Effects of an intracanal glass ionomer barrier on coronal microleakage in teeth with post space

Bacterial microleakage of the remaining gutta-percha in teeth prepared for post space with and without the use of an intracanal glass ionomer barrier was evaluated. Forty distal roots of mandibular molars were instrumented, obturated with gutta-percha and AH Plus sealer, and post spaces created. Teeth were divided as follows: Group I, 3 mm of gutta-percha; group II, 4 mm of gutta-percha; group III, 2 mm of gutta-percha plus 1 mm of Vitrebond; and group IV, 3 mm gutta-percha plus 1 mm Vitrebond. The roots were suspended in Rogosa SL broth and Lactobacilli casei was used as a microbial marker. At the end of 92 days, the mean number of days for the broth to turn turbid was group I, 23.8; group II, 43.0; group III, 57.4, and group IV, 70.5. A two-way ANOVA showed differences between the groups and a post hoc Tukey HSD analysis revealed the following significant differences (p < 0.05): Group I leaked faster than groups III and IV and group II leaked faster than group IV. In clinical situations of teeth with compromised crown-root ratio that require a post and core, 1 mm of Vitrebond over 2 or 3 mm remaining gutta-percha could reduce the risk of recontamination of the apical gutta-percha.