Effects of staining solutions on the discoloration of orthodontic adhesives: an in-vitro study

Our aim was to evaluate the effects of staining solutions on the discoloration of orthodontic adhesives.

Six orthodontic adhesives were investigated (Transbond XT [3M Unitek, Monrovia, Calif, USA], Heliosit Orthodontic [Ivoclar Vivadent, Liectenstein], Light Bond [Reliance Orthodontic Products, Itasca, IL, USA], Bisco Ortho [Bisco, Schamburg, IL, USA], Quick Cure [Reliance Orthodontic Products, Itasca, IL, USA], and Filtek Supreme XT [3M ESPE, St Paul, Minn, USA]), and 5 beverages (tea, cola, coffee, red wine, and yogurt). Sixty specimens were prepared. Five specimens from each group were stored in each of the 5 staining solutions. The 5 remaining specimens from each group served as the controls and were stored in distilled water. The specimens were immersed in staining solutions and water at 37°C ± 1°C for 5 days. The test period was 25 days. Before and after the test period, color measurements were carried out with a spectrophotometer, and color changes (ΔE∗) were calculated. Statistical differences were evaluated by using analysis of variance (ANOVA) and the Tukey HSD tests.

Adhesive materials, staining agents, and their interactions were found to play statistically significant roles (P < 0.001) in color changes. Among the adhesive materials, the Light Bond water control group consistently showed the lowest ΔE∗ value for all materials, and the Filtek Supreme XT group showed the highest ΔE∗ value for all materials. After the in-vitro experimental process for staining solutions and water, unsatisfactory color stability was observed for the conventional adhesive systems except for Light Bond, Transbond XT, and Bisco Ortho water control group (ΔE∗ > 3.7), respectively.

In esthetically critical areas, discoloration of adhesive materials for fixed orthodontics can cause patient dissatisfaction. Orthodontic composites will discolor from staining beverages during their lifespan.