São Paulo State University (Unesp), School of Dentistry, Araçatuba, Department of Pediatric Dentistry and Public Health, Rua José Bonifácio 1193 Araçatuba, SP, Cep 16015-050, Brazil.
Federal University of São Carlos (UFSCar), LIEC-Department of Chemistry, Rodovia Washington Luís, s/n São Carlos, SP, Cep 13565-905, Brazil.
Arch Oral Biol. 2018 Jun;90:108-112. doi: 10.1016/j.archoralbio.2018.03.008. Epub 2018 Mar 20.
This study evaluated the capacity of sodium hexametaphosphate (HMP) at different concentrations to alter the surface properties of dental enamel in order to increase calcium and phosphate adsorption.
Bovine enamel blocks (4 mm × 4 mm, n = 144, 12/group) were divided: 0%; 0.25%; 0.5%; and 1% HMP, followed or not by application of solutions containing Ca or Ca-PO, totaling 12 groups. The treatments were performed for 2 min, and the surface free energy (mN/m) was calculated by measuring the contact angles of three probing liquids (deionized water, diiodomethane and ethylene glycol), which was used to determine the polar and nonpolar components of the enamel surface. Calcium (Ca), phosphate (PO) and HMP in the solutions treatment solutions were analyzed before and after treatment. The data presented normal and homogeneous distribution and then were subjected to ANOVA, followed by Student-Newman Keuls' test (p < 0.05).
The higher the% of HMP in the solutions, the greater HMP adsorption and more electron-donor sites on enamel surface were achieved (p < 0.05). Also, Ca adsorption was higher with increasing% HMP in the solutions (p < 0.05), which in turn reduced electron-donor sites on enamel surface. Increased Ca and PO adsorption occurred at 0.5% and 1% HMP after treatment with Ca-PO solution, resulting in a less electron-donor sites on surface when compared to the other treatments (P < 0.05).
HMP leads to a more electron-donor sites on enamel surface, what promotes greater adsorption of Ca and PO ions.
本研究评估了六偏磷酸钠（HMP）在不同浓度下改变牙釉质表面性质以增加钙和磷酸盐吸附的能力。
将牛牙釉质块（4mm×4mm，n=144，每组 12 个）分为 0%、0.25%、0.5%和 1%HMP 组，随后应用或不应用含有 Ca 或 Ca-PO 的溶液，共 12 组。处理持续 2 分钟，通过测量三种探针液体（去离子水、二碘甲烷和乙二醇）的接触角来计算表面自由能（mN/m），用于确定牙釉质表面的极性和非极性成分。处理前后分析处理溶液中的 Ca、PO 和 HMP。所呈现的数据呈正态和均匀分布，然后进行方差分析，随后进行 Student-Newman Keuls 检验（p<0.05）。
溶液中 HMP%越高，牙釉质表面的 HMP 吸附量越大，电子供体位点越多（p<0.05）。随着溶液中 HMP%的增加，Ca 吸附量也增加（p<0.05），这反过来又减少了牙釉质表面的电子供体位点。在用 Ca-PO 溶液处理后，0.5%和 1%HMP 溶液中 Ca 和 PO 的吸附增加，与其他处理相比，表面的电子供体位点减少（P<0.05）。
HMP 导致牙釉质表面有更多的电子供体位点，从而促进了更多的 Ca 和 PO 离子的吸附。
