Effect of bleaching agents on sealing properties of different intraorifice barriers and root filling materials

Objective: To evaluate the effect of intracoronal bleaching agents on the sealing properties of different intraorifice barriers and root filling materials.Study Design: The root canals of extracted human premolars (n=180) were prepared by using System GT rotary files and filled with either gutta-percha+AH Plus or Resilon+Epiphany sealer. In both groups, the coronal 3mm of root filling was removed and replaced with one of the following materials applied as intraorifice barriers (n=30/group): 1. ProProot-MTA; 2. Conventional Glass ionomer cement; and 3. Hybrid resin composite. In each subgroup, intracoronal bleaching was performed using either sodium perborate with distilled water or 35% hydrogen peroxide gel for 3 weeks. The leakage of specimens was measured using fluid-filtration and dye penetration tests. The data were analyzed statistically with One-way ANOVA, Repeated Measures t-test and Independent Samples t-test (p=0.05). Results: The fluid conductance values of the test groups were not influenced by the type of the bleaching agent, the intraorifice barrier, or the root filling material (all p>0.05). However, the extent of dye leakage was significantly affected by the type of intraorifice barrier material (p<0.05), which showed the following statistical ranking: glass ionomer cement > resin composite > ProRoot-MTA (p<0.05).Conclusions: The effect of 35% hydrogen peroxide gel or sodium perborate/distilled water on the sealing properties of tested intraorifice barriers and root filling materials varied conforming leakage assessment. These properties were not affected by using fluid filtration test, while the glass ionomer barrier showed the greatest amount of dye leakage in both gutta-percha and Resilon root-filled teeth. Key words:Tooth Bleaching, root canal filling materials, glass ionomer cement, mineral trioxide aggregate, micro leakage     

Bilateral and symmetrical heterotopic submandibular glands in the upper neck: case report

During the neck dissection of a male cadaver, large heterotopic submandibular glands were encountered bilaterally in the upper neck. They were symmetrical, capsulated and lay deep to the superficial lamina of the superficial cervical fascia. Both glands were located in the submandibular and carotid triangles. The somewhat smaller orthotopic submandibular glands and the sublingual glands were in their normal anatomic location. Duct of the heterotopic gland united with the corresponding orthotopic submandibular gland’s duct on each side and ended on the ipsilateral sublingual caruncle. Histopathologic examination of the heterotopic glands revealed seromucous (mainly serous) tissue. A bilaterally situated symmetrical heterotopic submandibular gland of this size has not heretofore been reported in the literature. The embryological and clinical significance of this case is discussed.     

Preconditioning with levosimendan prevents contractile dysfunction due to H2O2-induced oxidative stress in human myocardium

We studied the inotropic and possible antioxidant effects of levosimendan in human atrial strips, before and after induction of oxidative stress induced by H2O2. Levosimendan (10(-9) to 10(-6) M) increased contractions induced by electrical stimulation (ES) in human atrial strips. The maximal positive inotropic effect of levosimendan was 145.6 +/- 4.6% of predrug values. H2O2 (10(-6) to 10(-3) M) significantly reduced contractions induced by ES. The maximum inhibition by H2O2 on the ES induced contraction was 47.2 +/- 3.5%. Levosimendan significantly increased the isometric contractions induced by ES when compared with the values obtained in the presence of 10 M H2O2 by 89.0 +/- 4.7%, 98.9 +/- 3.4%, and 111.2 +/- 3.7% at 10(-8), 10(-7), and 10(-6) M concentrations, respectively. In concentrations of 10(-7) and 10(-6) M levosimendan, the maximum responses to ES increased when compared with the values obtained in the presence of 10(-3) M H2O2 by 87.1 +/- 3.6% and 95.1 +/- 5.3%, respectively. The cumulatively applied H2O2 (10(-6)-10(-3) M) did not change the positive inotropic response to levosimendan. In conclusion, levosimendan reverses the myocardial dysfunction induced by oxidative stress in human right atrial strips. Levosimendan prevents myocardial dysfunction if administered before oxidative stress.     

Validity study of the Turkish version of the barriers to insulin treatment questionnaire

International Journal of Diabetes in Developing Countries - The purpose of this study is to test the validity and reliability of the Barriers to Insulin Treatment Questionnaire and adapt the...     

Ki-67 immunostaining in node-negative stage I/II breast carcinoma. Significant correlation with prognosis.

Prognostic predictors for node-negative breast carcinoma have not been clearly established. Immunostaining with Ki-67 antibody was performed on frozen sections of histologically proved node-negative breast carcinomas from 42 patients to examine its prognostic value and its association with other clinicopathologic and biochemical parameters, i.e., patient age and tumor size, histologic type, nuclear grade, mitotic rate, presence of vascular or lymphatic invasion, DNA ploidy, percentage of cells in S-phase, estrogen content, and c-erbB-2 amplification. Thirty-seven of the 42 tumors showed immunoreactivity with Ki-67 antibody in 1% to 55% of the tumor cells. A strongly significant correlation was observed between Ki-67 staining percentage and, respectively, nuclear grade, age, and mitotic rate. Nuclear grade 1 (the most anaplastic) tumors showed a significantly higher median percentage of cells stained (median, 14; range, 3 to 40) compared with nuclear grade 3 tumors (median, 0.5; range, 0 to 8). Thirteen patients developed recurrence; six of them died of disease. On univariate analysis, both 5-year disease-free and overall survivals were strongly associated with percentage of cells stained with Ki-67 antibody. Our results suggest that Ki-67 immunostaining correlates well with nuclear grade and clinical outcome in node-negative breast carcinoma. Because of small sample size analyzed in this study we were unable to do multivariate analysis. Therefore, further studies with larger number of cases are needed to determine whether tumor proliferative activity determined by Ki-67 immunostaining is an independent prognostic parameter or it merely reflects histopathologic features such as nuclear grade or mitotic activity.     

Epidermal growth factor receptor expression correlates with poor survival in patients who have breast carcinoma treated with doxorubicin-based neoadjuvant chemotherapy

BACKGROUND: To the authors' knowledge there are few data that correlate the expression of the epidermal growth factor receptor (EGFR) with the outcome of patients who have breast carcinoma and are treated with anthracycline chemotherapy. METHODS: Pretreatment tumor tissue samples were available from 82 patients who had locally advanced breast carcinoma and were treated on 2 protocols investigating neoadjuvant 5-fluorouracil, doxorubicin, and cyclophosphamide chemotherapy. Immunohistochemical staining for EGFR (diluted 1:50) was performed, and the staining results were interpreted without knowledge of outcome. RESULTS: Fourteen tumors (17%) were EGFR-positive, and 68 tumors (83%) were EGFR-negative. EGFR expression did not correlate with clinical stage (P = 0.361), HER-2/neu overexpression (P = 0.503), estrogen or progesterone receptor status (P = 0.631 and P = 0.838, respectively), nuclear grade (P = 0.448), or proliferative index (P = 0.769). Patients who had EGFR-positive tumors had a worse 5-year disease-free survival (DFS) rate (46% vs. 76%; P = 0.026) and overall survival (OS) rate (46% vs. 76%; P = 0.037) compared with patients who had EGFR-negative tumors. The pathologic complete response rate did not differ between the 2 groups (P = 0.389), although patients with EGFR-positive disease more commonly had > or = 4 positive lymph nodes after chemotherapy (64% vs. 29%; P = 0.028). EGFR expression continued to show a significant correlation with poorer DFS and OS in a Cox regression analysis model that included the presence or absence of four or more lymph nodes and EGFR status. CONCLUSIONS: EGFR expression may have prognostic significance in patients with locally advanced breast carcinoma who are treated with anthracycline chemotherapy. These data warrant further studies aimed at correlating EGFR expression and outcome in patients who have breast carcinoma treated with doxorubicin-based chemotherapy.