Effect of bleaching agents on the flexural strength of bovine dentin.

The aim of this study was to evaluate the effect of bleaching on the flexural strength of bovine dentin, using bleaching agents containing calcium (Whiteness HP Blue and Whiteness Class) and not containing calcium (Whiteness HP and Whiteness Perfect). Sixty bovine incisor tooth slices were obtained and divided into fve experimental groups (n = 12), such as G1, untreated control group; G2, Whiteness HP Max [35% hydrogen peroxide (HP)]; G3, Whiteness HP Blue (35% HP); G4, Whiteness Class (7.5% HP) and G5, Whiteness Perfect (22% carbamide peroxide).

Colour stability, staining and roughness of silorane after prolonged chemical challenges.

Objectives: To investigate the effect of prolonged chemical challenges on colour stability, staining susceptibility, and roughness of a silorane composite material when compared to methacrylate-based composites.

Methods: Initial colour and roughness were registered for specimens fabricated from methacrylate or silorane composites. Specimens were individually stored at 37°C in 0.