Fluoride-Containing Materials and the Prevention of Demineralization During Orthodontic Treatment—Which Research Method Should We Now Use?

Efficacy of sealants and bonding materials during fixed orthodontic treatment to prevent enamel demineralization: a systematic review and meta-analysis

To analyse clinical studies investigating coating agents such as sealants and other bonding materials to prevent the initiation or inhibit the progress of white spot lesions (WSL) during orthodontic treatment with fixed appliances. Electronic databases (Pubmed, CENTRAL, EMBASE) were screened for studies. No language restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Primary outcome included assessment of WSL with visual-tactile assessment and/or laser fluorescence measurements. Twenty-four studies with 1117 patients (age: 11–40 years) and 12,809 teeth were included. Overall, 34 different sealants or bonding materials were analysed. Fourteen studies analysed fluoride and 14 studies non-fluoride releasing materials. Meta-analysis for visual tactile assessment revealed that sealants significantly decreased the initiation of WSL compared to untreated control (RR [95%CI] = 0.70 [0.53; 0.93]; very low level of evidence). Materials releasing fluoride did not decrease initiation of WSL compared to those with no fluoride release (RR [95%CI] = 0.84 [0.70; 1.01]; very low level of evidence). For laser fluorescence measurements no meta-analysis could be performed. The use of sealants seems to be effective in preventing the initiation of post-orthodontic WSL. Furthermore, there is no evidence supporting that fluoride-releasing sealants or bonding materials are more effective than those without fluoride release. No gold standard prevention strategy to prevent WSL during treatment with fixed orthodontic appliances has been established yet. However, based on only a limited number of studies the use of sealants seems to be effective in preventing the initiation of post-orthodontic WSL.

Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment

BACKGROUND

Early dental decay or demineralised lesions (DLs, also known as white spot lesions) can appear on teeth during fixed orthodontic (brace) treatment. Fluoride reduces decay in susceptible individuals, including orthodontic patients. This review compared various forms of topical fluoride to prevent the development of DLs during orthodontic treatment. This is the second update of the Cochrane Review first published in 2004 and previously updated in 2013.

OBJECTIVES

The primary objective was to evaluate whether topical fluoride reduces the proportion of orthodontic patients with new DLs after fixed appliances. The secondary objectives were to examine the effectiveness of different modes of topical fluoride delivery in reducing the proportions of orthodontic patients with new DLs, as well as the severity of lesions, in terms of number, size and colour. Participant-assessed outcomes, such as perception of DLs, and oral health-related quality of life data were to be included, as would reports of adverse effects.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 1 February 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1) in the Cochrane Library (searched 1 February 2019), MEDLINE Ovid (1946 to 1 February 2019), and Embase Ovid (1980 to 1 February 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Parallel-group, randomised controlled trials comparing the use of a fluoride-containing product versus a placebo, no treatment or a different type of fluoride treatment, in which 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. Cochrane's statistical guidelines were followed.

MAIN RESULTS

This update includes 10 studies and contains data from nine studies, comparing eight interventions, involving 1798 randomised participants (1580 analysed). One report contained insufficient information and the authors have been contacted. We assessed two studies as at low risk of bias, six at unclear risk of bias, and two at high risk of bias. Two placebo (non-fluoride) controlled studies, at low risk of bias, investigated the professional application of varnish (7700 or 10,000 parts per million (ppm) fluoride (F)), every six weeks and found insufficient evidence of a difference regarding its effectiveness in preventing new DLs (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.14 to 1.93; 405 participants; low-certainty evidence). One placebo (non-fluoride) controlled study, at unclear risk of bias, provides a low level of certainty that fluoride foam (12,300 ppm F), professionally applied every two months, may reduce the incidence of new DLs (12% versus 49%) after fixed orthodontic treatment (RR 0.26, 95% CI 0.11 to 0.57; 95 participants). One study, at unclear risk of bias, also provides a low level of certainty that use of a high-concentration fluoride toothpaste (5000 ppm F) by patients may reduce the incidence of new DLs (18% versus 27%) compared with a conventional fluoride toothpaste (1450 ppm F) (RR 0.68, 95% CI 0.46 to 1.00; 380 participants). There was no evidence for a difference in the proportions of orthodontic patients with new DLs on the teeth after treatment with fixed orthodontic appliances for the following comparisons: - an amine fluoride and stannous fluoride toothpaste/mouthrinse combination versus a sodium fluoride toothpaste/mouthrinse, - an amine fluoride gel versus a non-fluoride placebo applied by participants at home once a week and by professional application every three months, - resin-modified glass ionomer cement versus light-cured composite resin for bonding orthodontic brackets, - a 250 ppm F mouthrinse versus 0 ppm F placebo mouthrinse, - the use of an intraoral fluoride-releasing glass bead device attached to the brace versus a daily fluoride mouthrinse. The last two comparisons involved studies that were assessed at high risk of bias, because a substantial number of participants were lost to follow-up. Unfortunately, although the internal validity and hence the quality of the studies has improved since the first version of the review, they have compared different interventions; therefore, the findings are only considered to provide low level of certainty, because none has been replicated by follow-up studies, in different settings, to confirm external validity. A patient-reported outcome, such as concern about the aesthetics of any DLs, was still not included as an outcome in any study. Reports of adverse effects from topical fluoride applications were rare and unlikely to be significant. One study involving fluoride-containing glass beads reported numerous breakages.

AUTHORS' CONCLUSIONS

This review found a low level of certainty that 12,300 ppm F foam applied by a professional every 6 to 8 weeks throughout fixed orthodontic treatment, might be effective in reducing the proportion of orthodontic patients with new DLs. In addition, there is a low level of certainty that the patient use of a high fluoride toothpaste (5000 ppm F) throughout orthodontic treatment, might be more effective than a conventional fluoride toothpaste. These two comparisons were based on single studies. There was insufficient evidence of a difference regarding the professional application of fluoride varnish (7700 or 10,000 ppm F). Further adequately powered, randomised controlled trials are required to increase the certainty of these findings and to determine the best means of preventing DLs in patients undergoing fixed orthodontic treatment. The most accurate means of assessing adherence with the use of fluoride products by patients and any possible adverse effects also need to be considered. Future studies should follow up participants beyond the end of orthodontic treatment to determine the effect of DLs on patient satisfaction with treatment.

Effectiveness of an antibacterial primer used with adhesive-coated brackets on enamel demineralization around brackets: an in vivo study

Background

The aim of the study is to assess the clinical effect of an antibacterial monomer-containing primer on preventing white spot lesions (WSLs) during fixed orthodontic treatment.

Subject and methods

The study included 35 patients. A split-mouth design was used during bonding of the brackets. In Clearfil (CF) group, adhesive-coated brackets (APC Plus Victory series, 3M Unitek, Monrovia, CA, USA) were bonded with an antibacterial monomer-containing primer (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan). In Transbond (TB) group, the same adhesive-coated brackets were bonded using a conventional primer (Transbond XT Primer; 3M Unitek, Monrovia, CA, USA). The mean duration of orthodontic treatment was 16 months. Digital images of each tooth were used to assess the WSLs. The areas of the WSLs were measured with a software. The bond failures during orthodontic treatment were also recorded.

Results

After fixed orthodontic treatment, 23 of the 35 patients showed one or more WSLs. Of the total of 666 teeth, 114 WSLs occurred over the orthodontic treatment time. Rates of WSL in the CF and TB groups were 8.03% and 9.24%, respectively. The difference in WSL rates between the two groups was not statistically significant. No significant difference was observed in the lesion areas between the groups. Moreover, the difference in bracket failure rates between the two groups was also not statistically significant.

Conclusion

The results of this long-term clinical study indicated no significant difference between the antibacterial monomer-containing primer group and the control group in the efficacy of reducing demineralization throughout the orthodontic treatment.

In vivo effect of antibacterial and fluoride-releasing adhesives on enamel demineralization around brackets: A micro-CT study

OBJECTIVES

The aim of this in vivo study was to investigate the preventive effect of two different adhesives on enamel demineralization and compare these adhesives with a conventional one.

MATERIALS AND METHODS

Fifteen patients requiring the extraction of their first four premolars for orthodontic treatment were included in the study. One premolar was randomly selected, and an antibacterial monomer-containing and fluoride-releasing adhesive (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan) was used for orthodontic bracket bonding. Another premolar was randomly selected, and a fluoride-releasing and recharging orthodontic adhesive (Opal Seal, Ultradent Products, South Jordan, Utah) was used. One premolar was assigned as a control, and a conventional adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was used. The teeth were extracted after 8 weeks, and the demineralization areas of the 45 extracted teeth were analyzed using microcomputed tomography with software.

RESULTS

There was no significant difference between the white spot lesion (WSL) rates of the adhesives (P > .05). The volumes of the WSLs varied from 0 to 0.019349 mm³. Although Opal Seal showed the smallest lesion volumes, there was no significant difference in volumetric measurements of the lesions among the groups (P > .05).

CONCLUSIONS

The findings indicated no significant differences between the preventive effects of the adhesives used in this in vivo study over 8 weeks.

Effects of different orthodontic primers on enamel demineralization around orthodontic brackets

AIM

The purpose of this work is to evaluate the effectiveness of one self-etching and two filled orthodontic primers on enamel demineralization around orthodontic brackets.

METHODS

Brackets were bonded to 84 bovine teeth and the vestibular enamel surfaces covered with acid-resistant nail varnish exposing 1 mm of space on each side of the bracket base. The teeth were allocated to four groups, using either Transbond XT conventional primer on etched enamel (group 1), Transbond Plus Self-Etching Primer on untreated enamel (group 2), Pro Seal filled resin primer on etched enamel (group 3), or Opal Seal filled resin primer on etched enamel (group 4). Each tooth was subjected to 15,000 strokes of brushing followed by exposure to an acid challenge. Calcium-ion release from each sample was calculated using atomic absorption spectrophotometry. Data were analyzed using one-way ANOVA and a post hoc Tukey test. Differences were considered statistically significant at p ≤ 0.05.

RESULTS

Statistically significant differences were observed between the four groups (p < 0.001). No significant difference was found between the controls (group 1) and the Opal Seal group. Higher calcium release was observed in the Pro Seal group and the self-etching primer group compared to the controls. The highest calcium release was recorded in the self-etching primer group.

CONCLUSION

Filled sealants may not have a protective effect against enamel demineralization. Transbond Plus Self-Etching Primer should be used cautiously, considering the risk of demineralization involved in its application.

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

BACKGROUND

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.

OBJECTIVES

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 METHODS

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.

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.