The Effect of Chitosan-Based Novel Etchant on Dentin Enzymatic Activity

Objectives: During the acid-etching step of the restorative procedures, host-derived endogenous enzymes are activated.These enzymes have been thought to contribute to the progressive degredation of collagen fibrils in hybrid layers. This study evaluated the effect of chitosan-based novel etching gel on enzymatic activity of dentin collagen matrix..The tested hypothesis was that the demineralizing agent has no influence on the host-derived enzyme activation of the collagen matrix.
Methods: Demineralized dentin beams (1x2x6 mm)(n=10/group) were divided into 5 groups after baseline dry mass measurements and treated with 1%, 2% or 3% chitosan- gel etchant or 37% phosphoric acid (PA) for 1 min and rinsed. Untreated demineralized beams served as controls. After treatment, the direct effect of chitosan etching gel on the total enzymatic activity was evaluated using a generic MMP activity assay, SensoLyte" Generic MMP Assay Kit (AnaSpec, CA, USA). Treated beams were incubated with thiopeptolide proprietary substrate. After incubating the plates at 37°C for 2 hr, the developed color was measured at 412 nm. The demineralization pattern on dentin surface changes were evaluated by SEM. Data were analyzed using ANOVA, α = 0,05.
Results: ANOVA showed significant differences among tested chitosan concentrations ,PA, and non-treated dentin matrix (p<0.001) . Chitosan-gel showed a reduction in total MMP activity with the increasing percent of chitosan. SEM evaluation also confirmed selective removal of minerals in chitosan-gel treated dentin.
Conclusions: The use of chitosan based etching gel resulted in significant reduction in host-derived endogenous enzymatic activity in demineralized dentin matrices when compared to PA. These results provide insights on the potential use of chitosan-based etchants as an alternative to PA in adhesive dentistry.