Avaliação da resistência de união e resistência à fratura de dentes com canais radiculares alargados aplicando diferentes técnicas restauradoras

Abstract

The objective of this study was to compare the using of anatomical glass fiber post using bulk-fill composite resin with CAD-CAM milled glass fiber post in oversized root canals, through of bond strength (BS) and fracture resistance (FR) tests. It was selected 48 single-rooted permanent teeth, where half had their crowns removed immediately after the cement-enamel junction (CEJ) and the other half had their crowns removed 2 mm above the CEJ, having their roots treated endodontically. After one week, the standard preparation of the canals was carried out and the roots were divided into 3 groups (n = 16), according to the use of different restorative techniques: Control - prefabricated glass fiber post (PFP), direct anatomical glass fiber post (AFP) and milled glass fiber post (MFP). After the cementation of the posts, for 8 teeth in each group, six specimens (slices) were obtained, which were distributed in the following way: coronary third (two slices), middle third (two slices) and apical third (two

slices). For the remaining 8 roots of each group, standardized preparations for metal- free crowns, milling of 5 mol % yttria-stabilized tetragonal zirconia polycrystalline - 5Y- TZP and cementation the crowns were performed. Then, for each group, all slices were

evaluated in BS through the push-out test and the 8 roots with cemented crowns were evaluated in compression FR. The data obtained from BS were submitted to two-way ANOVA (group vs. root region) and Tukey (α = 0.05), and from FR to one-way ANOVA (group) and Tukey (α=0.05). For the BS test, MFP group was statistically superior to the PFP group in all root regions and was statistically superior to the AFP group only in the cervical region, being statistically similar in the middle and apical root regions. For the FR test, the MFP group was statistically superior to the PFP and AFP groups. It can be concluded that the milled fiber post technique can be a great alternative in the restoration of weakened roots with flared root canals.