The cell viability of porcine TMJ disc cells. The data shown were means and 95% confidence intervals. Experiments were performed in triplicate on three independent experimental days (n=9). Absorbance values were normalized to the control (25 mM glucose and 21% oxygen level). The effects of oxygen levels (1%, 5%, 10%, and 21%) and glucose concentrations (0, 1.5, 5, and 25 mM) were assessed. An increase of glucose concentration significantly increased TMJ disc cell viability (P < 0.0001). In the presence of glucose, an increase of oxygen level significantly decreased cell viability (P < 0.0001). The interaction between oxygen and glucose was significant (P < 0.0001). Significance (P < 0.05) of oxygen level effect and glucose level effect are denoted by a * and #, respectfully.