The aim to determine the collagenolytic activity following bleaching in non- vital teeth and methods employed to counteract it using FT-Raman spectroscopy. 25 extracted non- carious human third molars were obtained. The teeth were stored in thymol solution at 4˚C and used within 1 week after extraction. Dentin disks were obtained from the mid-coronal portion of each tooth, 50 dentin beams were obtained. They were divided into five groups (n=10) and subjected to the following treatment Group A: Untreated dentin. Group B: Dentin disks bleached in 35% hydrogen peroxide.Group C:10% sodium ascorbate was applied on bleached dentin disks. Group D:0.2% chlorhexidine digluconate was applied on bleached dentin disks. Group E:10% sodium ascorbate followed by 0.2 chlorhexidine digluconate was applied on bleached dentin disks. The collagenolytic changes were observed using Raman transform infrared spectroscopy. Concluded that use an antioxidant & a MMP inhibitor to preserve the structural integrity of the collagen following bleaching.
