Intratubular penetration in post cementing: A comparative study between a total etching system and a self-etching cement.

PURPOSE: To analyze the penetration depth and percentage perimeter with penetration of two fiber post cementing systems using confocal laser scanning microscopy (CLSM). METHODS: 20 maxillary incisors were shaped with the Mtwo system and filled using lateral condensation and TopSeal mixed with fluorescein. Fiber posts were cemented. The samples were divided into two groups of 10 teeth each, according to the post cementing technique used: Prime&Bond NT combined with Rebilda DC using a total dentin etching technique (Group 1); or BisCem a self-adhesive cement (Group 2). Rhodamine B was incorporated in the adhesive systems. Cross-sections were prepared, with the selection of three sections (coronal, middle and apical thirds). CLSM was used to measure the percentage perimeter of the root canal showing penetration of the endodontic cement and of the adhesive system in the dentin tubules, together with the maximum penetration depth. The nonparametric Mann-Whitney U-test was used to compare the data referred to each of the three tooth sections between the two study groups. The Friedman test was used to compare the variables by coronal, middle and apical thirds within each group. RESULTS: Greater penetration was recorded with the BisCem system in all thirds, with statistically significant differences in the case of the middle and apical thirds (P = 0.001). The percentage perimeter with penetration was also greater in all thirds with the BisCem system, though without significant differences between the two groups. Penetration depth and percentage were found to decrease in the coronal to apical direction in both groups.