Effect of simulated orthodontic forces on fluoride-induced cytotoxicity in MC3T3-E1 osteoblast-like cells.

The effects of simulated orthodontic forces such as centrifugal force or water pressure on sodium fluoride (NaF)-induced cytotoxicity against mouse osteoblast-like cells MC3T3-E1 were investigated. Loading with centrifugal force (44.5 g/cm2) or water pressure (5 g/cm2) slightly reduced the cell proliferation and additively enhanced the cytotoxic activity of millimolar concentrations of NaF.

Selective toxicity and type of cell death induced by various natural and synthetic compounds in oral squamous cell carcinoma.

This article reviews the selective toxicity and type of cell death induced in oral squamous cell carcinoma (OSCC) by hundreds of natural and synthetic compounds. Flavonoids, coumarins, tannins, ketones and other synthetic compounds showed low to moderate tumor-specific cytotoxicity against human OSCC cell lines as compared with normal human oral cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast), whereas anthracyclines, nocobactins and cyclic alpha, beta-unsaturated compounds showed much higher tumor-specific cytotoxicity. No strict relationship was found between the tumor-specific cytotoxicity and apoptosis induction.

Enhancement of cytotoxic activity of sodium fluoride against human periodontal ligament fibroblasts by water pressure.

Whether or not water pressure enhances the cytotoxic activity of sodium fluoride (NaF) against human periodontal ligament fibroblast (HPLF) was investigated. Loading with water pressure (up to 5 g) alone did not affect the cell proliferation, but significantly enhanced the cytotoxic activity of millimolar concentrations of NaF. Cytotoxic activity of NaF was reduced by supplementation with Ca2+, whereas it was enhanced by removal of Ca2+ from the culture medium.

Enhancement of sodium fluoride-induced cell death by centrifugal force.

As an initial step in the study of the influence of orthodontic force on cellular function in vitro, the effects of centrifugal force on the cytotoxicity induced by various apoptosis inducers were investigated. When human oral squamous cell carcinoma (HSC-2) and human promyelocytic leukemia (HL-60) cell lines were treated with increasing magnitudes of centrifugal force (evaluated by g-value), the viability assessed by the MTT method and trypan blue dye exclusion began to decline. Centrifugal force enhanced the cytotoxicity of sodium fluoride (NaF), but not that of redox compounds (hydrogen peroxide, sodium ascorbate, gallic acid) or chemotherapeutic agents (daunorubicin, doxorubicin, idarubicin, mitoxantrone, peplomycin, 5-FU).