evaluate the efficacy of topical fluoride varnish applications on white spot lesion (WSL) formation in adolescents during treatment with fixed orthodontic appliances. The study design was a double-blinded randomized placebo-controlled trial with two parallel arms. The subjects were 273 consecutive 12- to 15-year-old children referred for maxillary treatment with fixed orthodontic appliances. The patients were randomly assigned to a test or a control group with topical applications of either a fluoride varnish (Fluor Protector) or a placebo varnish every 6th week during the treatment period. The outcome measures at debonding were incidence and progression of WSL on the upper incisors, cuspids and premolars as scored from digital photographs by 2 independent examiners. The attrition rate was 5%. The mean number of varnish applications was 10 (range 4-20) in both groups. The incidence of WSL during the treatment with fixed appliances was 7.4% in the fluoride varnish compared to 25.3% placebo group (p < 0.001). The mean progression score was significantly lower in the fluoride varnish group than in the placebo group, 0.8 +/- 2.0 vs. 2.6 +/- 2.8 (p < 0.001). The absolute risk reduction was 18% and the number needed to treat was calculated to 5.5. The results from the present study strongly suggest that regular topical fluoride varnish applications during treatment with fixed appliances may reduce the development of WSL adjacent to the bracket base. Application of fluoride varnish should be advocated as a routine measure in orthodontic practice.

Effect of chewing gums containing xylitol or probiotic bacteria on salivary mutans streptococci and lactobacilli

The aim was to evaluate the effect of xylitol and probiotic chewing gums on salivary mutans streptococci (MS) and lactobacilli (LB). The material consisted of 80 healthy young adults (21-24 years) who volunteered after informed consent. They were assigned by random into one of four parallel study groups: A, probiotic gum group; B, xylitol gum group; C, probiotic + xylitol gum group; and D, placebo gum group. The gums were taken three times daily after meals, and the intervention period was 3 weeks. The probiotic gums contained two strains of Lactobacilli reuteri (ATCC 55730 at a dose of 1 x 10(8) CFU/gum and ATCC PTA 5289 at a dose of 1 x 10(8) CFU/gum), and each pellet of the xylitol gum contained approximately 1.0 g xylitol as single sweetener. Pretreatment and posttreatment samples of stimulated whole saliva were collected and quantified for MS and LB with chair-side kits. A statistically significant reduction (p < 0.05) of salivary MS was displayed in group A and B after the intervention when compared with baseline. A similar but nonsignificant tendency was seen in group C. No alterations of salivary LB was demonstrated in any group. In conclusion, daily chewing on gums containing probiotic bacteria or xylitol reduced the levels of salivary MS in a significant way. However, a combination of probiotic and xylitol gums did not seem to enhance this effect.

Caries in 4-year-old children after maternal chewing of gums containing combinations of xylitol, sorbitol, chlorhexidine and fluoride

AIM

To evaluate the effect of maternal use of chewing gums containing combinations of xylitol, sorbitol, chlorhexidine and fluoride on caries prevalence in a group of mother's 4-year-old children.

STUDY DESIGN

Randomised controlled trial.

METHODS

After screening 416 women with newborn babies, 173 mothers with high counts of salivary mutans streptococci (MS) were randomly assigned into three experimental chewing gum groups containing A) xylitol (n=61), B) chlorhexidine/xylitol/sorbitol (n=55), and C) sodium fluoride/xylitol/sorbitol (n=57). The intervention started when each child was 6 months old, was terminated one year later. All of the mothers were instructed to chew one piece of the appropriate gum for 5 minutes, three times a day. The outcome measure was the presence of cavitated and non-cavitated (enamel) lesions in the primary dentitions of the children at the age of 4 years.

RESULTS

The drop-out rate in the experimental groups was 15-20%. The mean defs, on examination at aged 4 years was 0.4 +/-1.0 in group A, 0.7 +/-1.7 in group B and 1.4 +/-3.0 in group C. The difference between group A and C was statistically significant (p<0.05).

CONCLUSIONS

Less caries was observed in children of mothers who chewed gums with xylitol as the single sweetener during the time of eruption of the first primary teeth compared with those who used gums containing fluoride, sorbitol and lower amounts of xylitol.

Xylitol concentration in saliva and dental plaque after use of various xylitol-containing products

The study consisted of two sets of experiments, one in saliva and one in dental plaque. The xylitol concentration in saliva was determined enzymatically in 12 children (mean age 11.5 years) after a standardised use of various xylitol products: (A) chewing gums (1.3 g xylitol), (B) sucking tablets (0.8 g xylitol), (C) candy tablets (1.1 g xylitol), (D) toothpaste (0.1 g xylitol), (E) rinse (1.0 g xylitol), and (F) a non-xylitol paraffin. Unstimulated saliva was sampled 1, 3, 8, 16 and 30 min after use. The concentration in dental plaque was determined after mouthrinses with contrasting amounts of xylitol (LX = 2.0 g, HX = 6.0 g, and control) and supragingival plaque was collected and pooled after 5, 15 and 30 min. The mean xylitol concentration in saliva at baseline was approximately 0.1 mg/ml. All xylitol-containing products resulted in significantly increased levels (p < 0.05) immediately after intake and remained elevated for 8-16 min in the different groups. The highest mean value in saliva was obtained immediately after use of chewing gums (33.7 +/- 16.4 mg/ml) and the lowest was demonstrated after using toothpaste (8.2 +/- 4.9 mg/ml). No significant differences were demonstrated between chewing gums (A), sucking tablets (B), candy (C) and rinses (E). In dental plaque, the mean values were 8.6 +/- 5.4 and 5.1 +/- 4.0 mg/ml 5 min after HX and LX rinses. Concerning the higher concentration, the values remained significantly elevated (p < 0.05) during the entire 30-min follow-up. In conclusion, commonly advocated xylitol-containing products gave elevated concentrations of xylitol in unstimulated whole saliva and dental plaque for at least 8 min after intake.

Inhibition of enamel lesion formation by fluoridated milk assessed by laser fluorescence--an in vitro study

The aim of this study was to investigate the effect of fluoridated milk on enamel lesion formation as assessed by laser fluorescence (LF). The material consisted of 18 extracted premolar teeth that were cut in mesial-distal direction and pairwise assigned to either test or control samples in an experimental caries model. The teeth were exposed to a low-pH 5% cellulose gel for 4 h, 5 days per week immediately followed by a 4-h period in either fluoridated (5 ppm, test) or nonfluoridated milk (control). In the meantime, the specimens were stored in pooled human-stimulated whole saliva in room temperature. All teeth were examined by visual inspection with a magnifying glass and by LF readings (DIAGNOdent) at baseline and after 2 and 4 weeks. The baseline LF readings ranged from 3 to 7 with a mean value of 5.6+/-0.9. The mean values increased with time in both groups but the increase was more marked in the control teeth, 8.7+/-2.3 vs 12.8+/-3.3 after 4 weeks, this difference being statistically significant (p<0.01). The visual examination could not distinguish between the test or control samples after 2 and 4 weeks, respectively. The findings indicated that fluoride added to milk may to some extent counteract enamel lesion formation as assessed by LF in an experimental caries model.

Fluoride concentration in saliva after consumption of a dinner meal prepared with fluoridated salt

The aim was to determine the fluoride concentration in saliva after intake of a dinner meal prepared with fluoridated salt. The investigation had a randomized cross-over design, and 10 healthy adolescents with natural fluoride content (1.06 ppm) in their drinking water participated after informed consent. After a run-in week, the subjects were served a standardized dinner of spaghetti with minced meat sauce prepared with either fluoridated salt (test arm) or non-fluoridated salt (control arm). The fluoride concentration of the test salt was 250 ppm. Samples of stimulated whole saliva was collected at baseline, directly after eating (0 min) and then after 10, 30 and 180 min. After a 1-week wash-out period, the experimental procedure was repeated with the opposite salt. Fluoride concentration in saliva was measured with a fluoride-specific electrode and the post-ingestion levels were compared with baseline using repeated-measures ANOVA. The mean baseline concentrations were 10.9 and 8.0 microg/l in the test and control arms, respectively. Immediately after the intake, the mean fluoride values increased significantly to 81.6 microg/l in the test arm and to 31.5 microg/l in the control arm (p<0.05). The fluoride levels remained elevated (p<0.05) for 30 min after ingestion of the test meal but not following the control meal. In conclusion, consumption of a dinner meal prepared with fluoridated salt increased the salivary fluoride levels for about 30 min.

Eating habits, smoking and toothbrushing in relation to dental caries: a 3-year study in Swedish female teenagers

OBJECTIVES

The aims of the present study were to describe eating, toothbrushing and smoking habits in a cohort of Swedish female adolescents, and to relate the findings to dental caries increment.

DESIGN

The research took the form of a longitudinal study.

SUBJECTS AND METHODS

The study sample consisted of a cohort of 162 girls under regular dental care, aged 12 years at baseline, who were followed for 3 years, from the sixth to the ninth grade. Eating, oral cleaning and smoking habits were self-reported three times per year through a questionnaire, and caries data at baseline and after 3 years were collected from dental records.

RESULTS

The results showed significantly (P < 0.05) impaired eating habits during the study period and that adherence to regular main meals diminished. In the eighth grade, one-third of the girls skipped breakfast before school and only 50% had their free school lunch daily. The omission of breakfast and irregular main meals, as well as smoking were significantly associated with caries (decayed, missed and filled surfaces) increment in the eighth grade (odds ratio = 4.1-4.9, P < 0.05). Snacks, light meals, soft drinks and sweets were already frequently consumed at baseline and continued to be so over the years. Although > 95% of subjects reported that they brushed their teeth at least once a day, approximately 20% did not do it every evening, and this figure remained stable over the study period. However, snacks, soft drinks and sweets, and toothbrushing habits had no significant influence on caries development.

CONCLUSION

Dietary advice for caries prevention in adolescent girls should focus on the importance of retaining regular main meals, and especially, not skipping breakfast.

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.

Effects of furosemide and bendroflumethiazide on saliva flow rate and composition

Aim of this study was to evaluate the effect on saliva flow rate and composition and on perceived xerostomia. The study used a Latin square design, all subjects being once daily (at 7.00 a.m.) taking the bendroflumethiazide (2.5 mg), furosemide (40 mg), or placebo, in a randomised order. Each treatment period of 7 days was separated by wash-out periods of 14 days. Unstimulated and paraffin chewing stimulated whole saliva, and 3% citric acid stimulated parotid and submandibular-sublingual secretion were collected twice daily, at 7.30 a.m., with the patients in a fasting condition (morning values), and at 10.30 a.m., about 2 h after intake of a standard breakfast (lunchtime values), on day 0 (baseline), day 1 (acute treatment), and day 7 (chronic treatment). Saliva flow rates were measured and all four secretions were analysed for the concentration of sodium, potassium, chloride, and total protein. Xerostomia was assessed by means of a Visual Analogue Scale. Statistical analysis used the Wilcoxon signed rank test. For flow rate, only that of submandibular-sublingual secretion was affected, significantly so in the morning during chronic treatment with both drugs. In resting whole saliva the output of both sodium and chloride tended to decrease especially during treatment with bendroflumethiazide, while in submandibular-sublingual secretion the output of all the electrolytes was decreased, especially for potassium and chloride and during treatment with furosemide. Further, xerostomia tended to increase during treatment with furosemide, statistically significant at lunchtime during chronic treatment. In conclusion, this study has demonstrated a modest effect on salivary flow rate and a more pronounced effect on saliva composition, especially in submandibular-sublingual secretion during treatment of healthy volunteers with therapeutic doses of two different diuretics, encouraging clinical studies in hypertensive patients and basic research as to the presence of a thiazide sensitive Na-Cl cotransporter in human salivary glands.

Fluoride levels in saliva and dental plaque after consumption of snacks prepared with fluoridated salt

AIM

To determine the concentration of fluoride in saliva and supragingival dental plaque at designated time intervals after consumption of snacks prepared with a standardised amount of fluoridated salt.

STUDY DESIGN

The investigation had a single blind prospective crossover design.

METHODS

A group of 11 healthy young adults volunteered to participate after verbal and written information and consent. After a 1-week fluoride depletion period, the subjects consumed popcorn prepared with either fluoridated (250 mg/kg) or non-fluoridated salt during 30 minutes. Unstimulated whole saliva and samples of supragingival plaque were collected before consumption (baseline) and at 30, 60 and 120 minutes after the intake. Fluoride concentration was determined with a fluoride-specific electrode and the post-ingestion levels were compared with baseline by ANOVA.

RESULTS

In saliva, the mean fluoride concentrations at baseline ranged from 0.021 to 0.027 mg/L and after the 30 minutes consumption of fluoride prepared snacks a 15-fold increase (p<0.001) was found. The same pattern was disclosed in the plaque samples. In both saliva and plaque, the fluoride levels remained significantly elevated after 2 hours (p<0.001 and p<0.05, respectively).

CONCLUSION

Consumption of snacks prepared with fluoridated table salt resulted in significantly increased fluoride levels in saliva and supragingival plaque for a period of at least two hours.

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.

Prevalence of salivary Streptococcus mutans in mothers and in their preschool children

OBJECTIVES

To establish the prevalence and possible relationship of oral Streptococcus mutans colonization in mother-child pairs.

DESIGN AND SETTING

An analytical cross-sectional study was carried out at a well-baby evaluation clinic held at the Public Dental Clinic, Varberg, Sweden.

SAMPLE AND METHODS

Two hundred preschool children, 100 of which were 18 months old and the remaining 100 were 3 years old, and their mothers attended the clinic. All mothers were interviewed and their children's medical history, oral hygiene routines and dietary habits established. All children were clinically examined. The presence and level of S. mutans was estimated in the mother-child pairs with the aid of the Strip mutans chair-side test.

RESULTS

Nearly 50% of mothers exhibited high levels of salivary S. mutans, prevalence among the 18-month- and 3-year-olds was 30% and 42%, respectively. A statistically significant (P < 0.01) mother-child relationship was found; a greater presence in mothers led to a higher number of children found harbouring the bacteria. Logistic regression analysis found that high maternal S. mutans levels (P < 0.001), daily sweet intake (P < 0.01) and sugary drinks in feeding bottles (P < 0.05) were significant factors for S. mutans colonization in children. Absence of daily toothbrushing and use of feeding bottles at night failed to fit into the model. Caries prevalence (initial and manifest decayed surfaces) was significantly related to S. mutans colonization (P < 0.01).

CONCLUSION

The results support the concept of vertical transmission (mother-child), emphasizing the importance of the dietary component, and justifying a primary preventive approach with targeted action directed at mothers with high levels of S. mutans colonization.

Fluoride concentrations in saliva and dental plaque in young children after intake of fluoridated milk

This study determined fluoride (F) concentrations in whole saliva and dental plaque after intake of fluoridated milk using a randomised crossover experimental design. Eighteen healthy children (6-8 years) were subjected to each of four different 3-day drinking regimens: (a) 200 ml F-free tap water; (b) 200 ml tap water with 1.0 mg F; (c) 200 ml standard milk, and (d) 200 ml standard milk with 1.0 mg F. A washout period of 7 days was organised between the different drinking regimens. All children used F-free toothpaste prior to and during the trial and were instructed to avoid F-rich food and drinks. F concentration in unstimulated whole saliva was determined at baseline and after 15 and 120 min and in plaque samples at baseline and after 2 h. The mean baseline values ranged from 0.01 to 0.02 mg F/l in saliva and between 10.4 and 14.2 mg F/l in dental plaque. A statistically significant (p < 0.05) increase of F was disclosed in saliva 15 min after drinking F-containing milk and water (0.052 and 0.058 mg F/l, respectively). After 2 h, the salivary F(-) concentrations were back to baseline values. In the plaque, however, a statistically significant (p < 0.01) twofold increase was found at 2 h after the intake of fluoridated milk and water, respectively. The results indicate that consumption of fluoridated milk contributes to a F storing process with significantly elevated F concentrations in dental plaque up to 2 h after intake. Further studies are required to determine the 'therapeutic concentration' of F in dental plaque after intake of fluoridated milk.

Caries incidence in young type 1 diabetes mellitus patients in relation to metabolic control and caries-associated risk factors

The aim of this study was to evaluate the caries incidence in a group of young patients with type 1 diabetes mellitus over a 3-year period from the onset of the disease in relation to metabolic control and to caries-associated risk factors. Sixty-four children and adolescents (8-15 years of age) had their diabetes treated and monitored according to a standard medical protocol and received extensive preventive oral health care based on individual needs. Data on blood glucose and glycosylated haemoglobin (Hb A(Ic)) were collected from the medical records. Whole saliva was collected every 3rd month and secretion rate, buffer capacity, glucose concentration, mutans streptococci and lactobacilli counts were determined. Dental examinations, including radiographs, were carried out once a year. Patients with less good metabolic control (>8.0% Hb A(Ic)) exhibited higher glucose levels in resting saliva (p < 0.05) and a significantly higher caries incidence (p < 0.05) compared to those with good metabolic control. The most influential determinants for high caries development during the 3-year follow-up period were metabolic control (odds ratio, OR = 5.7), poor oral hygiene (OR = 6.5), previous caries experience (OR = 5.3) and high levels of salivary lactobacilli (OR = 5.0). The findings suggest that the level of metabolic control and traditional caries risk markers are important factors for caries development in children and adolescents with type 1 diabetes mellitus.

Application of quantitative light-induced fluorescence to monitor incipient lesions in caries-active children. A comparative study of remineralisation by fluoride varnish and professional cleaning

The aim of this study was to apply the quantitative light-induced fluorescence (QLF) method in a randomised controlled study, comparing treatment with fluoride varnish and professional tooth cleaning for remineralisation of white spot lesions in caries-active adolescents. In the fluoride varnish group (n = 13; 32 lesions), professional tooth-cleaning was followed by application of fluoride varnish at the beginning of the study, after 1 wk, and then once every 6 wk for 6 months. The other group (n = 18; 30 lesions) underwent professional tooth-cleaning once every 6 wk for 6 months. Enamel fluorescence was measured at baseline and at each visit. In the fluoride varnish group there was a significant change over time (baseline: 6 months) for both lesion area: and average change in fluorescence (decreased lesion area and increased fluorescence radiance). The corresponding changes in the professional tooth-cleaning group were not significant. There was a significant difference in average change in fluorescence between the two test groups. For lesion area, there was no significant difference, but a tendency towards a difference between the test groups. It was concluded that (a) the QLF method is a sensitive method, suitable for longitudinal quantification of incipient caries lesions on smooth surfaces; and (b) that repeated fluoride applications had a favourable effect on the remineralisation of white spot lesions as measured after 6 months.

Effect of an antibacterial varnish on lactic acid production in plaque adjacent to fixed orthodontic appliances

The effect of an antibacterial varnish on lactic acid concentration in suspensions of early supragingival plaque collected adjacent to fixed orthodontic brackets was evaluated in 25 adolescents using a double-blind split-mouth design with a placebo varnish control. The test varnish contained 1% chlorhexidine and 1% thymol as active ingredients. Both varnishes were applied on two occasions within 3 days and plaque was subsequently collected at 3, 7 and 30 days after the first treatment. The samples were evaluated for total viable counts (TVC) and the proportion of mutans streptococci. Acid fermentation in suspensions was induced by glucose and L(+)-lactic acid concentrations were determined enzymatically after a 30-min incubation period. The test varnish did not affect TVC but reduced the proportion of mutans streptococci significantly at the 7-day follow-up (P<0.05). The concentration of lactic acid was reduced by approximately 20% on the 3- and 7-day follow-ups (P<0.05). The results suggest that the chlorhexidine/thymol-containing varnish may to some extent reduce the viability and metabolic activity of susceptible oral bacteria in suspensions of early supragingival plaque.

Effect of a school-based preventive program with salivary lactobacillus counts as sugar-motivating tool on caries increment in adolescents

The caries preventive outcome of a school-based program with salivary; lactobacillus counts as sugar-motivating tool was evaluated in six cohorts of totally 936 adolescents in a comprehensive school in Sweden. Students from a neighboring district with similar socioeconomic structure but with no corresponding dental health-promoting activities were selected as reference. The program started in the beginning of the 7th grade (13 years) and was terminated at the end of the 9th grade (16 years). Salivary lactobacilli were evaluated semi-annually with a dip-slide method and used for individual counseling. Dental caries was scored from the dental records and bitewing radiographs of each 4th participant at baseline and at 16 and 19 years of age. The number of salivary lactobacilli decreased significantly (P< 0.05) in all cohorts but one during the program. There was no significant difference in the increment of caries (DFS) between the participants from the study and reference schools, either at the end of the program or at 19 years of age. The increment of proximal enamel caries was slightly lower in the study group compared with the reference group (P< 0.05) at the final registration. Considering the time and efforts spent, the results did not seem to justify a school-based intervention with lactobacillus counts as a sugar-motivating tool in an adolescent low-caries population.

Comparison of the efficacy of three different chlorhexidine preparations in decreasing the levels of mutans streptococci in saliva and interdental plaque

The aim of the present study was to evaluate and compare the effects of three different chlorhexidine (CHX)-containing preparations on mutans streptococci (MS) levels in interdental plaque and whole saliva. Ninety-three healthy school-children (8-10 years old) with high scores of salivary MS were selected by a screening procedure and randomised into three equally sized groups. MS were enumerated at all mesial interdental sites of the first permanent molars with aid of a modified chairside technique. The patients were then treated three times within 2 weeks with either a 1% CHX/thymol-containing varnish (group A) or a 1% CHX gel (group B), or they were subjected to daily supervised toothbrushing with a 0.4% CHX dentifrice for 1 month (group C). Follow-up samples of saliva and plaque from the interdental sites were collected 1 and 3 months after termination of treatment. A statistically significant reduction of MS levels in saliva and interdental plaque was found in all groups after 1 month. The CHX-containing dentifrice (group C) was the most effective method in reducing MS levels in saliva, and a significantly stronger (p < 0.05) suppression was found after 1 and 3 months when compared with the gel and the varnish forms. The gel (group B) tended to be slightly more effective than the varnish (group A). In the interdental plaque, the reduction of MS was less marked than in the saliva, and the three groups exhibited MS reductions of similar magnitude (20%) and duration, persisting up to 3 months. However, a high proportion (approximately 50%) of all interdental sites were relatively unaffected by the treatments. In conclusion, our results suggest that the interdental MS colonisation was difficult to combat, irrespective of CHX preparation and method, while the salivary levels were more easily affected. Daily tooth-brushing with a CHX-containing dentifrice was more effective in reducing MS in saliva compared with the gel or varnish applications.

Fluoride concentration in whole saliva and separate gland secretions in schoolchildren after intake of fluoridated milk

Fluoride concentration in whole saliva and in separate gland secretions was studied after a 7-day fluoridated milk regimen (1mg F per day) in 12 healthy schoolchildren aged 10-13 years. A 2-week fluoride-free run-in period preceded the tests in order to establish the endogenous baseline levels. Unstimulated and stimulated whole saliva and stimulated parotid and submandibular-sublingual saliva were collected at 1, 3, 6, 12 and 24h after F-milk ingestion, and fluoride concentrations were determined with an ion-selective electrode. Typical time-dependent excretion curves were obtained in all collected secretions. The fluoride levels were significantly elevated 1 and 3h in whole saliva and up to 6h in the gland secretions after intake of fluoridated milk when compared to baseline values. When acid-stimulated, the submandibular-sublingual glands were the major contributors of fluoride in the oral cavity. In conclusion, the results of this study demonstrate that fluoride ingested with milk is excreted through the salivary glands, indicating that the bioavailability of fluoride from milk equals that of other vehicles.

Infant oral health

According to the United Nations' Convention on "The Rights of the Child," articles 2 and 24, all children should have the same rights and have right to health and medical service. Early childhood caries is a lifestyle disease with biologic, behavioral, and social determinants. An early screening of all children at around 1 year of age is an excellent opportunity for early detection of risk factors and risk indicators that may increase the possibilities for its prevention. The caries risk evaluation should form the base for appropriate recommendations of preventive measures. The preventive care must be coordinated with an eventual operative care and should be based on education of prospective and new parents as well as professional and home-based measures. The various interventions must be developed further and evaluated in prospective studies in terms of effectiveness and efficiency for this specific age group. This is an urgent task for dental professionals and all societies with the ambition of providing good dental care for all young children.