Effect of a newly developed hematoporphyrin derivative preparation on oral flora during orthodontic treatment

This study was designed to assess the effect of topical porphyrin application on some bacterial and fungal species of oral flora after using orthodontic treatment [ODT] which indicated to correct abnormalities of the teeth of patient. A novel porphyrin derivative was used. It was concluded that, all Gram-negative strains appeared to be resistant, except neisseria. Gram-positive strains were significantly inhibited due to porphyrin application. Oral fungus as C and ida albicans were significantly inhibited after porphyrin application

Tensile fracture of soldered and unsoldered stainless steel wires

This study was designed to investigate the effect of heating on the breaking tensile strength of soldered and unsoldered stainless steel orthodontic wires, together with micrographic photography of the etched surfaces compared to "as-received". All heated or soldered wires had fractured under stress at the area in the wire, which had been heated. No fracture occurred in the soldered portion of the wires. Photographic micrography revealed that the heated wire had undergone pitting and other structural alterations, which had caused the wire to become weak and subsequently fracture. The wires had lost their wrought strength properties when exposed to the high temperatures used in soldering and, as a result, were less able to withst and the tensile forces exerted. The clinical significance is that heat necessary for flame soldering of orthodontic wires will likely cause a significant reduction in the useful properties of that wire