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Topical Fluoride Varnish Every 6 Months is not More Effective Than Placebo Varnish at Preventing Dental Caries in Preschoolers in Brazil
DIAGNOSIS/TREATMENT/PROGNOSIS
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Biannual fluoride varnish applications and caries incidence in preschoolers: a 24-month follow-up randomized placebo-controlled clinical trial. Oliveira BH, Salazar M, Carvalho DM, Falcao A, Campos K, Nadanovsky P. Caries Res 2014;48(3):228-36
REVIEWER Donald L. Chi, DDS, PhD
PURPOSE/QUESTION To determine whether topical fluoride varnish applied every 6 months is more effective than a placebo varnish at preventing dental caries in preschoolers.
Topical Fluoride Varnish Every 6 Months is not More Effective Than Placebo Varnish at Preventing Dental Caries in Preschoolers in Brazil SUMMARY Subjects Children age 1 to 4 years (n = 100 in fluoride varnish arm and n = 100 in placebo varnish arm) attending a public health dental clinic for lowincome families in Rio de Janeiro, Brazil were recruited in 2006 and 2007. Children were excluded if they received fluoride varnish in the previous 6 months, had 10 or more tooth surfaces with dentin caries, presented with a dental abscess, or had a systemic disease that could be aggravated by caries. At baseline, 96.5% of children were exposed to fluoridated water, 79.5% brushed their teeth with fluoridated toothpaste, and 23.4% had at least 1 carious tooth surface. Children were examined at baseline and again at 24 months, at which time 89/100 children in the topical fluoride group and 92/100 children in the placebo group were included in the final intention-to-treat analyses.
Key Exposure/Study Factor SOURCE OF FUNDING
There were 2 study arms:
Government. Rio de Janeiro State Foundation for the Endowment of Research (FAPERJ; process E-26/ 102.248/2009) and the Brazilian National Research Council (CNPq; process 310807/2009). Industry: Colgate-Palmolive donated the placebo varnish, toothbrushes, and toothpaste
Fluoride Varnish Arm. Participants received 5% sodium fluoride varnish (Duraphat, Colgate Oral Pharmaceuticals, New York City, NY, USA) at baseline and subsequently every 6 months for 24 months (up to 4 fluoride varnish applications).
TYPE OF STUDY/DESIGN Randomized controlled trial
LEVEL OF EVIDENCE Level 2: Limited-quality, patientoriented evidence
STRENGTH OF RECOMMENDATION GRADE
Placebo Varnish Arm. The placebo varnish was provided by the same company that manufactured the fluoride varnish (Colgate Oral Pharmaceuticals). It was identical to the fluoride varnish except that it did not contain sodium fluoride. The varnish was applied to the participant’s teeth by a trained undergraduate or graduate dental student. For participants with a full primary dentition, a pea-sized dose of varnish was dispensed onto a paper pad and applied to the teeth. For participants with 10 or fewer teeth, about one-half of a pea-sized varnish dose was used. The teeth were isolated with cotton rolls and dried with compressed air. The varnish was applied to all tooth surfaces with a disposable microbrush. Parents were instructed to avoid brushing the child’s teeth and giving the child hard foods following varnish treatment. The fluoride and placebo varnish tubes were identical except that each type was labeled with letters (A or Z) by an individual not involved in the trial to maintain blinding. The dental examiners, students who applied the varnish, and study participants/parents were blinded to the varnish identity throughout the trial.
Not applicable J Evid Base Dent Pract 2014;14:142-144 1532-3382/$36.00 Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jebdp.2014.07.009
Main Outcome Measure The primary outcome was the proportion of children who developed new dentin caries after 24 months. Dentin caries incidence was
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
estimated by subtracting the total number of decayed, missing, and filled surfaces (d3mfs) at baseline from the total number of d3mfs at 24 months.
Main Results After 24 months, a larger proportion of children in the placebo varnish group (46.7%) had new dentin caries than children in the fluoride varnish group (35.9%), although the difference was not statistically significant (difference: 10.8; 95% confidence interval [CI]: 24.9, 3.3; p = 0.14).
Conclusions Application of fluoride varnish every 6 months for 2 years does not prevent primary tooth dentin caries incidence more effectively than a placebo varnish.
COMMENTARY AND ANALYSIS The rationale for this 24-month randomized placebocontrolled clinical trial was to evaluate the efficacy of fluoride varnish applied every 6 months in preschoolers to prevent early childhood caries (ECC). Based on trial results, the authors conclude that twice-yearly fluoride varnish failed to significantly reduce caries incidence compared with a placebo varnish. Overall, the study was well-designed and all checklist items were reported as recommended by the Consolidated Standards of Reporting Trials (CONSORT) Statement. However, there are two main limitations that should be addressed in future investigations on fluoride varnish. The first limitation, which the authors acknowledge, is the potential for a statistically underpowered study. There is insufficient justification for the proposed effect sizes used in the sample size calculations. It is unclear whether the anticipated caries incidence rates were based on preliminary data gathered from a similar study population or if the rates were extrapolated from other data sources. It is not possible to draw definitive conclusions based on an insufficiently powered trial, which highlights the need for additional prospective studies on fluoride varnish efficacy in preschool-aged children. The second limitation is the relatively high socioeconomic background of study participants. Study participants were recruited from low-income families within a public health dental clinic in Brazil. However, nearly all study participants had access to fluoridated water, large proportions of children brushed regularly with fluoride toothpaste, and the majority of participants in both the experimental and control group were of ‘‘medium socioeconomic status.’’ In fact, the baseline d3mfs rates of study participants in the fluoride varnish group (0.6 6 1.5) and the placebo group (1.0 6 2.0) were much lower than the dfs rate reported for US children Volume 14, Number 3
age 2–5 years (2.58 6 0.23) in the 1999–2004 National Health and Nutrition Examination Survey (NHANES).1 This gross comparison of baseline caries rates suggests that study participants may have been at low risk for ECC. Based on post-hoc exploratory analyses, the authors hypothesize that the ‘‘anticaries effect of [fluoride varnish] may be greatest in children with more sound dental surfaces than in children with active disease.’’ Under the assumption that the study population was at low risk for caries, the authors’ view may be misguided because it calls for suboptimal allocation of scarce public health resources and does not account for the fact that fluoride varnish is an unnecessary and costly treatment for low-risk children. Non risk-based application of fluoride varnish by dental professionals may have consequences, including topical fluoride hesitancy behaviors recently documented in parents.2 Restricting randomized clinical trials to caries-free preschoolers may result in similar problems of selection bias and limited external generalizability of study findings.3 Future placebocontrolled randomized trials should focus on high-risk preschoolers for whom fluoride varnish is clinically indicated. The US Preventive Services Task Force, the American Academy of Pediatrics, and the American Academy of Pediatric Dentistry endorse the application of fluoride varnish in young children even though there is only ‘‘moderate evidence’’ that fluoride varnish is efficacious at preventing ECC.4 In the context of existing US professional recommendations on fluoride varnish that are not fully evidence-based, ongoing implementation of the US Patient Protection and Affordable Care Act, and concomitant state-level Medicaid reform, there will be a continued need to strengthen the evidence base in favor of or against various preventive dental services for vulnerable populations, including fluoride varnish in preschoolers. This will require adequately powered, placebo-controlled randomized clinical trials that test the efficacy of fluoride varnish, effectiveness or pragmatic trials, and simulation studies based on methods from health economics that could help to guide future clinical trial work.5
REFERENCES 1. Dye BA, Tan S, Smith V, et al. Trends in oral health status: United States, 1988-1994 and 1999-2004. Vital Health Stat 11 2007; Apr(248):1-92. 2. Chi DL. Caregivers who refuse preventive care for their children: the relationship between immunization and topical fluoride refusal. Am J Public Health 2014;104(7):1327-33. 3. Weintraub JA, Ramos-Gomez F, Jue B, et al. Fluoride varnish efficacy in preventing early childhood caries. J Dent Res 2006;85(2): 172-6. 4. Marinho VC, Worthington HV, Walsh T, Clarkson JE. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 2013;7:CD002279.
143
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE 5. Chi DL, van der Goes DN, Ney JP. Cost-effectiveness of pit-and-fissure sealants on primary molars in Medicaid-enrolled children. Am J Public Health 2014;104(3):555-61.
REVIEWER Donald L. Chi, DDS, PhD Associate Professor, Department of Oral Health Sciences, University of Washington, Box 357475, Seattle, WA 9819507475, USA [email protected]
144
Adjunct Associate Professor, Department of Pediatric Dentistry, University of Washington, Box 357475, Seattle, WA 9819507475, USA Adjunct Associate Professor, Department of Health Services, University of Washington, Box 357475, Seattle, WA 9819507475, USA Adjunct Associate Professor, Department of Pediatrics, University of Washington, Box 357475, Seattle, WA 9819507475, USA
September 2014
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Biannual fluoride varnish applications and caries incidence in preschoolers: a 24-month follow-up randomized placebo-controlled clinical trial. Oliveira BH, Salazar M, Carvalho DM, Falcao A, Campos K, Nadanovsky P. Caries Res 2014;48(3):228-36
REVIEWER Donald L. Chi, DDS, PhD
PURPOSE/QUESTION To determine whether topical fluoride varnish applied every 6 months is more effective than a placebo varnish at preventing dental caries in preschoolers.
Topical Fluoride Varnish Every 6 Months is not More Effective Than Placebo Varnish at Preventing Dental Caries in Preschoolers in Brazil SUMMARY Subjects Children age 1 to 4 years (n = 100 in fluoride varnish arm and n = 100 in placebo varnish arm) attending a public health dental clinic for lowincome families in Rio de Janeiro, Brazil were recruited in 2006 and 2007. Children were excluded if they received fluoride varnish in the previous 6 months, had 10 or more tooth surfaces with dentin caries, presented with a dental abscess, or had a systemic disease that could be aggravated by caries. At baseline, 96.5% of children were exposed to fluoridated water, 79.5% brushed their teeth with fluoridated toothpaste, and 23.4% had at least 1 carious tooth surface. Children were examined at baseline and again at 24 months, at which time 89/100 children in the topical fluoride group and 92/100 children in the placebo group were included in the final intention-to-treat analyses.
Key Exposure/Study Factor SOURCE OF FUNDING
There were 2 study arms:
Government. Rio de Janeiro State Foundation for the Endowment of Research (FAPERJ; process E-26/ 102.248/2009) and the Brazilian National Research Council (CNPq; process 310807/2009). Industry: Colgate-Palmolive donated the placebo varnish, toothbrushes, and toothpaste
Fluoride Varnish Arm. Participants received 5% sodium fluoride varnish (Duraphat, Colgate Oral Pharmaceuticals, New York City, NY, USA) at baseline and subsequently every 6 months for 24 months (up to 4 fluoride varnish applications).
TYPE OF STUDY/DESIGN Randomized controlled trial
LEVEL OF EVIDENCE Level 2: Limited-quality, patientoriented evidence
STRENGTH OF RECOMMENDATION GRADE
Placebo Varnish Arm. The placebo varnish was provided by the same company that manufactured the fluoride varnish (Colgate Oral Pharmaceuticals). It was identical to the fluoride varnish except that it did not contain sodium fluoride. The varnish was applied to the participant’s teeth by a trained undergraduate or graduate dental student. For participants with a full primary dentition, a pea-sized dose of varnish was dispensed onto a paper pad and applied to the teeth. For participants with 10 or fewer teeth, about one-half of a pea-sized varnish dose was used. The teeth were isolated with cotton rolls and dried with compressed air. The varnish was applied to all tooth surfaces with a disposable microbrush. Parents were instructed to avoid brushing the child’s teeth and giving the child hard foods following varnish treatment. The fluoride and placebo varnish tubes were identical except that each type was labeled with letters (A or Z) by an individual not involved in the trial to maintain blinding. The dental examiners, students who applied the varnish, and study participants/parents were blinded to the varnish identity throughout the trial.
Not applicable J Evid Base Dent Pract 2014;14:142-144 1532-3382/$36.00 Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jebdp.2014.07.009
Main Outcome Measure The primary outcome was the proportion of children who developed new dentin caries after 24 months. Dentin caries incidence was
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
estimated by subtracting the total number of decayed, missing, and filled surfaces (d3mfs) at baseline from the total number of d3mfs at 24 months.
Main Results After 24 months, a larger proportion of children in the placebo varnish group (46.7%) had new dentin caries than children in the fluoride varnish group (35.9%), although the difference was not statistically significant (difference: 10.8; 95% confidence interval [CI]: 24.9, 3.3; p = 0.14).
Conclusions Application of fluoride varnish every 6 months for 2 years does not prevent primary tooth dentin caries incidence more effectively than a placebo varnish.
COMMENTARY AND ANALYSIS The rationale for this 24-month randomized placebocontrolled clinical trial was to evaluate the efficacy of fluoride varnish applied every 6 months in preschoolers to prevent early childhood caries (ECC). Based on trial results, the authors conclude that twice-yearly fluoride varnish failed to significantly reduce caries incidence compared with a placebo varnish. Overall, the study was well-designed and all checklist items were reported as recommended by the Consolidated Standards of Reporting Trials (CONSORT) Statement. However, there are two main limitations that should be addressed in future investigations on fluoride varnish. The first limitation, which the authors acknowledge, is the potential for a statistically underpowered study. There is insufficient justification for the proposed effect sizes used in the sample size calculations. It is unclear whether the anticipated caries incidence rates were based on preliminary data gathered from a similar study population or if the rates were extrapolated from other data sources. It is not possible to draw definitive conclusions based on an insufficiently powered trial, which highlights the need for additional prospective studies on fluoride varnish efficacy in preschool-aged children. The second limitation is the relatively high socioeconomic background of study participants. Study participants were recruited from low-income families within a public health dental clinic in Brazil. However, nearly all study participants had access to fluoridated water, large proportions of children brushed regularly with fluoride toothpaste, and the majority of participants in both the experimental and control group were of ‘‘medium socioeconomic status.’’ In fact, the baseline d3mfs rates of study participants in the fluoride varnish group (0.6 6 1.5) and the placebo group (1.0 6 2.0) were much lower than the dfs rate reported for US children Volume 14, Number 3
age 2–5 years (2.58 6 0.23) in the 1999–2004 National Health and Nutrition Examination Survey (NHANES).1 This gross comparison of baseline caries rates suggests that study participants may have been at low risk for ECC. Based on post-hoc exploratory analyses, the authors hypothesize that the ‘‘anticaries effect of [fluoride varnish] may be greatest in children with more sound dental surfaces than in children with active disease.’’ Under the assumption that the study population was at low risk for caries, the authors’ view may be misguided because it calls for suboptimal allocation of scarce public health resources and does not account for the fact that fluoride varnish is an unnecessary and costly treatment for low-risk children. Non risk-based application of fluoride varnish by dental professionals may have consequences, including topical fluoride hesitancy behaviors recently documented in parents.2 Restricting randomized clinical trials to caries-free preschoolers may result in similar problems of selection bias and limited external generalizability of study findings.3 Future placebocontrolled randomized trials should focus on high-risk preschoolers for whom fluoride varnish is clinically indicated. The US Preventive Services Task Force, the American Academy of Pediatrics, and the American Academy of Pediatric Dentistry endorse the application of fluoride varnish in young children even though there is only ‘‘moderate evidence’’ that fluoride varnish is efficacious at preventing ECC.4 In the context of existing US professional recommendations on fluoride varnish that are not fully evidence-based, ongoing implementation of the US Patient Protection and Affordable Care Act, and concomitant state-level Medicaid reform, there will be a continued need to strengthen the evidence base in favor of or against various preventive dental services for vulnerable populations, including fluoride varnish in preschoolers. This will require adequately powered, placebo-controlled randomized clinical trials that test the efficacy of fluoride varnish, effectiveness or pragmatic trials, and simulation studies based on methods from health economics that could help to guide future clinical trial work.5
REFERENCES 1. Dye BA, Tan S, Smith V, et al. Trends in oral health status: United States, 1988-1994 and 1999-2004. Vital Health Stat 11 2007; Apr(248):1-92. 2. Chi DL. Caregivers who refuse preventive care for their children: the relationship between immunization and topical fluoride refusal. Am J Public Health 2014;104(7):1327-33. 3. Weintraub JA, Ramos-Gomez F, Jue B, et al. Fluoride varnish efficacy in preventing early childhood caries. J Dent Res 2006;85(2): 172-6. 4. Marinho VC, Worthington HV, Walsh T, Clarkson JE. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 2013;7:CD002279.
143
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE 5. Chi DL, van der Goes DN, Ney JP. Cost-effectiveness of pit-and-fissure sealants on primary molars in Medicaid-enrolled children. Am J Public Health 2014;104(3):555-61.
REVIEWER Donald L. Chi, DDS, PhD Associate Professor, Department of Oral Health Sciences, University of Washington, Box 357475, Seattle, WA 9819507475, USA [email protected]
144
Adjunct Associate Professor, Department of Pediatric Dentistry, University of Washington, Box 357475, Seattle, WA 9819507475, USA Adjunct Associate Professor, Department of Health Services, University of Washington, Box 357475, Seattle, WA 9819507475, USA Adjunct Associate Professor, Department of Pediatrics, University of Washington, Box 357475, Seattle, WA 9819507475, USA
September 2014