Glass ionomers and discoloration: a comparative study of the effects of tea and coffee on three brands of glass ionomer dental cement.
This study was undertaken to compare the in vitro discoloration of 3 brands of glass ionomer dental cement, Chemfil, Fuji Type II, and Ketac-Fil. Forty-eight specimens of each brand were prepared. Sixteen specimens of each brand were placed in tea, coffee and, as a control, water. Discoloration was evaluated by means of reflection spectrophotometry at 2, 4, 8, and 16 wk. Analysis of the data indicated that most discoloration occurred during the first 2 wk of immersion in the staining media and a little further discoloration took place between 2 and 16 wk (p less than 0.05). Tea discoloured glass ionomer more than did coffee (p less than 0.05) and Fuji Type II discoloured the most, Ketac-Fil the least whilst the discoloration of Chemfil lay between these two (p less than 0.05).