Color matching between orthodontic attachments and tooth structure using monoshade composites: An instrumental...

Monoshade resin composites were developed to simplify restorative procedures by eliminating the need for shade selection. Although their performance in the restoration of cavities is well established, their effectiveness in color matching when used for the fabrication of orthodontic attachments remains uncertain.

Forty extracted human molars were randomly assigned to 4 groups (n = 10): Omnichroma (Tokuyama Dental, Tokyo, Japan), Vittra Unique (FGM, Joinville, Brazil), Charisma Diamond ONE (Kulzer GmbH, Hanau, Germany), and Vittra APS Trans-N (FGM) (control). Standardized attachments were fabricated using silicone molds, and color was assessed via standardized digital photography. After white balance correction, CIEL∗a∗b∗ color coordinates were measured for both the resin and adjacent enamel in 3 regions (cervical, middle, and occlusal). Color differences were calculated using the CIEDE2000 formula (ΔE₀₀).

Color differences presented statistically significant differences among the tested regions for all composite resins (P <0.001). In the occlusal region, ΔE₀₀ values were within acceptable or moderately unacceptable thresholds. In the cervical region, all materials showed clearly or extremely unacceptable ΔE₀₀ values. In the middle third, statistically significant differences were found among the resin composites for ΔE₀₀ (P <0.001), ΔL∗ (P = 0.002), Δa∗ (P <0.001), and Δb∗(P <0.001).

Color matching of orthodontic attachments fabricated with monoshade composites varied according to the resin composite used and the anatomic region. The occlusal region demonstrated improved color match, whereas the cervical region showed reduced color compatibility between the attachment and the tooth structure.