We propose a network rebonding model for light-induced metastability in amorphous silicon, involving bonding rearrangements of silicon and hydrogen atoms. Nonradiative recombination breaks weak silicon bonds and generates dangling bond-floating bond pairs, with very low activation energies. The transient floating bonds annihilate, generating local hydrogen motion. Charged defects are also found...

After 20 months of clinical testing and more than 600 bonded arches, brief interim conclusions can be drawn on treatment with a new lingual bracket system, one that differs fundamentally from conventional appliances in both design and manufacture. The demand for maximum individuality is met by using state-of-the-art computer-aided design/computer-aided manufacturing technology to fuse the 2 nor...

The aim of the study was to examine, in vitro, the effect of a vertical force on the debond force and deformation of two multi-stranded wires bonded to the lingual enamel of lower incisor teeth. Two different stainless steel wires were used, 0.016 × 0.022 inch (Bond-A-Braid® Reliance Orthodontic Products) and a three-stranded 0.0175 inch wire (Ortho Technology). An in vitro model was used to si...