Color evaluation of a one-shade used for restoration of non-carious cervical lesions: an equivalence randomized clinical trial.

Background: Obtaining a perfect color match with resin composite presents a significant challenge. The chameleon effect has enabled resin composite to mimic the color of the adjacent tooth structure in vitro. This double-blind, split-mouth and equivalent randomized clinical trial evaluated the color matching of one-shade resin composite with chameleon effect versus multi-shade resin composite in non-carious cervical lesion restorations (NCCLs). Methods: One hundred twenty restorations were performed on NCCLs with two restorative materials (n = 60). After prophylaxis, the teeth were isolated with rubber dam and one universal adhesive was applied in the selective enamel etching strategy. For both groups, the restorations were inserted incrementally. The values of ΔE_ab and ΔE₀₀ in the cervical and middle third were evaluated using a digital spectrophotometer before vs. after the restorations. The restorations were evaluated at baseline and after 7 days, 6-, 12- and 18-month of clinical performance according to the FDI criteria (Word Federation Criteria). Statistical analysis was performed using Chi-square test for all parameters. Color change was analyzed by two one-sided t-tests for paired samples (α = 0.05). Results: Regarding the color measurement no significant difference was observed when Vittra APS (FGM Dental Products, Joinville, SC, Brazil) was compared to Vittra Unique (FGM Dental Products, Joinville, SC, Brazil) for any of the comparisons performed (p > 0.05). However, the ΔE_ab and ΔE₀₀ values for the cervical third, both before and after the restorations, were higher compared to the ΔE_ab and ΔE₀₀ values observed when comparing the cervical and middle thirds after the restorations. After 18 months, five restorations exhibited minimal discrepancies in terms of marginal adaptation or marginal discoloration (p > 0.05). In all other criteria, including retention rate, no changes were detected at the 18-month recall. Conclusions: The one-shade resin composite used achieve the same color match when compared to a multi-shade resin composite after a period of 7 days in NCCLs. Overall, the restorations scored clinically very good (FDI) at baseline and after 18 months for all outcomes. Clinical Significance: The use of a one-shade resin composite in NCCLs can be recommended because it has the ability to simplify the restoration procedure and maintaining an excellent clinical performance. Registration of clinical trials: RBR-8txr4fw: 26/05/2022. [ABSTRACT FROM AUTHOR]