Carbon foams as catalyst supports for phenol photodegradation.

A carbon foam using coal tar pitch as precursor was prepared and investigated as support for titanium oxide for the photocatalytic degradation of phenol. The performance of the carbon foam/titania composite was compared to those of unsupported titania and other activated carbon composites from the literature. The photodegradation rate of phenol over the catalysts under UV illumination was fitted to the Langmuir-Hinshelwood model; data showed that the apparent rate constant of the carbon foam supported titania was almost three times larger than that of bare titania, and comparable to that of other carbon supported composites. Considering the low porous features of the carbon foam, this suggests that large surface area supports are not essential to achieve high degradation rates and efficiencies. Moreover, when titania is supported on the carbon foam large amounts of catechol are detected in solution after UV irradiation, indicating a better degradation efficiency.

Esthetic and functional treatment of a fused permanent tooth: a case report.

This report describes a young patient with fusion of a maxillary central incisor to a supernumerary tooth. Treatment involved extraction of the fused tooth and orthodontic movement of the lateral incisor to occupy the position of the extracted tooth. A resin composite laminate veneer was placed on the lateral incisor to simulate the appearance of a central incisor. Five years of follow-up revealed that treatment had successfully restored esthetics and function.