Toxicity of Flow Line, Durafill VS, and Dycal to dental pulp cells: effects of growth factors.

INTRODUCTION: The objective was to determine the effects of growth factor treatment on dental pulp cell sensitivity to toxicity of 2 composite restoration materials, Flow Line and Durafill VS, and a calcium hydroxide pulp capping material, Dycal.

METHODS: Toxicity of the dental materials to cultures of primary dental pulp cells was determined by the MTT metabolism assay. The ability of 6 different growth factors to influence the toxicity was tested.

RESULTS: A 24-hour exposure to either Flow Line or Durafill VS caused approximately 40% cell death, whereas Dycal exposure caused approximately 80% cell death. The toxicity of Flow Line and Durafill VS was mediated by oxidative stress. Four of the growth factors tested (bone morphogenetic protein [BMP]-2, BMP-7, epidermal growth factor [EGF], and transforming growth factor [TGF]-beta) decreased the basal MTT values while making the cells resistant to Flow Line and Durafill VS toxicity except BMP-2, which made the cells more sensitive to Flow Line. Treatment with fibroblast growth factor-2 caused no change in basal MTT metabolism, prevented the toxicity of Durafill VS, but increased the toxicity of Flow Line. Treatment with insulin-like growth factor-I (IGF-I) increased basal MTT metabolism and made the cells resistant to Flow Line and Durafill VS toxicity. None of the growth factors made the cells resistant to Dycal toxicity.

CONCLUSIONS: The results indicated that growth factors can be used to alter the sensitivity of dental pulp cells to commonly used restoration materials. The growth factors BMP-7, EGF, TGF-beta, and IGF-I provided the best profile of effects, making the cells resistant to both Flow Line and Durafill VS toxicity.