ABSTRACT
BACKGROUND: Medium-term evaluate the bond strength and tag formation in root dentin using self-adhesive cements Maxcem Elite (MCE), Relyx U200 (RU2), SeT PP (SPP) and Megalink (MGL) compared to conventional cement Relyx ARC (ARC) for glass fibre post cementation. MATERIALS AND METHODS: One hundred bovine incisors roots were endodontically treated and divided into 5 groups (n = 20) according to the cementation system: MCE, RU2, SPP, MGL and ARC. All cementation systems were evaluated at 24 h (1) and 12 months (2) after post cementation. Specimens from the cervical, middle and apical thirds of the root were submitted to push-out bond strength test and confocal laser microscopy to verify the dentin penetration. The adhesive failure mode was classified as adhesive, cohesive and mixed. Data were analysed by one-way ANOVA and Tukey tests (α = 5%). RESULTS: ARC-1 and ARC-12 showed the highest bond strength (P < 0.05). ARC showed the greatest tag extension, regardless of the third (P < 0.05). The most frequent failure mode in the 24-h analysis was cohesive, regardless of the cement used. For the 12-month analysis, mixed failure was the most frequent. CONCLUSION: Conventional cement (ARC) showed the highest bond strength and tag extension, regardless of the evaluation period. In all cementation systems, the bond strength decreased after 12 months. © 2023 Australian Dental Association.
ABSTRACT
PURPOSE: The aim of this study was to evaluate the effects of a new irrigant solution on the post space cleaning and the adhesive resistance of fiber posts. METHODS AND MATERIALS: Eighty roots of bovine teeth were randomly allocated into eight groups (n=10 for each group). Evaluations were performed in two different time points for each irrigant. The irrigants included a control group with distilled water (DW), 2.5% NaOCl and 17% EDTA (SH), 1% peracetic acid (PA), and 5% boric acid and 1% citric acid (EX). The time points were 24 hours (I-immediate) and 6 months (D-delayed). The push-out test was performed using a universal testing machine with a 5 kN load cell operating at a crosshead speed of 0.5 mm/minute. The dentinal cementation system was analyzed using a laser confocal microscope (LSM5, Zeiss, Jena, Germany), and incidence of residue on radicular dentin was evaluated by scanning electron microscopy (SEM). The incidence of residue was evaluated by the Kruskal-Wallis test and push-out bond strength and dentin penetrability were evaluated via a one-way analysis of variance (ANOVA) and Tukey tests (α=0.05). RESULTS: The EX irrigation protocol demonstrated the lowest incidence of residue on the dentin surface (p<0.05), independently of the evaluated third. In the cervical and the middle post thirds, EXI, EXD, SHI, and SHD groups exhibited similar push-out bond strength values (p>0.05). EXI, EXD, PAI, and PAD exhibited the greatest dentinal penetrability of the cementation system in all the post thirds (p<0.05). CONCLUSIONS: A solution containing 5% boric acid and 1% citric acid can be a promising irrigant for radicular post space cleaning. It has adequate potential for cleaning the dentin surface without interfering with the adhesive interface between the dentin and the cementation system.
