Decreasing the molar feed ratio of CA/LA Epigenetics inhibitor from 1/15 to 1/128 reduced the average number of CA units embedded in the copolymer from 4 to 1. With 1/15 CA/LA, the copolymer was not a star-shaped polymer, and its weight-average molecular weight was the biggest (weight-average molecular weight = 12,700 Da, weight-average molecular weight/number-average molecular weight = 1.68). With 1/32 CA/LA, the copolymer with two CA units was not a star-shaped polymer either. With 1/64, 1/100, and 1/128 CA/LA, the copolymer mainly had one CA unit core embedded as a normal star-shaped PDLLA with four arms, and certain crystallinity could be detected. The novel direct copolycondensation method was
simple and practical for the synthesis of the asymmetrical star-shaped PDLLA material, and it was advantageous for this PDLLA material embedded in the special bioactive molecule CA to be applied in the field of drug delivery and tissue engineering. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1405-1415, 2010″
“Objective. The purpose of this study was STI571 Protein Tyrosine Kinase inhibitor to evaluate the effects of different surface treatments on the bond strength of a fiber post to dentin.
Study design. Sixty extracted human
maxillary incisor teeth were manually shaped with K-files using the step-back technique. ISO size 45 files were used as master apical files. Post spaces were prepared and then the root canals were subjected to one of the following 5 surface treatments: irrigation with 5% sodium hypochlorite (NaOCl); treatment with ethanol, ethyl acetate, and acetone-based cleansing agent (Sikko Tim); irrigation with 17% EDTA; etching with 37% orthophosphoric acid for 15 seconds; and etching with 10% citric acid for 15 seconds. Fiber posts were luted using self-etching/self-priming dual polymerized
resin cement. From the coronal part of each root, 3 slides of 0.6-mm thickness were obtained. A push-out bond strength test was performed by a universal testing machine at a crosshead speed of 0.5 mm/min. Dentin surfaces were examined under scanning electron microscopy (SEM) after different surface treatments. Data were analyzed with a one-way analysis of variance (ANOVA) and Tukey HSD test.
Results. PCI-32765 mw ANOVA revealed that canal surface treatment affected the bond strength (P < .001). The highest bond strength was obtained in the Sikko Tim group. The results also showed that surface treatment methods increased the bond strength to dentin when compared with the control group.
Conclusions. Sikko Tim group was the more effective surface treatment agent compared with EDTA, orthophosphoric acid, citric acid, and control groups; however, it could not remove the smear layer and sealer remnants effectively on radicular dentin surfaces. Removal of the smear layer and opening of dentinal tubules are not recommended when a self-etching/self-priming adhesive system is used. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108:e74-e80)”
“The effects of accelerating voltage (0.