In vitro fluoride uptake by bovine enamel in using cyanoacrylate adhesives containing fluoride compounds

To study thein vitro uptake of fluoride from 3-year-old bovine enamel, enamel biopsies for fluoride analysis were performed using five successive etchings. At 10 µm etch depth the uptake of fluoride was maximum for all methyl--cyanoacrylates containing six kinds of fluoride compounds. The fluoride concentration was pronounced by 1 month of immersion, rather than by 1 week of immersion in distilled water. In particular, fluoride compounds such as BiF₃, NaF, SnF₂ and ZnF₂ had a significant difference (p<0.01) from KF and Na₂FPO₄ at 1 month of immersion.     

Characterization of Ba0.55Sr0.45TiO3 films as light and temperature sensors and its implementation on automatic drying system model

The growth of Ba_0.55Sr_0.45TiO₃ films on p-type silicon substrate with depletion and enhancement treatments have been conducted in this research. The aims were to examine film sensitivity as light sensor and value range, resolution, acuracy level, and their hysteresis as temperature sensor. The films were annealed at 800, 850, and 900 °C for 15 hours. In this work, enhancement BST of 850 °C was the best quality film and utilized as light and temperature sensors. Its implementation has been successfully conducted on ATMega8535 microcontroller-based automatic drying system model by exploiting the working principle of the BST films as automatic switch.     

A fundamental study of fissure sealant in dental application:in vitro adhesive tensile strength

In order to develop the sealing of pits and fissures in human enamel, a polymethylmethacrylate (PMMA) cylinder was bonded to a flattened one and to the labial enamel surface of young bovine teeth subjected to acid-etched treatment. An increase in adhesive tensile strength occurred for methyl--cyanoacrylate, one of the alkyl-cyanoacrylate adhesives tested. A larger significant difference in the release of fluoride was found in each cyanoacrylate adhesive containing 11 kinds of fluoride compounds. The value of the adhesive tensile strength at the interface of the PMMA-acid-etched bovine enamel depended on the cyanoacrylate adhesive type and the conservation conditions.     

A caries prophylactic study on artificial lesions in bovine tooth enamel coated with cyanoacrylate adhesives containing fluoride compounds

Enamel lesions produced by a buffered solution have been examined, by means of a polarized-light microscope, for abrased bovine tooth enamel coated with methyl--cyanoacrylates containing six kinds of fluoride compounds. The white-spot lesion of the demineralization area was found for all bovine tooth enamels, such as a control specimen coated with only methyl--cyanoacrylate without a fluoride compound and those with cyanoacrylates containing fluoride compounds, but both polarizing microscopy and the calcium solubility showed a difference in the demineralization area and in the amount of dissolved calcium among the bovine tooth enamels. Of the cyanoacrylates investigated, three cyanoacrylates containing NaF, SnF₂ and ZnF₂ as the fluoride compound were effective in the formation of a thin demineralization area which reduced white-spot lesion.