Evaluation of 5% proanthocyanidin and 30% alpha-tocopherol on shear bond strength of composite to bleached enamel: An In vitro study

Objective: The aim of this in vitro study is to evaluate and compare the effect of 5% proanthocyanidin and 30% alpha-tocopherol on the bond strength of composite resin to the bleached enamel. Materials and Methods: The labial enamel surface of sixty central incisors was flattened for the purpose of this study. Fifteen teeth served as control group which did not receive bleaching nor antioxidant treatment. The remaining 45 teeth then were randomly divided into three groups of 15 each. They are Group 1: bleaching with 38% hydrogen peroxide for 10 min without the use of antioxidant, Group 2: bleaching followed by treating with 5% proanthocyanidin, and Group 3: bleaching followed by treating with 30% alpha-tocopherol. The bonded specimens were stored in distilled water (37°C, 24 h) and tested for shear bond strength in a universal testing machine. The data were analyzed with one-way ANOVA and Tukey's post hoc test. Results: Higher bond strength values were seen in the control group followed by 5% proanthocyanidin group. Conclusion: Use of 5% proanthocyanidin can effectively reverse the bond strength of bleached enamel

Immunophenotypic profiles and prognosis for colorectal mucinous adenocarcinomas are dependent on anatomic location

Abstract Background The prognostic value of mucinous adenocarcinomas (MCAs, exhibiting >50% extracellular mucin) of the colorectum, in relation to their anatomic location is not well studied. Materials and Methods We compared MCAs (n = 175) with non‐MCAs (NMCAs, n = 1015) and the cancer‐specific survival rates were evaluated, based on their anatomic site, by univariate Kaplan–Meier and multivariate Cox methods. Subsets of these tumors were immunostained for MUC1, MUC2, Bcl‐2, and p53. Results MCAs were more commonly found in the right colon, were of high‐grade, and were more prevalent in younger patients (<40 years). They exhibited strong expression of MUC2 and Bcl‐2 and showed less p53 nuclear staining. In contrast, most NMCAs were low‐grade with high expression of MUC1. MCAs of the rectum were associated with poorer outcomes relative to NMCAs (HR 1.85, CI 95% 1.15–2.97), even though the distributions of advanced‐stage tumors were similar. Conclusion Late‐stage disease and age were poor independent prognostic indicators of cancer‐specific deaths across all tumor locations. In summary, rectal MCAs have a poor prognosis