effects of orthodontic adhesives on dental enamel color alteration using chemically cured and light-cured composites

Objectives: the purpose of this investigation was to evaluate the color alteration of dental enamel following the use of light-cured and chemically cured composites for bonding of metal brackets. materials and methods: sixty extracted human premolars divided into five groups (n=12) were included in this study. metal brackets were bonded using chemically cured (system 1+ and unite) and light-cured (transbond xt and grengloo) composites. the control group remained untreated. after 72 hours of immersion in a staining solution and 24 hours of photoaging, the brackets were debonded, and adhesive remnants were cleaned using a 12-blade tungsten carbide bur and polished with sof-lex discs. the color was assessed at the baseline and after cleaning procedures in accordance with the cie l*a*b (lightness, red/green, blue/yellow) color system. statistical analyses were performed using paired sample t-test and one-way analysis of variance (anova). results: the l*, a*, and b* parameters showed a significant increase in all adhesive groups (p<0.001). the experimental groups showed significant color changes (p<0.05), and the mean δe ranged from 2.46 to 3.15 units. no significant difference was found between the δe of the adhesive groups (p>0.05). conclusion: the enamel color change is influenced by bonding and debonding procedures. chemically cured and light-cured composites have similar effects on dental enamel color alterations.