Figure 2

The amount of collagen biodegradation of demineralized dentin after challenge with collagenase. (a) Collagenase type I; (b) Collagenase type II. Amount of collagen degradation in ×10−4, m/m. *Significantly lower collagen biodegradation was observed in the 2% CHX group than the untreated group at the same time point (P<0.05). **PA preconditioning significantly reduced the collagen biodegradation compared with the other groups, regardless of PA concentration and treatment duration (P<0.01). CHX, chlorhexidine; PA, proanthocyanidin.