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Teacher-supervised toothbrushing with fluoride has little effect on dental caries prevention
THERAPY
A RTICLE A NALYSIS &
Teacher-supervised toothbrushing with fluoride has little effect on dental caries prevention
E VALUATION Original Article
Jackson RJ, Newman HN, Smart GJ, Stokes E, Hogan JI, Brown C, et al. The effects of a supervised toothbrushing programme on the caries increment of primary school children, initially aged 5-6 years. Caries Res 2005;39(2):108-15.
Level of Evidence
2b
Purpose/Question
Does teacher-supervised toothbrushing with 1450 ppm fluoride toothpaste during the school term decrease caries incidence in primary-school children?
Source of Funding
Associations from the sugar industry
Type of Study/Design
Randomized controlled trial
Summary SUBJECTS The study population was primary school children aged 5 to 6 years living in Kensington, Chelsea, and Westminster-London, UK, where the fluoride concentration in drinking water was less than 0.3 ppm. Their baseline caries experience was 6.92 DMFS+dmfs. The study was carried out between September 2000 and July 2002. THERAPY Children in the intervention group (n = 259) brushed their teeth once a day with 1450 ppm fluoride toothpaste under teachers’ supervision during the school term for 21 months. Teachers received instructions
J Evid Base Dent Pract 2005;5:202-4 D 2005 Mosby, Inc. All rights reserved. doi:10.1016/j.jebdp.2005.09.009
202
from a dental hygienist in toothbrushing techniques for young children at the beginning of the study. Children in the control group (n = 258) did not receive any dental health education program or fluoride toothpaste.
MAIN OUTCOME MEASURE The incidence of DMFS + dmfs (decayed, missing, and filled surfaces in the permanent and primary dentition) was assessed by visual examination using the BASCD (British Association for the Study of Community Dentistry) criteria. Surfaces were considered sound if no treatment had been performed or untreated caries into dentine were present. Surfaces were considered decayed if there was a lesion into dentine. Subgroup analyses were performed for primary teeth, permanent teeth, and by type of tooth surface (interproximal, occlusal, and smooth).
MAIN RESULTS The caries incidence in permanent and primary tooth surfaces combined for the toothbrushing and the control groups was 2.60 DMFS + dmfs (95% Confidence Interval [CI]: 1.84-3.36) and 2.92 DMFS + dmfs (95% CI: 2.183.66), respectively. The caries incidence was reduced by 12% in the primary dentition (mean difference= -0.33 dmfs, P = .001) and by 21.4% in the interproximal surfaces (mean difference= -0.25 DMFS + dmfs, P b .01). No effect was observed on the permanent dentition or in the occlusal and smooth surfaces. CONCLUSIONS Teacher-supervised toothbrushing with fluoridated toothpaste was associated with a modest decrement in caries incidence, mainly in primary teeth and interproximal surfaces.
Commentary and Analysis Since the introduction of water fluoridation more than 5 decades ago, fluoride therapy in one form or another has been the major caries-preventive strategy. In the past 25 years toothbrushing with fluoride toothpaste has become the most common delivery for topical fluorides. This randomized clinical trial (RCT) evaluated the effect of a caries-preventive program based on teachersupervised toothbrushing with fluoride toothpaste in primary schoolchildren. Strengths of this RCT include the evaluation of topical fluorides in the actual conditions of low caries incidence and almost universal access to fluoride dentifrices. Although the caries-preventive effect of topical fluorides, and specifically of fluoridated toothbrushing in children is well known,1 this evidence is based on studies performed before 1990 when caries levels were higher and access to fluoride toothpaste more limited. The reviewed study was performed in a community where the mean dmft of 5-year-old children was 2.83 in 1997/1998. All children were exposed to some level of topical fluoride, since 97% of UK children 1.5 to 4.5 years old had fluoridated toothpaste at home.2 One important feature of this RCT is the outcome. The assessment of a meaningful end point–caries into dentine–increased the reliability of the results, since diagnosing caries into dentine is less prone to observation bias (which was confirmed by the excellent agreement among examiners in the reviewed study). This randomized clinical trial has several limitations in the design and analyses. First, the randomization method was unclear. The reported unit of randomization was the school but only the number of children in each group was reported. If only a small number of
Journal of Evidence-Based Dental Practice Volume 5, Number 4
schools were randomized, the RCT lacked statistical power to identify an intervention effect. Furthermore, the correlation within groups, ie, children within schools, should have been considered in the data analysis. If children were the unit of randomization, children in the control group might have received some benefits from the supervised fluoride toothbrushing since they were in the same school or even in the same class of the children in the intervention group and contamination of the intervention cannot be ruled out. Second, the reported statistical analyses and results are unclear and confusing. Replication of the results using a two-sample t test based on the reported confidence intervals indicates nonsignificant differences, while the authors reported highly significant results. For instance, the estimated P value for the difference in caries incidence for the primary results yielded a nonsignificant P value of .55, which is in stark contrast with the reported P value of .001 (see Table 3 in the reviewed article). It is puzzling that standard statistical methods could not replicate the results of the RCT. More information is needed to confirm the statistical significance of the results. The final concern relates to the high dropout rate. More then 25% of the children were not present at the final examination. The authors correctly addressed this by reporting the baseline characteristics of those who completed the study and analyzing only the available cases. Even so, in these circumstances the randomization method cannot be guaranteed and the potential for biased results increases. In addition to these methodological concerns, the study was sponsored by the Biscuit, Chocolate and Confectionary Association; the British Soft Drinks Association; and The Sugar Bureau. These associations have interests in showing the efficacy of oral hygiene and fluoride interventions in order to circumvent the necessity of diet interventions to reduce sugar consumption. Evidence of an independent data and safety monitoring board for this trial could have alleviated concerns regarding potential conflicts of interest. The primary conclusion of the study—that daily teacher-supervised toothbrushing with fluoride toothpaste significantly reduced dental caries—does not appear to be supported by the reported data. Even if the results were statistically significant, the magnitude of the reduction in caries incidence is of questionable clinical relevance. A strength of this report is that the observed 10.9% caries reduction was consistent with the results of a systematic review on topical fluorides when comparing supervised versus unsupervised toothbrushing with fluoride toothpaste.1 These findings suggest that more intensive use of fluoridated
Jackson et al 203
toothpaste under supervision can only contribute to a modest caries reduction. In conclusion, the reviewed RCT corroborates the conclusions of other studies3,4 and suggests limited benefits of oral health programs with topical fluorides above and beyond the actual exposure to topical fluorides through toothbrushing at home. Evaluation of different caries-preventive strategies with emphasis on a population approach,5 such as reducing the frequency of sugar intake6 should be encouraged to minimize the caries burden in children. REFERENCES 1. Marinho VC, Higgins JP, Sheiham A, Logan S. Fluoride toothpastes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 1999;1:CD002278. 2. Gibson S, Williams S. Dental caries in pre-school children: associations with social class, toothbrushing habit and consumption of sugars and sugar-containing foods. Further analysis of data from
204
Jackson et al
3. 4. 5. 6.
the National Diet and Nutrition Survey of children aged 1.5-4.5 years. Caries Res 2003;33(2):101-13. Kallestal C. The effect of five years’ implementation of cariespreventive methods in Swedish high-risk adolescents. Caries Res 2005;39(1):20-6. Hausen H, Karkkainen S, Seppa L. Application of the high-risk strategy to control dental caries. Community Dent Oral Epidemiol 2000;28(1):26-34. Batchelor P, Sheiham A. The limitations of a ‘high-risk’ approach for the prevention of dental caries. Community Dent Oral Epidemiol 2002;30(4):302-12. Sheiham A. Dietary effects on dental diseases. Public Health Nutr 2001;4(2B):569-91.
Reviewer: Joana Cunha-Cruz, MPH Social Medicine Institute State University of Rio de Janeiro, Brazil Visiting Research Scientist University of Washington Dental Public Health Sciences Seattle, Washington
Journal of Evidence-Based Dental Practice December 2005
A RTICLE A NALYSIS &
Teacher-supervised toothbrushing with fluoride has little effect on dental caries prevention
E VALUATION Original Article
Jackson RJ, Newman HN, Smart GJ, Stokes E, Hogan JI, Brown C, et al. The effects of a supervised toothbrushing programme on the caries increment of primary school children, initially aged 5-6 years. Caries Res 2005;39(2):108-15.
Level of Evidence
2b
Purpose/Question
Does teacher-supervised toothbrushing with 1450 ppm fluoride toothpaste during the school term decrease caries incidence in primary-school children?
Source of Funding
Associations from the sugar industry
Type of Study/Design
Randomized controlled trial
Summary SUBJECTS The study population was primary school children aged 5 to 6 years living in Kensington, Chelsea, and Westminster-London, UK, where the fluoride concentration in drinking water was less than 0.3 ppm. Their baseline caries experience was 6.92 DMFS+dmfs. The study was carried out between September 2000 and July 2002. THERAPY Children in the intervention group (n = 259) brushed their teeth once a day with 1450 ppm fluoride toothpaste under teachers’ supervision during the school term for 21 months. Teachers received instructions
J Evid Base Dent Pract 2005;5:202-4 D 2005 Mosby, Inc. All rights reserved. doi:10.1016/j.jebdp.2005.09.009
202
from a dental hygienist in toothbrushing techniques for young children at the beginning of the study. Children in the control group (n = 258) did not receive any dental health education program or fluoride toothpaste.
MAIN OUTCOME MEASURE The incidence of DMFS + dmfs (decayed, missing, and filled surfaces in the permanent and primary dentition) was assessed by visual examination using the BASCD (British Association for the Study of Community Dentistry) criteria. Surfaces were considered sound if no treatment had been performed or untreated caries into dentine were present. Surfaces were considered decayed if there was a lesion into dentine. Subgroup analyses were performed for primary teeth, permanent teeth, and by type of tooth surface (interproximal, occlusal, and smooth).
MAIN RESULTS The caries incidence in permanent and primary tooth surfaces combined for the toothbrushing and the control groups was 2.60 DMFS + dmfs (95% Confidence Interval [CI]: 1.84-3.36) and 2.92 DMFS + dmfs (95% CI: 2.183.66), respectively. The caries incidence was reduced by 12% in the primary dentition (mean difference= -0.33 dmfs, P = .001) and by 21.4% in the interproximal surfaces (mean difference= -0.25 DMFS + dmfs, P b .01). No effect was observed on the permanent dentition or in the occlusal and smooth surfaces. CONCLUSIONS Teacher-supervised toothbrushing with fluoridated toothpaste was associated with a modest decrement in caries incidence, mainly in primary teeth and interproximal surfaces.
Commentary and Analysis Since the introduction of water fluoridation more than 5 decades ago, fluoride therapy in one form or another has been the major caries-preventive strategy. In the past 25 years toothbrushing with fluoride toothpaste has become the most common delivery for topical fluorides. This randomized clinical trial (RCT) evaluated the effect of a caries-preventive program based on teachersupervised toothbrushing with fluoride toothpaste in primary schoolchildren. Strengths of this RCT include the evaluation of topical fluorides in the actual conditions of low caries incidence and almost universal access to fluoride dentifrices. Although the caries-preventive effect of topical fluorides, and specifically of fluoridated toothbrushing in children is well known,1 this evidence is based on studies performed before 1990 when caries levels were higher and access to fluoride toothpaste more limited. The reviewed study was performed in a community where the mean dmft of 5-year-old children was 2.83 in 1997/1998. All children were exposed to some level of topical fluoride, since 97% of UK children 1.5 to 4.5 years old had fluoridated toothpaste at home.2 One important feature of this RCT is the outcome. The assessment of a meaningful end point–caries into dentine–increased the reliability of the results, since diagnosing caries into dentine is less prone to observation bias (which was confirmed by the excellent agreement among examiners in the reviewed study). This randomized clinical trial has several limitations in the design and analyses. First, the randomization method was unclear. The reported unit of randomization was the school but only the number of children in each group was reported. If only a small number of
Journal of Evidence-Based Dental Practice Volume 5, Number 4
schools were randomized, the RCT lacked statistical power to identify an intervention effect. Furthermore, the correlation within groups, ie, children within schools, should have been considered in the data analysis. If children were the unit of randomization, children in the control group might have received some benefits from the supervised fluoride toothbrushing since they were in the same school or even in the same class of the children in the intervention group and contamination of the intervention cannot be ruled out. Second, the reported statistical analyses and results are unclear and confusing. Replication of the results using a two-sample t test based on the reported confidence intervals indicates nonsignificant differences, while the authors reported highly significant results. For instance, the estimated P value for the difference in caries incidence for the primary results yielded a nonsignificant P value of .55, which is in stark contrast with the reported P value of .001 (see Table 3 in the reviewed article). It is puzzling that standard statistical methods could not replicate the results of the RCT. More information is needed to confirm the statistical significance of the results. The final concern relates to the high dropout rate. More then 25% of the children were not present at the final examination. The authors correctly addressed this by reporting the baseline characteristics of those who completed the study and analyzing only the available cases. Even so, in these circumstances the randomization method cannot be guaranteed and the potential for biased results increases. In addition to these methodological concerns, the study was sponsored by the Biscuit, Chocolate and Confectionary Association; the British Soft Drinks Association; and The Sugar Bureau. These associations have interests in showing the efficacy of oral hygiene and fluoride interventions in order to circumvent the necessity of diet interventions to reduce sugar consumption. Evidence of an independent data and safety monitoring board for this trial could have alleviated concerns regarding potential conflicts of interest. The primary conclusion of the study—that daily teacher-supervised toothbrushing with fluoride toothpaste significantly reduced dental caries—does not appear to be supported by the reported data. Even if the results were statistically significant, the magnitude of the reduction in caries incidence is of questionable clinical relevance. A strength of this report is that the observed 10.9% caries reduction was consistent with the results of a systematic review on topical fluorides when comparing supervised versus unsupervised toothbrushing with fluoride toothpaste.1 These findings suggest that more intensive use of fluoridated
Jackson et al 203
toothpaste under supervision can only contribute to a modest caries reduction. In conclusion, the reviewed RCT corroborates the conclusions of other studies3,4 and suggests limited benefits of oral health programs with topical fluorides above and beyond the actual exposure to topical fluorides through toothbrushing at home. Evaluation of different caries-preventive strategies with emphasis on a population approach,5 such as reducing the frequency of sugar intake6 should be encouraged to minimize the caries burden in children. REFERENCES 1. Marinho VC, Higgins JP, Sheiham A, Logan S. Fluoride toothpastes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 1999;1:CD002278. 2. Gibson S, Williams S. Dental caries in pre-school children: associations with social class, toothbrushing habit and consumption of sugars and sugar-containing foods. Further analysis of data from
204
Jackson et al
3. 4. 5. 6.
the National Diet and Nutrition Survey of children aged 1.5-4.5 years. Caries Res 2003;33(2):101-13. Kallestal C. The effect of five years’ implementation of cariespreventive methods in Swedish high-risk adolescents. Caries Res 2005;39(1):20-6. Hausen H, Karkkainen S, Seppa L. Application of the high-risk strategy to control dental caries. Community Dent Oral Epidemiol 2000;28(1):26-34. Batchelor P, Sheiham A. The limitations of a ‘high-risk’ approach for the prevention of dental caries. Community Dent Oral Epidemiol 2002;30(4):302-12. Sheiham A. Dietary effects on dental diseases. Public Health Nutr 2001;4(2B):569-91.
Reviewer: Joana Cunha-Cruz, MPH Social Medicine Institute State University of Rio de Janeiro, Brazil Visiting Research Scientist University of Washington Dental Public Health Sciences Seattle, Washington
Journal of Evidence-Based Dental Practice December 2005