Souza M D B, Pessan J P, Lodi C S, Souza J A S, Camargo E R, Souza Neto F N, Delbem A C B
1 School of Dentistry, UNIOESTE-Universidade Estadual do Oeste do Paraná, and Rua Universitária, Cascavel, Brazil.
2 Department of Pediatric Dentistry and Public Health, School of Dentistry, São Paulo State University (UNESP), Araçatuba, Brazil.
JDR Clin Trans Res. 2017 Jul;2(3):233-240. doi: 10.1177/2380084416683913. Epub 2016 Dec 21.
This double-blind crossover study assessed the effects of a low-fluoride (low-F) dentifrice containing nanosized sodium trimetaphosphate (TMP) on enamel demineralization in situ. Nineteen subjects wore palatal appliances containing 4 blocks of bovine enamel and were randomly assigned to brush their teeth with placebo (without F/TMP), 250-ppm F (250F), 250F plus 0.05% nanosized TMP (250F-TMPnano), and 1,100-ppm F (1,100F) dentifrices during 7 d, under cariogenic challenge. Enamel surface hardness and cross-sectional hardness (ΔKHN [Knoop hardness number]), as well as F, calcium (Ca), and phosphorus (P) concentrations, were determined. Also, biofilm that formed on the blocks was analyzed for F, Ca, P, and insoluble extracellular polysaccharide concentrations. Data were submitted to analysis-of-variance models and Student-Newman-Keuls test ( P < 0.05). The 250F-TMPnano dentifrice promoted the lowest ΔKHN among all groups ( P < 0.001), while the percentage of surface hardness loss was similar to 1,100F. Also, similar F, Ca, and P concentrations in enamel were observed for 1,100F and 250F-TMPnano. In the biofilm, the highest F content was observed for 1,100F; Ca content was similar between 1,100F and 250F-TMPnano; and P content was similar among all groups. Similar extracellular polysaccharide values were observed for 250F-TMPnano and 1,100F ( P < 0.001), ionic activity of CaHPO, CaF, and HF ( P < 0.05) and degree of saturation of hydroxyapatite and CaF ( P < 0.05). It was concluded that the protective effect of 250F-TMPnano dentifrice was similar to a conventional dentifrice for most of the variables studied, having a more pronounced effect on the subsurface lesion when compared with the conventional toothpaste (1,100F). Knowledge Transfer Statement: Although toothpastes containing ≥1,000-ppm fluoride are more effective than low-fluoride formulations against dental caries, their early use can lead to side effects. This has prompted intensive research on alternatives to increase the anticaries effect of low-fluoride toothpastes. The present in situ study demonstrated that the addition of sodium trimetaphosphate nanoparticles to toothpastes containing 250-ppm fluoride significantly enhances the protective effect of this formulation against enamel demineralization to levels comparable to a 1,100-ppm fluoride toothpaste in terms of most of the variables studied. Most important, this formulation promoted the lowest loss of subsurface hardness among all groups, suggesting that caries lesions would take longer to develop under clinical conditions when compared with a conventional (1,100-fluoride) toothpaste.
这项双盲交叉研究评估了一种含有纳米级三聚偏磷酸钠（TMP）的低氟牙膏对牙釉质原位脱矿的影响。19名受试者佩戴含有4块牛牙釉质的腭部矫治器，并被随机分配在致龋挑战下，分别使用安慰剂（不含氟/TMP）、250 ppm氟（250F）、250F加0.05%纳米级TMP（250F-TMPnano）和1100 ppm氟（1100F）牙膏刷牙7天。测定了牙釉质表面硬度和横截面硬度（ΔKHN[努氏硬度值]），以及氟、钙（Ca）和磷（P）浓度。此外，还分析了矫治器上形成的生物膜中的氟、钙、磷和不溶性细胞外多糖浓度。数据采用方差分析模型和Student-Newman-Keuls检验（P<0.05）。在所有组中，250F-TMPnano牙膏导致的ΔKHN最低（P<0.001），而表面硬度损失百分比与1100F相似。此外，1100F和250F-TMPnano的牙釉质中氟、钙和磷浓度相似。在生物膜中，1100F的氟含量最高；1100F和250F-TMPnano的钙含量相似；所有组的磷含量相似。250F-TMPnano和1100F的细胞外多糖值相似（P<0.001），磷酸氢钙、氟化钙和氟化氢的离子活性（P<0.05）以及羟基磷灰石和氟化钙的饱和度（P<0.05）也相似。得出的结论是，对于大多数研究变量，250F-TMPnano牙膏的保护作用与传统牙膏相似，与传统牙膏（1100F）相比，其对牙釉质表层下病变的影响更为显著。知识转移声明：虽然含氟量≥1000 ppm的牙膏在预防龋齿方面比低氟配方更有效，但其早期使用可能会导致副作用。这促使人们对提高低氟牙膏防龋效果的替代品进行深入研究。本原位研究表明，在含250 ppm氟的牙膏中添加纳米级三聚偏磷酸钠，在大多数研究变量方面，可显著增强该配方对牙釉质脱矿的保护作用，使其达到与含1100 ppm氟牙膏相当的水平。最重要的是，该配方在所有组中导致的表层下硬度损失最低，这表明与传统（含1100 ppm氟）牙膏相比，在临床条件下龋损发展所需时间更长。
