Fluorides for the prevention of early tooth decay (demineralised white lesions) during fixed brace treatment

Review question

Ugly white marks sometimes appear on the teeth during orthodontic (brace) treatment. These are caused by early tooth decay and usually occur with fixed (or glued-on 'train track') braces when the teeth are not cleaned properly.

We know that fluoride in toothpaste helps to prevent dental decay; therefore, extra fluoride provided to people wearing braces should protect them from these marks. This review, produced by the Cochrane Oral Health Group, examines the evidence for this in existing research. The aim of this review is to assess the effectiveness of fluorides in preventing early tooth decay during orthodontic (brace) treatment and to determine the best way to do this.


Early tooth decay around the brackets that attach braces to the teeth can cause white or brown marks (demineralised white lesions (DWLs)) to appear on teeth during fixed brace treatment. Build-up of dental plaque around these brackets is associated with increased risk of rapid demineralisation of the enamel of teeth. Demineralisation is an early, but reversible, stage in the development of tooth decay. Wearing of fixed braces may be associated with pain, and both the brace and the pain make toothbrushing more difficult, which in turn means that it is harder to prevent the build-up of plaque. People often wear braces for 18 months or longer, and there is a risk that tooth decay will damage the teeth, requiring restorations and fillings to be done.

Fluoride is effective in reducing tooth decay in people who are at risk of developing it. Individuals receiving orthodontic treatment may be prescribed various forms of fluoride treatment. It is important to consider how the fluoride is to be applied and whether children and adolescents (receiving fixed brace treatment) are likely to be willing and able to regularly apply by themselves the amounts needed to prevent early tooth decay.

Study characteristics

The evidence on which this review is based was up-to-date as of 31 January 2013. Three studies with 458 participants were included in this updated review. Participants were undergoing orthodontic treatment with fixed braces, and DWLs were assessed on teeth remaining in the mouth at the end of orthodontic treatment.

The different ways of applying fluoride that were assessed included:

1. topical fluorides, for example, fluoride-containing varnish, mouthrinse, gel or toothpaste;
2. fluoride-releasing devices attached to the braces; and
3. control group approaches - individuals did not receive additional fluoride as described, or they received a placebo or a different form of fluoride.

Key results

One study showed that when the dentist paints fluoride-containing varnish around the teeth and brace every time it is adjusted, the risk of developing white marks is reduced by nearly 70%; however, further well-designed trials are required to confirm this finding.

The rest of the evidence is weak, and more studies are needed to show the best way of delivering extra fluoride to people wearing braces. Adverse effects or harms of interventions were not reported in any of the included studies.

Quality of the evidence

The quality of the evidence found is moderate in the case of one well-designed study and weak in the remaining studies. Recommendations state that further well-conducted research should be conducted in this area.

Authors' conclusions: 

This review found some moderate evidence that fluoride varnish applied every six weeks at the time of orthodontic review during treatment is effective, but this finding is based on a single study. Further adequately powered, double-blind, randomised controlled trials are required to determine the best means of preventing DWLs in patients undergoing orthodontic treatment and the most accurate means of assessing compliance with treatment and possible adverse effects. Future studies should follow up participants beyond the end of orthodontic treatment to determine the effect of DWLs on participant satisfaction with treatment.

Read the full abstract...

Demineralised white lesions (DWLs) can appear on teeth during fixed brace treatment because of early decay around the brackets that attach the braces to the teeth. Fluoride is effective in reducing decay in susceptible individuals in the general population. Individuals receiving orthodontic treatment may be prescribed various forms of fluoride treatment. This review compares the effects of various forms of fluoride used during orthodontic treatment on the development of DWLs. This is an update of a Cochrane review first published in 2004.


The primary objective of this review was to evaluate the effects of fluoride in reducing the incidence of DWLs on the teeth during orthodontic treatment.

The secondary objectives were to examine the effectiveness of different modes of fluoride delivery in reducing the incidence of DWLs, as well as the size of lesions. Participant-assessed outcomes, such as perception of DWLs, and oral health–related quality of life data were to be included, as would reports of adverse effects.

Search strategy: 

We searched the Cochrane Oral Health Group's Trials Register (to 31 January 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12); MEDLINE via OVID (1946 to 31 January 2013); and EMBASE via OVID (1980 to 31 January 2013).

Selection criteria: 

We included trials if they met the following criteria: (1) parallel-group randomised clinical trials comparing the use of a fluoride-containing product versus placebo, no treatment or a different type of fluoride treatment, in which (2) the outcome of enamel demineralisation was assessed at the start and at the end of orthodontic treatment.

Data collection and analysis: 

At least two review authors independently, in duplicate, conducted risk of bias assessments and extracted data. Authors of trials were contacted to obtain missing data or to ask for clarification of aspects of trial methodology. The Cochrane Collaboration's statistical guidelines were followed.

Main results: 

For the 2013 update of this review, three changes were made to the protocol regarding inclusion criteria. Fourteen studies included in the previous version of the review were excluded from this update for the following reasons: five previously included studies were quasi-randomised, a further five were split-mouth studies, three measured outcomes on extracted teeth only and in one, the same fluoride intervention was used in each intervention group of the study.

Three studies and 458 participants were included in this updated review. One study was assessed at low risk of bias for all domains, in one study the risk of bias was unclear and in the remaining study, the risk of bias was high.

One placebo-controlled study of fluoride varnish applied every six weeks (253 participants, low risk of bias), provided moderate-quality evidence of an almost 70% reduction in DWLs (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.21 to 0.44, P value < 0.001). This finding is considered to provide moderate-quality evidence for this intervention because it has not yet been replicated by further studies in orthodontic participants.

One study compared two different formulations of fluoride toothpaste and mouthrinse prescribed for participants undergoing orthodontic treatment (97 participants, unclear risk of bias) and found no difference between an amine fluoride and stannous fluoride toothpaste/mouthrinse combination and a sodium fluoride toothpaste/mouthrinse combination for the outcomes of white spot index, visible plaque index and gingival bleeding index.

One small study (37 participants) compared the use of an intraoral fluoride-releasing glass bead device attached to the brace versus a daily fluoride mouthrinse. The study was assessed at high risk of bias because a substantial number of participants were lost to follow-up, and compliance with use of the mouthrinse was not measured.

Neither secondary outcomes of this review nor adverse effects of interventions were reported in any of the included studies.