Objectives: The aim of this study is to evaluate the effect of the endodontic treatment on the fatigue resistance of endodontic post adhesive interfaces. Materials and methods: 50 single-rooted human teeth have been severed at the cement-enamel junction and randomly assigned to 5 groups receiving different endodontic treatments as follows: 1) distilled water + gutta-percha (control); 2) NaOCl 5% + gutta-percha and Pulp Canal Sealer EWT (Kerr); 3) NaOCl 5% + gutta-percha and Top Seal (Dentsply-Maillefer); 4) NaOCl 5% and EDTA 10% (alternatively) + gutta-percha and Pulp Canal Sealer EWT; 5) NaOCl 5% and EDTA 10% (alternatively) + gutta-percha and Top Seal. Subsequently, Light-Post DT #2 quartz fiber posts (RTD, France) have been placed in the root canal using All-Bond 2 adhesive and Bisfil 2B cement (Bisco). Five specimens from each group have been subjected to 2.000.000 fatigue cycles ranging from 0 to 37.5 N at 8Hz frequency and 37°C water irrigation, whereas the remaining were stored in distilled water at room temperature. After the fatigue cycles, all the specimens were severed obtaining 4 sections from each tooth, which were evaluated with the push-out test at a constant speed of 1mm/min. Stereomicroscope and SEM observation were done to evaluate the interface failures. Results: no statistically significant differences were observed between the five groups in both fatigue stressed (P=0.298) and water stored specimens (P=0.093). Also, the microscope analysis of interface failures showed that the post-cement interface is weaker than the cement-dentin one. The difference was significant with P=0.001. Conclusions: the results suggest that the interface resistance is not influenced by the canal treatments adopted in this study. Probably, the hard tissue removal necessary for post placement eliminates contaminated or altered dentin that may affect the bonding with the luting cement. High resistance of cement-dentin interface strongly supports this last hypothesis.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2003|