**5. Meta-analysis**

The results of different estimations of the combined effect following the meta-analytic procedures with heterogeneous criteria, using the Dersimonian-Laird random effect model are shown in the metaview (7,8,14,17).

All procedures done to estimate the summary measure of effect, both as standardized mean difference and odds ratio, suggest that 440 to 550 ppm F toothpastes are not as effective in preventing dental caries in the primary and permanent dentition as pastes with 1000 ppm F or more.

Although the differences are statistically significant, the confidence intervals of all summary measures of effect are close to zero, both as standardized mean difference and odds ratio with the same results for the primary and permanent dentition.

homogeneity hypothesis was not rejected and no heterogeneity between the included

The estimated effect was measured in terms of average dental caries in each of the studied groups according to the dmf and DMF index. The final analysis evaluated the mean difference between the groups by applying the DerSimonian-Laird method for random

A metaview graphics illustrated the estimated values of the individual studies and the

Once the first meta-analytic approach was completed after combining the results from the independent studies, a sensibility analysis was done to establish the solidity of the combined estimated effect after one or more studies with extreme high or low values were

The data presented in the dental literature to answer the question of the efficacy of toothpastes with fluoride concentrations between 440 and 550 ppm in dental caries prevention in children are very limited. Four randomized controlled clinical trial were selected from five references yielded by electronic and hand searches. The studies included in the meta-analysis are listed in chronological order in Table 1. The included trials comprised a total of 5657 participants under similar conditions regarding variables, such as no systemic fluoridation and positive participation in oral health programs. Baseline caries levels were reported in all studies. Winter et al.(37) did not report specific baseline caries data. they explained that they decided to conduct the trial on 2-year-old children based on the expectation that most would be caries free given that according to epidemiological evidence very few children aged 2 years or less have caries which would be limited to the main lesions affecting the upper incisors. Of the 2177 children examined only 32 (1.5 per cent) had caries of this type with a difference of only 2 children between the groups. As a further analysis on the validity of the approach, they repeated the analysis of data related to

The results of different estimations of the combined effect following the meta-analytic procedures with heterogeneous criteria, using the Dersimonian-Laird random effect model

All procedures done to estimate the summary measure of effect, both as standardized mean difference and odds ratio, suggest that 440 to 550 ppm F toothpastes are not as effective in preventing dental caries in the primary and permanent dentition as pastes with 1000 ppm F

Although the differences are statistically significant, the confidence intervals of all summary measures of effect are close to zero, both as standardized mean difference and odds ratio

dental caries, omitting the 32 children, with no effect on the outcome.

with the same results for the primary and permanent dentition.

studies was considered.

combined estimated effect.

withdrawn from the meta analysis.

effects.

**4. Results** 

**5. Meta-analysis** 

or more.

are shown in the metaview (7,8,14,17).

Fig. 1. DMF-S and dmf-s in children under 14 years old: Metaview

Fig. 2. DMF-T and dmf-t in children under 14 years old: Metaview

Effect of 1000 or More ppm Relative

14.6 IC95% 11 a 32).

**6. Discussion** 

dental caries is diminished (29).

the most used in general population.

with 440 and 550 ppm F.

four were selected.

to 440 to 550 ppm Fluoride Toothpaste – A Systematic Review 197

Sensitivity Analysis: The study by Biesbrock et al.(6) was different in participation number with less weight than the other studies. Considering that this could influence the results, a sensitivity analysis was carried out by repeating the meta-analysis excluding this study. The odds ratio was not affected and the difference between the two groups was still significant

 Given that the results are in favor of toothpastes with 1000 ppm F or more, in dental caries prevalence reduction in children under 14 years old, the combined odds ratio was estimated again in order to determine the absolute risk reduction, assuming that these are more

Groups Dental caries Total OR - 95% CI

0.0002 Total 2434 2464 4898

According to these results there is a lower proportion of caries in children treated with dental toothpastes with 1000 ppm F or more, with an attributable risk factor of 0.0596 (6%) (p<0.00001). This demostrates how children under 14 years old using toothpastes with 1000 ppm F or more have approximately 6 percent more protection against caries than when they use toothpastes between 440 and 550 ppm F. To learn more about the impact and efficacy of this therapy the number needed to be treated to prevent one event was calculated (NNT=

Fluoride concentrations used in toothpastes are an important factor concerning toothpaste efficacy in reducing dental caries. Literature reviews such as the one done by Richards et al.(28) conclude that the optimal fluoride concentration in toothpaste is 1000 ppm F. This concentration has shown to provide best benefits in reducing dental caries and fluorosis. Meanwhile with fluoride concentrations less than 1000 ppm the efficacy in the reduction of

Recently, some meta-analysis has been published to describe the efficacy of different fluoride concentrations used in toothpastes to prevent dental caries in children and teenagers (1,20,21,33). However, none of them obtained conclusions regarding toothpastes

There were a limited number of studies comparing low F (440 to 550 ppm) to high F (1000 or more ppm) toothpastes. For this meta-analysis only five studies were found, out of which

The total sample size of children under 14 years old included in the 4 selected studies was 5657, the fluoride compounds in the toothpastes used were sodium fluoride in 440, 500, 550 and 1450 ppm; and sodium monofluorophosphate in 1000, 1055 and 1450 ppm, as they are

0.76 (0.66 – 0.88)

effective than those with 440 and 550 ppm F in dental caries prevention (see Table 3).

Yes No

Fluoride 440 to 550 ppm 1290 1159 2449 *p* value:

Fluoride > 1000 ppm 1144 1305 2449

Table 3. Summary estimate of odds ratio. random-effects model.

(OR: 1.28 - CI95%: 1.13 to 1.44) in favor of toothpastes with 1000 ppm F or more.

Fig. 3. dmf-t index in children under 6 years old: Metaview.

Fig. 4. Odds ratios to dental caries prevalence in children under 14 years old: Metaview.

Sensitivity Analysis: The study by Biesbrock et al.(6) was different in participation number with less weight than the other studies. Considering that this could influence the results, a sensitivity analysis was carried out by repeating the meta-analysis excluding this study. The odds ratio was not affected and the difference between the two groups was still significant (OR: 1.28 - CI95%: 1.13 to 1.44) in favor of toothpastes with 1000 ppm F or more.

 Given that the results are in favor of toothpastes with 1000 ppm F or more, in dental caries prevalence reduction in children under 14 years old, the combined odds ratio was estimated again in order to determine the absolute risk reduction, assuming that these are more effective than those with 440 and 550 ppm F in dental caries prevention (see Table 3).



According to these results there is a lower proportion of caries in children treated with dental toothpastes with 1000 ppm F or more, with an attributable risk factor of 0.0596 (6%) (p<0.00001). This demostrates how children under 14 years old using toothpastes with 1000 ppm F or more have approximately 6 percent more protection against caries than when they use toothpastes between 440 and 550 ppm F. To learn more about the impact and efficacy of this therapy the number needed to be treated to prevent one event was calculated (NNT= 14.6 IC95% 11 a 32).
