The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction...

The biobleaching efficiency of xylanase and laccase enzymes was studied on kraft pulps from wood and nonwood based raw materials employed in the Indian paper industry. Treatment of these pulps with xylanase enzyme could result in improved properties, showing 2.0% ISO gain in pulp brightness and/or reducing the demand of chlorine-based bleach chemicals by up to 15% with simultaneous reduction of...

Introduction: Cervical root resorption is one of the most important complications of intra coronal bleaching. A way of preventing this type of resorption is using a coronal barrier under the bleaching materials. The aim of this study was to compare the sealing ability of glass ionomer cement and Pro Root Mineral Trioxide Aggregate (MTA) as a coronal barrier in intra coronal bleaching. Materi...

background: the purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (esthet•x hd, clearfi l ap-x, gradia direct) and fi ve nanohybrid composite resins (ceram•x, gc kalore, g-aenial, grandio, grandioso), after staining and bleaching procedures. materials and methods: the composite resins were polymerized with a curing light (celalux ii, voco...

OBJECTIVES The present study aimed to investigate the effect of staining solutions on microhardness and shade changes of a nanofilled resin composite, which had been previously in contact with bleaching agents. MATERIALS AND METHODS A total of 135 disk-shaped specimens (10 mm × 2 mm) were fabricated with a nanofilled resin (Filtek Supreme) and photocured with a Light Emission Diode (LED) unit...

This study clinically evaluated the alteration of color, color stability, dental sensitivity and gingival irritation on patients undergoing dental bleaching using varying bleaching methods and light-activation sources. According to pre-established criteria, 40 patients were selected and randomly divided into four groups (n=10): Group 1--35% Hydrogen Peroxide (HP); Group 2--35% HP plus Halogen C...

Background. Dentists' awareness of the effects of bleaching agents on the surface and mechanical properties of restorative materials is of utmost importance. Therefore, this in vitro study was undertaken to investigate the effects of different bleaching strategies on the microhardness of a silorane-based composite resin. Methods. Eighty samples of a silorane-based composite resin (measuring 4 m...

The purpose of this study was to compare two in-office bleaching methods with respect to tooth color change and level of hydrogen peroxide penetration into the pulp cavity and to evaluate relationships between penetration level and color change. Eighty extracted canines were exposed to two different bleaching regimens (conventional vs sealed bleaching technique). After exposure to 38% hydrogen ...

The present study compares the efficacy of various disinfectants against Bacillus anthracis spores. While Bleach Rite(®) and 10% bleach reduce spore numbers by 90% within 10 minutes, a long contact time is required for complete disinfection. By contrast, although SporGon(®) did not initially reduce the number of spores as quickly as Bleach Rite or 10% bleach, shorter contact times were required...