Bleaching tetracycline-stained teeth is the most challenging form of tooth lightening. This article reports on 44 subjects who bleached their tetracycline-stained teeth for 6 months using trays with reservoirs overnight in a half-mouth designed study and 2 of 3 different concentrations of carbamide peroxide (10%, 15% or 20%). The subjects were followed for 5 years. The area evaluated was the mi...

Background: Bleaching agents have evolved in improving the appearance of discolored teeth. These agents can be hydrogen peroxide, carbamide peroxide or other proprietary material that breaks down into water and oxygen. The dissociated products penetrate through pores of enamel and dentine changing the value of the tooth. Some of the materials used in endodontics as an irrigant have mechanism of...

Thisin vitro study was conducted to evaluate the effect of tooth whitening on the surface roughness of dental restorative materials using AFM. Two hybrid resin composites and nano-ionomer were fabricated in samples with 2 mm thickness and 6 mm diameter. No changes in roughness was observed for all three materials tested after 14 days of bleaching with 20% carbamide peroxide (CP), compared to th...

The effect of bleaching on fracture toughness (Kic) of existing composite-dentin interfaces was assessed using the notchless triangular prism (NTP) specimen fracture toughness test. Human molars and premolars (<6 months old) were wet ground on 600 SiC to obtain 4x4x4x4mm triangular prisms with buccal or lingual exposed for bonding. Buccal or lingual dentin surfaces, ground on 600 grit sandpaper...