Future Dental Journal of Egypt


Aim: Evaluation of the effect of coating, staining beverages and aging on the color stability and hardness of recently introduced glass ionomer (GI) restorative material and to determine whether there was a correlation between these two variables. Materials and methods: Two commercially available conventional GI restorative materials were used; Ketac™ Universal Aplicap™ and Ketac™ Fil Plus Aplicap™ GI restoratives. A total of 84 disc-shaped specimens (5×2 mm) were prepared and divided into 3 main groups (n=28). Fifty six specimens were prepared from Ketac Universal Aplicap where half of them was coated (CU) and the other half was uncoated (U) and 28 coated specimens from Fil Plus Aplicap™ (CF) that act as a control group. Coating was performed with Ketac Glaze. Each group was further subdivided into 4 subgroups (n=7) according to the beverages (tea, coffee, coke and distilled water). Color changes (ΔE) and hardness (MPa) were measured by scanning spectrophotometer and Vickers's hardness (VH) test respectively. Measurements were recorded at the baseline, after 7 and 30 days of aging in each beverage. Chemical analysis of the glass powders was performed by EDXA. Additionally, the filler size was examined by the SEM. The data were statistically analyzed (P≤0.05). Results: The CU subgroups possessed lower ΔE than U subgroups in tea and coffee. The impact of staining beverages and aging on the ΔE was material's dependent. The CU subgroups recorded higher VH than the U and CF subgroups after aging in coke (30 days). Aging of the U subgroups in tea and coke significantly decreased its VH. The SEM revealed smaller average filler size in Ketac Universal Aplicap (7.2 μm) than Ketac Fil Plus Aplicap (17.9 μm). Clinical significance: It is advisable to use the recently introduced uncoated GI restorative material for patients who are not consuming tea and/or coffee but with surface protection to maintain its color acceptability up to 3 year clinically. Not all color changes could be associated with surface degradation.