Fluoride-containing gels, mouth rinses and varnishes: an update of evidence of efficacy.
Fluoride (F) is the cornerstone in the prevention of dental caries, and a number of methods and technologies for application of different F compounds to the tooth surface have been developed. The purpose of this paper was to update existing systematic reviews on the efficacy of 3 of these technologies: Gels, Mouth rinses and Varnishes. Important clinical characteristics of these technologies vary (Table 1). As can be seen, the philosophy varies both concerning the cariostatic mechanisms of F, as reflected in contact time and concentration, and in the practical implementation in the field, including the personnel required. Economy and feasibility of the methods are other factors that may influence the choice between different methods. Finally, tradition and the biases of influential professionals in the field will also be important predictors. In the present paper, only efficacy has been considered, understood as "the extent to which an intervention produces a beneficial result under ideal conditions" [Cohrane collaboration, 2005], although there is no doubt that other factors than efficacy are just as important determinants for the choice of topical F.
The starting point for this update was the 3 systematic Cochrane reviews on gels [Marinho et al., 2002a], mouth rinses [Marinho et al., 2003] and varnishes [Marinho et al., 2002b], and a report from The Swedish Council on Technology Assessment in Health Care . The full report was written in Swedish, but with a brief summary in English, and the reviews on mouth rinses and varnish have subsequently been published in English [Petersson et al., 2004; Twetman et al., 2004].
The literature search was performed using a search string similar to one of the search strings used in the Cochrane reviews ("A supplementary and more specific subject search phrase..."). The following databases were searched: PubMed 2000 to 2008, EMBASE 2000-2009, Cochrane 2000-2008. A detailed description of the search methodology can be obtained from the author. Titles and abstracts of papers, which on the basis of the title could be described, as clinical trials were further scrutinized, and only randomized or semi-randomized controlled trials were included. The criteria for exclusion or inclusion of studies were similar to those used in the Cochrane reviews, e.g. only studies where the intervention group (gels, mouth rinses or varnish) was compared with a non-intervention or a placebo-treated group and were included. As F-toothpaste is commonly used in most European populations, any effect of F gels, mouth rinses and varnish were added to the effect of F-toothpaste. Such studies were thus included in this review update. Studies where, for example, F varnish was compared with fissure sealants were not included.
Only those studies in which the endpoint was clinically or radiologically diagnosed caries, either at the non-cavitation level or at the cavitation level (reported as DMFS--or DMFT-increments from baseline) for coronal caries were included. Studies that only reported on arrestment of existing lesions were excluded. Only studies in children and adolescents were included, and studies on special types of patients (e.g. special needs patients, orthodontic patients etc.) were excluded. Abstracts were excluded, and only papers written in English or German were included.
There were 6 papers reporting on 4 trials on gels [ Madlena et al., 2002; van Rijkom et al., 2004; Jiang et al., 2005; Truin and van't Hof, 2005a; Truin and van't Hof, 2005b; Truin and van't Hof, 2007], 1 reporting on the effect of mouthrinses [Skold et al., 2005a], and 6 reporting on the effect of varnish [Zimmer et al., 2001; Bravo et al., 2005; Skold et al. 2005b; Borutta et al., 2006; Weintraub et al., 2006; Hardman et al. 2007], which fulfilled the inclusion criteria. The number of studies reporting on efficacy in the primary dentition was limited; 1 for gels [van Rijkom et al., 2004], none for rinses, and 3 for varnishes [Borutta et al., 2006; Weintraub et al., 2006; Hardman et al., 2007] A summary of the studies is given in Tables 2 to 4.
Gels. The follow-up period for the studies on gels varied from 2 to 4 years, and 3 of 4 trials were reported to be blinded, although a placebo was not always included [Jiang et al., 2005]. One of the studies used APF [Jiang et al., 2005], one used Elmex Gel [Madlena et al., 2002], and 2 of the studies used a sodium fluoride gel [Truin and van't Hof, 2005b; Truin and van't Hof, 2007; van Rijkom et al., 2004]. Prevented fraction of caries ranged from18% [Truin and van't Hof., 2005b] to 41% [Jiang et al., 2005]. Inclusion of initial caries lesions did not result in any large change of the estimates [Truin and van't Hof, 2005a; Truin and van't Hof, 2007]. In spite of finding most of the studies resulted in treatment effects which were statistically significant at the 5% level, the clinical relevance of the effect was questioned by some of the authors [Truin and van't Hof, 2005a; van Rijkom et al., 2004]. The only studies which allowed a direct comparison of gels with different fluoride compounds did not show any difference in efficacy [Jiang et al., 2005].
Mouth rinses. Only one study on the effect of F rinses was identified [Skold et al., 2005a]. This study was conducted on 13-16 year old children, had a follow-up period of 3 years, and was based exclusively on radiographic diagnosis of approximal caries. There were 4 different rinsing schedules tested against a no-rinse control group. The rinsing solution was 0.2% sodium fluoride, and PF-values of 30% to 59% were found. Statistically significant differences were found between the control, and 1: rinses first 3 schooldays each semester; 2: first and last 3 schooldays each semester; 3: 3 consecutive days once a month; and 4: every fortnight.
Varnishes. Of the 6 papers reporting on the effect of F containing varnishes, one had a follow-up period of 4 years [Bravo et al., 2005], with varnish applications every 6th month. The other 5 studies had follow-up periods of 2 or 3 years [Zimmer et al., 2001; Bravo et al., 2005; Skold et al., 2005b; Borutta et al., 2006; Weintraub et al., 2006; Hardman et al., 2007]. Of these studies 3 used 5% sodium fluoride varnish [Bravo et al., 2005; Skold et al., 2005b; Weintraub et al., 2006], while the fourth used a 0.1% 'fluoride varnish' [Zimmer et al., 2001]. PF-values ranged from 34% to 57% with P-values of < 0.05 for most of the estimates.
The review of the literature indicates that recent F containing gels, mouth rinses and varnishes have a caries-preventive effect. In spite of differences in intervention (e.g. frequency and concentration), diagnostic methods and diagnostic criteria, there seems to be limited variation in the estimates of the prevented fraction. This however needs to be substantiated by a formal analysis of homogeneity of the studies.
Only limited number of the studies identified in the literature search fulfilled the inclusion criteria, mainly because they did not have a no-treatment or placebo-treated control group. This indicates that researchers have become more interested in comparing different preventive technologies (such as topical F and fissure sealants), than in estimating the effect of single procedures.
The review from The Swedish Council on Technology Assessment in Health Care  concluded that the effect of APF gels was well established, while the effect of neutral sodium F gels was not. The present review seems to indicate that the lack of studies on neutral sodium fluoride gels has now been met. The Cochrane Review on F gels found a PF of 28% (95% C.I.: 14% to 37%) [Marinho et al., 2002a], which seems to be consistent with the estimates of PF fraction found in most of the trials included in this review.
The Swedish review on the effect of F mouth rinses concluded that F rinses have a caries-preventive effect in children with limited exposure to F from other sources such as toothpaste [Twetman et al., 2004]. However, very limited recent data on oral hygiene habits and the use of F-tooth paste are available. The estimate of effect obtained in The Cochrane Review [Marinho et al., 2003] was of 26% (95% C.I.: 23% to 30%), which is somewhat lower that the estimate obtained in this review.
Regarding F varnishes, the results obtained in the present review agreed relatively well with the conclusion reached in the Swedish review, and the estimate obtained in The Cochrane Review of a PF of 46% (95% C.I: 30% to 63%) [Marinho et al., 2002b]. An important methodological observation is, however, that none of the varnish-trials were placebo-controlled, as non-placebo-controlled trials tend to overestimate efficacy.
The shortage of high quality trials on efficacy of these F application methods in the primary dentition is notable. In the case of F varnish, only 3 trials reported on efficacy in the primary teeth, of which 2 found an effect [Borutta et al., 2006; Weintraub et al., 2006], while one was not able to demonstrate an effect [Hardiman et al. 2007]. In the light of the popularity of F varnishes among clinicians, the need for more high quality clinical trails on the efficacy of these methods in preventing caries in the primary dentition is obvious.
The present review has further substantiated the evidence obtained in previously published systematic reviews, indicating that fluoride containing gels, mouth rinses and varnishes all seem to have a caries-preventive effect. No data are available to allow a comparison of the efficacy of the three interventions.
The assistance of Research Librarian Janne Lystoft Simonsen, M.Sc., Ph.D., Library of Health Sciences, Aarhus University in developing the literature search profile is highly appreciated. The assistance of V. C. C. Marinho in securing an update of the references is also appreciated.
Borutta A, Reuscher G, Hufnagl S, Moblus, S. Caries Prevention with Fluoride Varnishes among Preschool Children (Swedish). Gesundheitwesen 2006;68:731-734.
Bravo M, Montero JJ, Bravo JJ, Baca P, Llodra JC. Sealant and fluoride varnish in caries: a randomized trial. J Dent Res 2005;84:1138-1143.
Cochrane Collaboration. Glossary of Terms in the Cochrane Collaboration, version 4.2.5. Cochrane Collaboration.2005.
Hardman MC, Davies GM, Duxbury JT, Davies, RM. A cluster randomised controlled trial to evaluate the effectiveness of fluoride varnish as a public health measure to reduce caries in children. Caries Res 2007;41:371-376.
Jiang H, Tai BJ, Du MQ, Peng B.Effect of professional application of APF foam on caries reduction in permanent first molars in 6-7-year old children: 24-month clinical trial. J Dent 2005;33:469-473.
Madlena M, Nagy G, Gabris K, et al. Effect of amine fluoride toothpaste and gel in high risk groups of Hungarian adolescents: Results of a longitudinal study. Caries Res 2002;36:142-148.
Marinho VCC, Higgins J P T, Logan S, Sheiham A., Fluoride gels for preventing dental caries in children and adolescents (Review). Cochrane Database of Systematic Reviews DOI: 10.1002/14651858.CDO002280. 2002a
Marinho VCC, Higgins JPT, Logan S, Sheiham A. Fluoride mouthrinses for preventing dental caries in children and adolescents (Review), Cochrane Database of Systematic Reviews 2003 DOI: CD002284-14651858. CDO002284.
Marinho VCC, Higgins JPT, Logan S, Sheiham A., Fluoride varnishes for preventing dental caries in children and adolescents (Review). Cochrane Database of Systematic Reviews 2002b DOI: 10.1002/4651858. CDO002279.
Petersson LG, Twetman S, Dahlgren H, et al. Professional fluoride varnish treatment for caries control: a systematic review of clinical trials. Acta Odontol Scand 2004;62:170-176..
Skold UM, Birkhed D, Borg E, Petersson, LG. Approximal caries development in adolescents with low to moderate caries risk after different 3-year school-based supervised fluoride mouth rinsing programmes. Caries Res 2005a;39:529-535.
Skold UM, Petersson LG, Lith A, Birkhed D. Effect of school-based fluoride varnish programmes on approximal caries in adolescents from different risk areas. Caries Res 2005b;39:273-279.
The Swedish Council on Technology Assessment in Health Care. Att forebygga karies. En systematisk litteraturoversikt. Report nr. 161 SBU. Statens beredning for medicinsk utvardering, Stockholm 2002.
Truin GJ, van't Hof MA. Caries prevention by professional fluoride gel application on enamel and dentinal lesions in low-caries children. Caries Res 2005a;39:236-240.
Truin GJ, van't Hof MA., Professionally applied fluoride gel in low-caries 10.5 year olds. J Dent Res 2005b;84:418-421.
Truin GJ, van't Hof MA. The effect of fluoride gel in incipient lesions in a low-caries child population. Community Dent Oral Epidemiol 2007;35:250 254.
Twetman S, Petersson LG, Axelsson S, et al. Caries-preventive effect of sodium fluoride mouthrinses: a systematic review of controlled clinical trials. Acta Odontol Scand 2004;62:223-230.
van RijkomHM, TruinGJ, van't HofMA. Caries-inhibiting effect of professional fluoride gel application in low-caries children initially aged 4.5-6.5 years. Caries Res 2004;38:115-123.
Weintraub JA, Ramos-Gomes F, Jue B, et al. Fluoride varnish efficacy in preventing Early Childhood Caries. J Dent Res 2006;85:172-176.
Zimmer S, Bizhang M, Seemann R, Witzke S, Roulet J-F. The effect of a preventive program, including the application of low-concentration fluoride varnish, on caries control in high-risk children. Clin Oral Invest 2001;5:40 44.
Dept. of Pediatric Dentistry, School of Dentistry, Faculty of Health Sciences, University of Aarhus, Aarhus, Denmark
Postal address: Prof. S. Poulsen. Department of Pediatric Dentistry, School of Dentistry, Faculty of Health Sciences, Aarhus University, Vennelyst Boulevard 9, DK-8000 Aarhus C, Denmark.
Table 1. Clinical characteristics of the three topical fluoride technologies reviewed in this working paper. Gels Long contact time, High fluoride concentrations, Long intervals between applications, Professional application and prescription from a dentist required. Mouthrinses Shorter contact time, Low fluoride concentrations, Short intervals between application, Can be implemented by auxiliary dental or non-dental personnel in non-clinical settings. Varnishes Long contact time, High fluoride concentrations, Applied in a clinical setting, and can be applied by auxiliary dental personnel. Table 2. Summary of controlled clinical trials on the effect of fluoride gels. Author Material and Intervention (Country) methods Jiang et al., 2005 612 children A: AFP foam (1.23%) (China) completing B: APF Gel (1.23%) Mean age: 6.5 yrs C: No treatment 2 yrs follow-up Double blind Madlena et al., 2002 410 children A: Elmex toothpaste (Hungary) completing daily + Elmex Gel Age: 14-16 yrs weekly 2 yrs follow-up B: Elmex toothpaste daily + placebo gel weekly C: "usual oral care habits" van Rijkom et al., 676 children A: Sodiumfluoride 2004 completing gel (1%) (The Netherlands) Age: 4.5-6.5 yrs B: Placebo gel 4 yrs follow-up Double blind Truin et al., 2005a Re-analysis of the same data as in van (The Netherlands) Rijkom, Truin, & van't Hof  with initial lesions included Truin et al., 2005b 516 children A: Sodiumfluoride (The Netherlands) Age: 9.5-11.5 yrs gel (1%) 4 yrs follow-up B: Placebo gel Double blind Truin at al., 2007 Re-analysis of the (The Netherlands) same data as in Truin & van't Hof [2005b] with initial lesions included Author Prevented Comments (Country) Fraction Jiang et al., 2005 A: vs. C 41% * Limited to smooth (China) B vs. C: 37% * surfaces on first permanent molars Madlena et al., 2002 A vs. B: 28% * (Hungary) van Rijkom et al., A vs. B: 26% * One-sided t-test; 2004 no effect in (The Netherlands) primary dentition Study limited to dentinal lesions Authors' conclusion: "not clinically relevant" Truin et al., 2005a A vs. B: 22% * Authors conclusion (The Netherlands) the same as in van Rijkom, Truin, & van't Hof  Truin et al., 2005b A vs. B: 18% Study limited to (The Netherlands) dentinal lesions Truin at al., 2007 A vs. B: 23% * (The Netherlands) * : P [less than or equal to] 0.05 Table 3. Summary of a controlled clinical trial on the effect of fluoride mouth rinses Author Material and Intervention (Country) methods Skold et al., 2005a 622 children Rising with 0.2% (Sweden) completing sodium fluoride Age: 13-16 yrs 3 yrs follow-up A: First three schooldays each semester B: First and last three schooldays each semester C: Three consecutive days once a month D: Twice every fortnight E: No rinses Author Prevented Comments (Country) Fraction Skold et al., 2005a A vs. E: 30% Limited to (Sweden) radiographic B vs. E: 59% * diagnosis of approximal surfaces C vs. E: 47% * D vs. E: 41% * *: P [less than or equal to] 0.05 Table 4. Summary of controlled clinical trials on the effect of fluoride varnishes. Author Material and Intervention (Country) methods Borutta et al., 200 children Six-monthly 2006 (Germany) completing applications of two different brands of Age: 2-4 yrs varnish (A and B), both with 5% sodium 2 yrs follow-up fluoride. C: No varnish Bravo et al., 2005 120 children A: Fissure sealant (Spain) completing B: 5% sodium Age: 7.6 yrs fluoride varnish every 6th month the 4 yrs follow-up first four years C: No intervention Hardman et al., Limited to occlusal A: 5% sodium 2007 (England) surfaces fluoride varnish every 6th month B: No intervention Skold et al., 2005b 758 children 5% sodium fluoride (Sweden) completing varnish Age: 13-16 yrs A: twice a year 3 yrs follow-up B: three times a year within one week C: eight times a year D: No treatment Weintraub et al., 280 children 5% sodium fluoride 2006 (USA) completing varnish Mean age: 1.8 yrs A: once a year 2 yrs follow-up B: twice a year C: No treatment Zimmer et al., 2001 318 children A: 0.1% fluoride (Germany) completing varnish Mean age: 9.55 yrs B: No intervention 2 yrs follow-up Author Prevented Comments (Country) Fraction Borutta et al., A vs. C: 56% * dmfs 2006 (Germany) B vs. C: 57% * Bravo et al., 2005 B vs. C: 34% * Limited to occlusal (Spain) surfaces Hardman et al., A vs. B at No statistical 2007 (England) d1fs level: significant 48% * difference at d2fs and d3fs level; no statistical significant difference in permanent teeth Skold et al., 2005b A vs. D: 57% * Limited to (Sweden) radiographic B vs. D: 47% * diagnosis of approximal surfaces C vs. D: 76% * Weintraub et al., A vs. B: 58% * D2+fs 2006 (USA) B vs. C: 61% * Zimmer et al., 2001 A vs. B: 40% * No increment No (Germany) at D1-2S- statistical level significant difference at D3.4S-level *: P [less than or equal to] 0.05
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|Publication:||European Archives of Paediatric Dentistry|
|Date:||Sep 1, 2009|
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