This split-arch clinical study was performed to compare the effects of using 10% carbamide peroxide bleaching agent for one hour twice a day with its use for 8 hours/night on tooth color change, color stability and sensitivity. Method: Bleaching trays, with reservoirs for the six maxillary anterior teeth, were fabricated for 12 volunteers. The trays were cut into two halves between the left and...

Silver physical developers consist of silver ions and a reducing (developing) agent. They were formulated for developing latent images on photosensitive materials such as photographic emulsions. The mechanism of how the latent image nuclei catalyze the reduction of silver ions by a reducing agent to form black colloidal silver particles has been extensively studied. These developers also happen...

AIM Light curing of resin composites may considerably change the color of resin composites. The aim of this study was to evaluate the changing pattern of resin composite's color by different curing times. MATERIALS AND METHODS Fifteen, 1 mm-thick, samples of each A2 shade Clearfill and Filtek P60 composites were prepared. First five samples were cured for 10s (400 mW/cm2) in each pole of the ...

We have studied the phase equilibria of three ceramic quasibinary systems Ti1-x Zr x N, Ti1-x Hf x N and Zr1-x Hf x N (0  ⩽  x  ⩽  1) with density functional theory, cluster expansion and Monte Carlo simulations. We predict consolute temperatures (T C), at which miscibility gaps close, for Ti1-x Zr x N to be 1400 K, for Ti1-x Hf x N to be 700 K, and below 200 K for Zr1-x Hf x N. The asymmetry o...

Shellac (SL) is a natural resin employed for wood finishing, while clove (Eugenia caryophyllata) and thyme (Satureja hortensis) essential oils (C-EO, T-EO) are organic products of vegetal origin with antifungal, antimicrobial antioxidant properties. The present paper aims at exploring the potential modifying alcoholic shellac solutions T-EO), focussing on recurrent effects this modification tra...

OBJECTIVE In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the ...

A metal-free 16-membered N4-donor [1 + 1] Schiff-base macrocycle was isolated as HL(Pr)·2acid, by 1 : 1 condensation of diphenylamine-2,2'-dicarboxaldehyde (1), dipropylene triamine and an excess of either acetic or formic acid, or as HL(Pr)·(tosylic acid) when just one equivalent of tosylic acid was employed. Interestingly, the acid-free synthesis employed for the 14-membered analogue HL(Et) f...

PURPOSE The aim of the study was to evaluate the effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations. MATERIALS AND METHODS Three different types of disk-shaped zirconia coping specimens (Lava, Cercon, Zirkonzahn: ø10 mm × 0.4 mm) were fabricated and veneered with IPS e.max Press Ceram (shade A2), for total thicknesses of 1 and ...