ORIGINAL ARTICLE Effect of high-fluoride dentifrice and bracket bonding composite material on enamel demineralization in situ Robson S. Ferreira 1,2 & Antonio Pedro Ricomini-Filho 2 & Cínthia P. Tabchoury 2 & Glauber Campos Vale 1,3 Received: 26 March 2019 /Accepted: 20 December 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Objective This in situ study evaluated the effect of high-fluoride dentifrice (5000 μgF - /g) and fluoride-containing bonding composite resin on enamel demineralization adjacent to orthodontic brackets. Methods Ten volunteers wore palatal appliances containing bovine enamel blocks with metallic brackets bonded with fluoride- free or fluoride-containing composite resin. During three phases of 14 days each, three dentifrices with different fluoride concentrations (0, 1100, and 5000 μgF - /g) were tested. The cariogenic challenge consisted of 20% sucrose solution dripped 8x/day onto the dental blocks. At the end of each phase, biofilm formed was collected for fluoride analysis. Cross section hardness was performed in enamel blocks, and the lesion area was calculated. Data were analyzed by two-way ANOVA followed by Tukey post hoc test (α = 5%). Results The only signicant factor for all the variables under study was the dentifrice. Smaller lesion area and higher fluoride concentration on biofilm were found in 5000 μgF - /g group, irrespective of bonding composite resin (p < 0.001). Neither bracket- bonding composite resin nor the interaction between the factors was statistically significant (p > 0.05) for all the variables. Conclusion High-fluoride dentifrice is effective in reducing demineralization on enamel adjacent to orthodontic brackets, while the fluoride-containing bonding composite resin does not influence it. Clinical Significance Since high-fluoride dentifrice was able to reduce demineralization adjacent to brackets, it can be an option to caries management in orthodontics patients. Keywords Bonding materials . Orthodontic brackets . Dentifrices . Enamel demineralization Introduction Orthodontic patients are considered to be at high risk for white spot lesions development [1], which are clinical signs of dental caries in enamel and may be commonly observed ad- jacent to orthodontic brackets [2]. Orthodontic appliances (re- tention factor for dental biofilm accumulation) together with poor oral hygiene lead to the development of these lesions. In addition, the long term of treatment favors the appearance of more lesions [3]. Therefore, preventive measures are recommended to re- duce demineralization adjacent to orthodontic brackets, such as diet control, regular professional prophylaxis, use of fluo- ride (F - ) mouthrinse and varnish [4], F - antiplaque dentifrice [5], and high-fluoride dentifrice [6, 7]. Bracket-bonding ma- terials with the premise of F - -releasing have also been recom- mended, but there is little evidence of their effectiveness [8, 9], and the effect of its association with F - dentifrice has not been adequately elucidated yet. Regarding professional F - applications, F - -varnishes are clinically effective in preventing white spots lesions in ortho- dontic patients with applications every 6 weeks [10] compared to a single initial application [ 11]. On the other hand, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00784-019-03182-7) contains supplementary material, which is available to authorized users. * Glauber Campos Vale glauber@ufpi.edu.br 1 Restorative Dentistry Department, Federal University of Piauí, Teresina, Piauí, Brazil 2 Physiological Sciences Department, Piracicaba Dental School, Piracicaba, Brazil 3 Restorative Dentistry Department, Campus Universitário Ministro Petrônio Portella – SG 10, Bairro Ininga, Teresina, Piauí CEP: 64049-550, Brazil Clinical Oral Investigations https://doi.org/10.1007/s00784-019-03182-7