Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study.

AIM: The aim of this present study was to compare the dislodgement resistance of calcium silicate-based sealer, zinc oxide sealer, and a new sealer combining both zinc oxide and calcium silicate-based sealer in vitro. MATERIALS AND METHODS: 60 single-rooted human teeth were instrumented with F3 Protaper Gold. All endodontic canals were filled using gutta percha cones using the cold lateral condensation technique in combination using one of the mentioned sealers (n = 20 per group). The teeth were divided into three groups: group A consisted of Sealite® Ultra, group B consisted of K-Sealer®, and group C consisted of BioRoot® RC. After 2 months of incubation (37°C, 100% humidity) and after cutting out 2 mm from the most apical portion of the root apex, six slices of 1 mm thickness were generated. Mechanical dislodgement resistance was examined using a universal pressure-testing machine and the push-out bond strength (POBS) was calculated. Specimens were examined under 20× magnification to define the bond failure mode. Statistical analysis was executed using ANOVA, post hoc Turkey test for pairwise comparisons and Kruskal-Wallis tests. RESULTS: The POBS of BioRoot® was significantly higher than the POBS of the two other sealers with a mean of 10.54 MPa ± 2.10 and 5.73 MPa ± 2.34, respectively (p < 0.001). Sealite® and K-Sealer® showed similar results in the median and coronal part. K-Sealer® revealed highest POBS compared with Sealite® in the apical part (p < 0.05). CONCLUSION: The POBS of the zinc oxide and calcium silicate-based sealer was significantly lower compared with calcium silicate. Sealite® and K-Sealer® exhibited almost same results. BioRoot showed the highest POBS of all sealers. CLINICAL SIGNIFICANCE: The current study was needed to evaluate the bond strength of three different cements to dentinal walls, by evaluating their respective POBS in vitro. The findings of this study may provide guidance for the clinician in the selection of an adequate endodontic sealer that guarantees an enhanced adhesive seal between the Gutta-percha and the dentinal canal walls. How to cite this article: Makhlouf MP, El Helou JD, Zogheib CE, et al. Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study. J Contemp Dent Pract 2024;25(1):15-19.

Improved outcomes after aortic valve surgery for chronic aortic regurgitation with severe left ventricular dysfunction.

OBJECTIVES: Among patients undergoing aortic valve surgery for chronic aortic regurgitation (AR), we sought to: 1) compare survival among those with and without severe left ventricular dysfunction (LVD); 2) identify risk factors for death, including LVD and date of operation; and 3) estimate contemporary risk for cardiomyopathic patients. BACKGROUND: Patients with chronic AR and severe LVD have been considered high risk for aortic valve surgery, with limited prognosis. Transplantation is considered for some. METHODS: From 1972 to 1999, 724 patients underwent surgery for chronic AR; 88 (12%) had severe LVD. They were propensity matched to patients with nonsevere LVD to compare hospital mortality, interaction of operative date with severity of LVD, and late survival. Propensity score-adjusted multivariable analysis was performed for all 724 patients to identify risk factors for death. RESULTS: Survival was lower (p = 0.04) among patients with severe LVD than among matched patients with nonsevere LVD (30-day, 1-, 5-, and 25-year survival estimates were 91% vs. 96%, 81% vs. 92%, 68% vs. 81%, and 5% vs. 12%, respectively). However, survival of patients with severe LVD improved dramatically across the study time frame (p = 0.0004): hospital mortality decreased from 50% in 1975 to 0% after 1985, and time-related survival in patients with severe LVD operated on since 1985 became equivalent to that of matched patients with nonsevere LVD (p = 0.96). CONCLUSIONS: Neutralizing risk of severe LVD has improved early and late survival such that aortic valve surgery for chronic AR and cardiomyopathy is no longer a high-risk procedure for which transplantation is the best option.