Influence of powder/liquid ratio on the radiodensity and diametral tensile strength of glass ionomer cements

Clinicians tend to make reductions in glass ionomer power/liquid (p/l) ratios since some materials are difficult to mix and flow into small cavities,grooves or pits. in general,changing the p/l ratio decreases the physical and mechanical properties of conventional glass ionomer cements (gics) and resin modified glass ionomer cements (rmgics),but alterations seem to depend on their composition. objective: to determine the influence of p/l ratio on the radiodensity and diametral tensile strength (dts) of glass ionomer cements. material and methods: there were 2 factors under study: p/l ratio (manufacturer's recommended p/l ratio and a 50% reduced p/l ratio),and materials (vitro molar,vitro fil,vitro cem conventional gics and vitro fil lc,ortho glass lc rmgics. five 1-mm-thick samples of each material-p/l ratio were produced for radiodensity evaluation. samples were x-ray exposed onto digora phosphor plate and radiodensity was obtained using the software digora for windows 2.5 rev 0. for dts,five (4.0×8.0 mm) cylinder samples of each material were tested (0.5 mm/min). data were subjected to one- and two-way anova (5×2) followed by tukey's hsd test,or kruskal-wallis and dunn's method. for paired comparisons,t-test or mann-whitney test were used (α=0.05). results: there was a significant interaction (p=0.001) for the studied factors (materials vs. p/l ratio). reduced p/l ratio resulted in significantly lower dts for the rmgics,but radiodensity was affected for all materials (p<0.05). conclusions: reduced p/l ratio affected properties of the tested glass ionomer cements. rmgics were more susceptible to lower values of dts,but radiodensity decreased for all materials following p/l ratio reduction.