In Vitro Cytotoxicity Of Three Dentin Desensitizers On L929Cells

Dentinal hypersensitivity is a very common clinical symptom with high prevalence.Topical application of dentin desensitizers is the most common form of treatment and it isrecommended by both doctors and patients because of its easy application and little injury.Desensitizing agents contain many toxic components, such as glutaraldehyde,benzethonium chloride and fluoride et al. In this study, the cytotoxic effects of three dentindesensitizers(Gluma Desensitizer, Pulpdent Dentin Desensitizer, and Vivasens) wereevaluated in mouse fibroblast cells(L929) in vitro. The tested desensitizers were dilutedinto5different concentrations(0.1,0.3,0.5,1.0,1.5μl/mL).To monitor L929cells viability,(MTT)colorimetric assay was used. To examine the survival of L929cells, fluorescentLive/Dead viability assay was used.To investigate the expression of proliferating cellnuclear antigen(PCNA) in L929cells, immunohistochemical technique was used.MTT assay result indicated that after exposure to desensitizer solution of differentconcentrations(0.1,0.3,0.5,1.0,1.5μl/mL),the OD value of Gluma and Pulpdent weresignificantly different from the control（P＜0.05）,and the OD value decreased as theconcentration increasing.There was no significant difference between the OD value ofGluma and Pulpdent（P＞0.05）.At the concentration of1.5μl/mL and0.1μl/mL, the ODvalue of Vivasens were significantly different from the control, and there was irrelevantrelationship between the OD value and the concentration of Vivasens. According to the teststandard of USP,the cytotoxicity of Gluma and Pulpdent at the concentration of0.1μl/mLwas1grade,that of0.3and0.5μl/mL was2grade,that of1.0μl/mL was3grade,that of1.5μl/mL was4grade,and the cytotoxicity of Vivasens at all the concentrations was0grade.The result of Live/Dead assay indicated that at the concentration of0.3and0.5μl/ml, thecell death rate of Gluma and Pulpdent were significantly higher than Vivasens and control.The cell death rate increased as the concentration increasing. The cell death rate ofVivasens was no significantly different with control.The result of PCNAimmunofluorescence indicated that at the concentration of0.5μl/mL,the positive cell rate ofGluma and Pulpdent were significantly lower than Vivasens and control. The positive cellrate of Vivasens was no significantly different with control. There was no significantdifferece between the positive cell rate of Gluma and Pulpdent.In conclusion,Gluma Desensitizer and Pulpdent Dentin Desensitizer have cytotoxic effects on L929cells, and are relevant to the concentration.By contrast, Vivasens has nosignificant cytotoxicity. Cytotoxic effects may be determined by the chemical compositionand exposure time of the tested desensitizers.