PubMed · 9462135
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
T G Wichgers, R L Emert. 1997. Dentin hypersensitivity.. https://pubmed.ncbi.nlm.nih.gov/9462135/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The effect of Sensodyne dentifrice, which contains strontium chloride hexahydrate, on the occlusion of dentinal tubules was studied in vivo and in vitro. Eight premolar teeth scheduled for extraction for orthodontic purposes were used. Four of the teeth were extracted before Sensodyne application (in vitro). The other four teeth were treated in vivo and then extracted. A patch of enamel was removed from all the teeth to expose the dentinal surfaces, and the smear layer over the exposed area was removed. In the in vivo test, the patients were instructed to brush their teeth for 1 minute, twice a day, for 2 weeks. The teeth were then extracted and kept in distilled water until examined by scanning electron microscope. The in vitro teeth were brushed in the same manner and kept in distilled water between brushings. Most of the in vitro dentinal tubules were found to be open, whereas most of the in vivo dentinal tubules were occluded.
Toothbrush bristles with sharp edges have been postulated to represent a greater threat to dental tissues than end-rounded bristles. This study evaluated the effect of both in vivo and laboratory use on bristle wear rate, tip geometry and in vitro abrasivity. Three soft manual brushes (Oral-B P40, Crest Complete and Butler GUM) and one powered brush (Rota-dent) were tested. The results of this study show that the wear rate varied directly with brushing load and amount of dentifrice, and inversely with bristle diameter. Despite the initial geometry, a flat tip with rounded rims was typically observed after only 30 minutes of manual or Rota-dent brush use. There was no statistical difference in in vitro abrasion for new brushes versus used brushes.
The method is based upon the reaction between fluoride ions and the coloured complex of Fe(III) with methyl salicylate to form the stable, colourless hexaflouride complex of iron. The conditions of the method (pH, time and combination ratio) were studied and a standard curve was obtained for 0.01-0.08 mg NaF ml-1, at 525 nm. A study was conducted on interference with complexing anions of Fe(III), cations that react with fluoride ions and with common ingredients of dosage forms and dental preparations. The method was validated and the results showed good precision (100.16 +/- = 2.33%) comparable with that of other analytical methods. Good results were obtained in the spectrophotometric determination of fluoride ions in a stomatological gel and in a toothpaste.