In vitro evaluation of gamma irradiation versus autoclaving on the morphology and regenerative potential of Allo-demineralized dentin matrix

Abstract

BACKGROUND: Demineralized dentin matrix (DDM) can serve as a novel scaffold for dental tissue regeneration. This study aimed to assess the impact of two distinct sterilizing methods on morphology of Allo-DDM as well as on the viability, metabolic activity, and alkaline phosphatase (ALP) activity of bone marrow mesenchymal stem cells (BMMSCs). METHODS: Allo-DDM scaffolds were prepared from human-extracted premolars and sterilized using two different techniques. These scaffolds were examined using scanning electron microscopy (SEM) to assess their morphology and by Energy Dispersive X-ray Spectroscopy (EDAX) to assess the scaffolds' mineral content. BMMSCs were grouped into four groups: [1] Collagen group (positive control): Stem cells received a collagen scaffold; [2] Gamma-ray group(G-DDM): Stem cells received gamma-sterilized DDM scaffold; [3] Autoclave group(A-DDM): Stem cells received autoclave-sterilized DDM scaffold), and [4] Negative Control group: Stem cells were provided with culture media only. Cell viability and metabolic activity were assessed using trypan blue and MTT assays, while cell differentiation was evaluated using the alkaline phosphatase (ALP) assay. RESULTS: SEM micrographs revealed that G-DDM had a higher number of dentinal tubules than the A-DDM group, while there were no significant differences between G-DDM and A-DDM in the EDAX analysis. Cell viability and metabolic activity assessment showed that the collagen group had significantly higher viability, followed by G-DDM, while A-DDM and negative control groups did not improve BMMSC viability metabolic activity after 48 h. The ALP assessment revealed that cells significantly differentiated in collagen and G-DDM groups than in A-DMM and control groups. CONCLUSION: Gamma sterilization more effectively preserved the structural, chemical, and biological characteristics of Allo-DDM scaffolds compared to autoclaving. Gamma-treated scaffolds outperformed autoclaved scaffolds in terms of cell survival, metabolic activity, and ALP activity.