Shear bond strength of a new polycarbonate bracket--an in vitro study with 14 adhesives.

Shear bond strength and failure location were used to evaluate the effectiveness of plastic bracket primers for bonding diacrylate adhesives on a new fibre-reinforced polycarbonate bracket. Maxillary incisor polycarbonate and mesh-based brackets as control were bonded to human incisors with 14 different adhesives (four filled diacrylate two-paste, six diacrylate one-step and four power-liquid acrylic adhesives), and after thermo-cycling for 2000 cycles between 5 degrees and 55 degrees C, tested in shear. A non-parametric test (Mann-Whitney U test) was used to compare the shear bond strength of the polycarbonate brackets with the mesh based brackets and a One-way test (according to Scheffe) to compare the shear bond strength of different adhesives.

[The shearing strength of titanium brackets depending on the coating procedure].

It has long been recognized that corrosion of the metal alloys used in the different fields of dentistry can cause intra-oral problems such as allergic reactions. Titanium, a metal all but impervious to corrosion, presents an alternative to the metal alloys used in the fabrication of orthodontic brackets. The purpose of this study was to test the bonding strength between titanium brackets treated with 5 different opaque and non-opaque coatings and a 2-phase adhesive.

Posture of the head, the hyoid bone, and the tongue in children with and without enlarged tonsils.

The purpose of this investigation was to analyse whether there were any differences between children with and without enlarged tonsils with regard to the posture of the head, the hyoid bone, and the tongue. Twenty-two children with enlarged tonsils were compared with a matched normal control group. Of the children in the tonsil group, 59 per cent were mouth-breathers during the day and 82 per cent during the night.

Cranio-facial morphology in children with and without enlarged tonsils.

The purpose of the present study was to compare the cranio-facial morphology in children with and without enlarged tonsils. The material consisted of 73 children with enlarged tonsils, and a control group of children with normal tonsils, matched for age, sex, and number. The mean age for the groups was 10.