INFLUENCE OF DENTIN COLLAGEN BIOMODIFICATION USING PROANTHOCYANIDIN, RIBOFLAVIN/UV PHOTOCROSSLINKING, AND CARBODIIMIDE ON THE AGED MICROTENSILE BOND STRENGTH OF SELF-ADHESIVE RESIN CEMENTS

Abstract

Background: Degradation of the resin–dentin interface remains a major challenge affecting the longevity of adhesive restorations. Dentin collagen biomodification using cross-linking agents has been proposed as a strategy to enhance collagen stability and improve long-term bond durability.

Aim: To evaluate the influence of dentin collagen biomodification using proanthocyanidin, riboflavin/UV photo cross linking, and carbodiimide on the aged microtensile bond strength of self-adhesive resin cements.

Materials and Methods: A total of 100 extracted human permanent molars were randomly allocated into five groups (n=20): Control, Proanthocyanidin, Riboflavin/UV Photocrosslinking, Carbodiimide, and Combined Biomodification. Following dentin pretreatment, composite resin blocks were cemented using a self-adhesive resin cement. Each group was further subdivided into immediate and aged subgroups (n=10). Aging was performed using 10,000 thermocycles and six months of water storage. Microtensile bond strength testing was conducted using a universal testing machine, and failure modes were evaluated under stereomicroscopy. Statistical analysis was performed using one-way ANOVA and Student’s t-test with a significance level of p<0.05.

Results: Significant differences in microtensile bond strength were observed among the groups (p<0.001). The Combined Biomodification Group demonstrated the highest immediate (33.14 ± 2.48 MPa) and aged (30.52 ± 2.29 MPa) bond strength values, followed by the Proanthocyanidin, Carbodiimide, and Riboflavin/UV groups. The Control Group exhibited the lowest bond strength and the greatest reduction after aging. Biomodification groups showed significantly improved bond durability and a higher frequency of mixed failures compared with the control group.

Conclusion: Dentin collagen biomodification significantly enhanced the aged microtensile bond strength of self-adhesive resin cements. The combined use of proanthocyanidin and carbodiimide provided the greatest improvement in bond durability and resistance to degradation. Biomodification strategies may represent an effective approach for improving the longevity of resin–dentin bonds and adhesive restorations.