Objective: The study attempted to assess the effect of application of four natural matrix metalloproteinases inhibitors (proanthocyanidin, quercetin, chlorogenic acid and hesperidin); as dentin pre-treatment agents; on the shear bond strength of Vertise Flow self adhesive flowable composite to dentin.
Materials and methods: The study included five groups: Group I (control): Dentin was etched and the composite was applied without pre-treatment. Group II: Etched dentin was pre-treated with 2% proanthocyanidin prior to composite application. Group III: 2% quercetin solution was used. Group IV: 2 % chlorogenic acid was used. Group V: 2 % hesperidin solution was used.
Shear bond strength of 40 specimens in each group was measured; 20 specimens were tested at 24 hours, and other 20 specimens were tested after thermocycling.
Failure mode was analyzed according to Adhesive Remnant Index scoring system.
Scanning electron microscopic imaging for the composite/ dentin adhesive junction was performed.
Results: Shear bond strength testing after thermocycling revealed that group II recorded the highest value among all groups, whereas group IV recorded the least value.
Concerning the failure mode; the majority of specimens of groups I and IV recorded score (1). Concerning groups II, III and V, the majority of specimens registered score (2). Conclusions: Proanthocyanidin can be considered a highly potent matrix metalloproteinases inhibitor to enhance and promote a satisfactory bonding stability of flowable composite to dentin, followed by quercetin and hesperidin. However, application of chlorogenic acid is not recommended.