In Vitro Study Evaluating the Effect of Proanthocyanidin Pre-treatment Protocols on resin/dentin Bond Strength and Composite Resin Color stability

Abstract

Our study aimed to investigate the effect of two concentrations of proanthocyanidin ( with different application techniques on the micro-tensile bond strength of the dental adhesive to dentin in two-time intervals. Also, to investigate the effects of these applications on the color stability of resin composite in two-time intervals. According to the literature, hydrolytic and enzymatic degradation occurs overtime at the resin dentin interface. These degradations might be the reason for decreased bond durability. Proanthocyanidin, a natural cross collagen linker, was applied to dentin in a concentration of 6.5%w/v and 10%w/v for 1min (clinically relevant time), then washed or left with no wash. It was applied in the form of PA adhesive pre-conditioner. Micro-tensile bond strength testing of the dental adhesive in the different pretreatment modalities was measured in comparison with the control group. µTBS bond strength testing was performed using a universal testing machine (Instron, 5848 Microtester, USA). The load was applied with a crosshead speed of 1mm/min until debonding occurred, and then the micro-tensile stress was automatically measured through Bluehill software. After micro-tensile bond strength testing, the mode of failure of the debonded specimens was analyzed using a stereomicroscope (40X).