The critical cooling rate and fluorescence properties of lithium (Li) disilicate glasses and glass-ceramics, doped with 2.0 wt% CeO2 and with up to 0.7 wt% V2O5 and 0.3 wt% MnO2 added as colorants, were investigated. The critical cooling rates, R-c, of glass melts were determined using differential thermal analysis and were found to be dependent on the relative concentrations of V2O5 and MnO2, decreasing from 25 +/- 3 degrees to 16 +/- 3 degrees C/min. Annealed glasses were heat treated first to 670 degrees C, and then to 850 degrees C to form Li metasilicate and Li disilicate glass-ceramics, respectively. The fluorescence intensities of the Ce-doped glasses and glass-ceramics decrease by a factor of 100 with the addition of the transition metal oxides. This optical quenching effect is explained by the association of the Ce3+ ions with the transition metal ions in the residual glassy phase of the glass-ceramics.