In vitro caries-preventive effect of fluoridated orthodontic resins against cariogenic challenge stimulation

The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. Brackets were bonded to 120 extracted human premolars, using Rely-a-bond (n = 40), Tru- Bond (n = 40) and Ortho-one (n = 40) orthodontic bonding agents. Each group of resin was divided into 2 subgroups (n = 20): immersion in remineralizing artificial saliva for 14 days and acid saliva with pH 4.3. After 14 days of pH cycling the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0 = absence and 1 = presence. Kruskal-Wallis ANOVA and Mann-Whitney U tests were used. Formation of white spot lesions was observed only under pH cycling using acid saliva with pH 4.3; with Rely-a-bond and Tru-Bond being significantly more effective in preventing the appearance of white spot lesions effect than Ortho-one. The acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. Rely-a-bond and Tru-bond presented higher caries-preventive effect than Orthoone. The development of fluoride-containing materials cannot be regarded as a permanent means to control dental caries lesions, but a complement along with other preventive methods.