In-vitro investigation of the effects of remineralization agents and different treatment techniques on the color of teeth with white spot lesions after orthodontic bonding

The aim of this in-vitro study was to compare the effects of resin infiltration, microabrasion, bleaching and different remineralization agents on color changes of white spot lesions. 135 lower and upper 1. and 2. premolar teeth which were extracted for orthodontic treatment were used. The teeth were embedded in acrylic resin except their crowns and initial color values (T0) were measured with Vita Easyshade Advance 4.0. The teeth were subjected to demineralization-remineralization cycle for 21 days after bonding of the brackets to form white spots. After debonding, second color values (T1) were measured. Teeth were randomly divided into 9 equal groups that were; control, Elmex, Enamelon, Biflorid-Parodontax, casein phosphopeptide-amorphous calcium phosphate (CPP- ACP), resin infiltration, bleaching, bleaching- resin infiltration and microabrasion. After the applications, third color measurements (T2) were done. ΔE and L* values were analyzed using Friedman test and repeated measures ANOVA for intragroup comparison and Kruskal-Wallis test and one way ANOVA for intergroup comparison. While similar color changes were observed between initial measurement-demineralization (ΔE1) interval in all groups, different agents resulted in different levels of color change (ΔE2) in white spots. Applications that caused the highest color changes were found to be microabrasion, bleaching- resin infiltration, bleaching and resin infiltration, respectively. Effect of remineralization of the lesions by saliva without any application to tooth surfaces was similar to the effects of Biflorid-Parodontax, Elmex, Enamelon and CPP-ACP applications on tooth color. Microabrasion, bleaching-resin infiltration, bleaching and resin infiltration techniques are successful in masking white spot lesions quickly and effectively after orthodontic treatment. Since the other tested applications which were less effective in masking the white spots have similar effects on tooth color as the control group, remineralization of the teeth by saliva may be preferable instead of these applications. Keywords: Color, Demineralization, Remineralization, White spot lesion.