Cytotoxicity of mesoporous calcium silicate biomaterials for treating dentin hypersnsitivity

Introduction: The treatments of dentin hypersensitivity so far do not lead to satisfactory clinical outcome. Our previous study showed that gelatin-templated calcium silicate mesoporous (GCSM) with 30% H3PO4 could efficiently occlude dentinal tubules without eroding dentin and thus have great potential in treating dentin hypersensitivity. Objectives: The aim of this study was to investigate the cytotoxicity of GCSM to conceive the feasibility for treating dentin hypersensitivity clinically. Materials and Methods: The GCSM biomaterial was synthesized using mesoporous silica as carrier, impregnated with CaO precursor and calcinated at 400°C for 5 hrs. The cytotoxic effect of GCSM and GCSM with 30% H3PO4 (pH 5.0-5.5) on reactive oxygen species (ROS) and the viability of dental pulp cells was investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and lactate dehydrogenase (LDH) assays. Commercial product Seal&Protect served as comparison. Results: MTT assay revealed that the cell viability of GCSM, combination of GCSM and 30% H3PO4, Seal&Protect, and control groups. The OD values were 0.833, 0.468, 0.053, and 0.796, respectively. ROS and LDH results showed that no significant difference between GCSM and the control group. TUNEL and MTT assays revealed GCSM did not reduce the cell viability. Comparing with Seal&Protect group, GCSM group or GCSM/H3PO4 showed significantly (p<0.0001, ANOVA) lower cytotoxicity in one day cell proliferation. Similar pattern has been found in cells proliferated for three days. Conclusion: This study demonstrated that the cytotoxicity of our developed GCSM paste was low and feasible for treating dentin hypersensitivity clinically.