The Influence of Demineralization Process on Physicochemical Characteristics, BMP-2 Quantification of Human Demineralized Tooth Matrix

Objectives: To examine the influence of demineralization process using 4 different concentrations and reaction times of HCl acid on physicochemical properties, BMP-2 releasing and degradation rate at 30 days of human tooth matrix. Materials and methods: Tooth particles with size 500-1,000 µm were divided to 5 groups: 0M/0min, 0.5M/10min, 0.5M/20min, 1M/10min and 1M/20min. Chemical compositions were analyzed by XRD and XRF. Surface morphology was observed by SEM and BET analysis. Bradford protein assay was used to quantify total protein and human ELISA kit was used for BMP-2 quantification. Degradation rate was assessed by using 50 mM Tris-HCl solution for 30 days. Results: Increasing reaction time led to more collagen exposed, larger dentinal tubules, less crystallinity, and less calcium-phosphate percentage but increased Ca/P ratio. The highest total protein and BMP-2 concentration were found in 1M/20min group compared to 0M/0min (p=0.000). Increasing HCl concentration led to more degradation rate. Conclusions: The reaction time of HCl had effect on tooth particles in aspect of surface morphology, crystallinity, element components, Ca/P ratio, quantity of BMP-2 releasing while increasing concentration led to more degradation. Keywords: bone graft, tooth, demineralization, hydrochloric acid, BMP-2, degradation