Two-year clinical evaluation of proanthocyanidins added to a two-step etch-and-rinse adhesive

Objective: To compare the clinical behavior of Proanthocyanidins (PA)-free and PA-containing two-step etch-and-rinse adhesive used underneath resin composite restorations in non-carious cervical lesions (NCCLs) over a 6-(6 M) and 24-month (24 M) period. Methods: 135 restorations were randomly placed in 45 subjects. The NCCLs were conditioned (37% phosphoric acid for 15 s) and distributed into 3 groups: Control (EX0) - ExciTE F (Ivoclar Vivadent) adhesive applied following the manufacturer's recommendations; EX2 and EX5 - 2 wt% and 5 wt% of PA were added to ExciTE F, respectively, and applied as in EX0. Resin composite was placed incrementally and light-cured. The restorations were evaluated at baseline, 6M and 24 M, using FDI and USPHS criteria. Statistical analyses were performed using Friedman and Wilcoxon tests (alpha = 0.05). Results: The retention rates were 98% (95% confidence interval 88-99%) for EX0, 92% (80-97%) for EX2; and 85% (72-93%) for EX5 at 6 M. A significant difference was found only for EX5 at 6M when compared with the respective baseline findings (p = 0.03) and when compared with EX0 and EX2 (p = 0.001) at 6M. After 24 M, the retention rates were 98% (88-99%) for EX0, 73% (59-84%) for EX2, and 71% (56-82%) for EX5. Only EX0 did not result in significant difference in retention rate at 24M when compared with baseline but showed a significant higher retention rate when compared with those of EX2 and EX5 (p = 0.001). Conclusion: Adding proanthocyanidins to the adhesive solution jeopardized the retention of composite resins restorations in non-carious cervical lesions after 24 months.