Piracicaba Dental School, UNICAMP, Piracicaba, Brazil.
Federal University of Bahia, Salvador, Brazil.
Caries Res. 2018;52(4):323-330. doi: 10.1159/000486427. Epub 2018 Feb 14.
Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone.
由于对于淀粉是否会增加蔗糖的致龋潜力尚无共识，我们使用经过验证的 3 种物种生物膜模型来评估淀粉与蔗糖结合是否比单独使用蔗糖更能引起根牙本质脱矿。在每天暴露 8 次的情况下，将由变形链球菌（最具致龋性的细菌）、内氏放线菌（具有淀粉分解活性）和戈登链球菌（可结合唾液淀粉酶）组成的生物膜（n = 18）形成在根牙本质片上，暴露于以下一种处理方法：0.9%NaCl、1%淀粉、10%蔗糖或 1%淀粉和 10%蔗糖的混合物。在每次处理之前，生物膜都用人全唾液预处理 1 分钟。每天测量培养基的 pH 值以指示生物膜产酸。生长 96 小时后，收集生物膜，分析生物量、细菌活力和多糖。通过表面硬度损失（% SHL）评估牙本质脱矿。使用共聚焦激光扫描显微镜分析生物膜生物结构。与单独使用蔗糖相比，淀粉和蔗糖混合物的处理引起更高的（p = 0.01）牙本质脱矿（% SHL = 53.2 ± 7.0 对 43.2 ± 8.7）。这得到了以下支持：与蔗糖相比，每天暴露于淀粉和蔗糖混合物后培养基的 pH 值（p = 0.007）更低（4.89 ± 0.29 对 5.19 ± 0.32）。用淀粉和蔗糖混合物和单独用蔗糖处理的生物膜之间的微生物学和生物化学发现没有差异（p > 0.05）。我们的发现支持这样一种假设，即淀粉和蔗糖的混合物比单独使用蔗糖对根牙本质更具致龋性。
