Application quality of root canal dressing with gel/cannule and paste/lentulo

40 lower incisors with one root canal were randomly assigned into two groups. 20 teeth were instrumented using rotary instruments to a size 0.04/25, and 20 teeth to a size 0.04/30. 5 teeth from each group were randomly assigned into four treatment groups: CHX/BaSo4/cannule, CHX/Ca(OH)2/BaSo4/cannule, CHX/Ca(OH)2/BaSo4/lentulo and Ca(OH)2/BaSo4/lentulo. Teeth were radiographed in two planes. After that, the teeth were cleaned and the experiment was repeated, until n=20 samples were measured in every group. We measured the depth of penetration (mm to apex) and the homogeneity (four classes). Statistical processing was done with ANOVA (depth of penetration) and nonparametric tests (homogeneity). There was no statistical effect of material or instrumentation size on penetration depth. The application of a gel with a lentulo results in reduced homogeneity (p=0.031). We conclude that a gel can be applicated as an endodontic dressing with a cannule and high pressure even in root canals with small preparation size. The application of a gel with a lentulo is not recommended.