Effect of Fluoride Toothpaste Containing Nano-Sized Sodium Hexametaphosphate on Enamel Remineralization: An in situ Study.

OBJECTIVE: To evaluate the remineralizing potential of a conventional toothpaste (1,100 ppm F) supplemented with nano-sized sodium hexametaphosphate (HMPnano) in artificial caries lesions in situ. DESIGN: This double-blinded crossed study was performed in 4 phases of 3 days each. Twelve subjects used palatal appliances containing 4 bovine enamel blocks with artificial caries lesions. Volunteers were randomly assigned into the following treatment groups: no F/HMP/HMPnano (Placebo); 1,100 ppm F (1100F); 1100F plus 0.5% micrometric HMP (1100F/HMP) and 1100F plus 0.5% nano-sized HMP (1100F/HMPnano). Volunteers were instructed to brush their natural teeth with the palatal appliances in the mouth for 1 min (3 times/day), so that blocks were treated with natural slurries of toothpastes. After each phase, surface hardness post-remineralization (SH2), integrated recovery of subsurface hardness (ΔIHR), integrated mineral recovery (ΔIMR) and enamel F concentration were determined. Data were submitted to analysis of variance and Student-Newman-Keuls' test (p < 0.001). RESULTS: Enamel surface became 42% harder when treated with 1100F/HMPnano in comparison with 1100F (p < 0.001). Treatment with 1100F/HMP and 1100F/HMPnano promoted an increase of ∼23 and ∼87%, respectively, in ΔIHR when compared to 1100F (p < 0.001). In addition, ΔIMR for the 1100F/HMPnano was ∼75 and ∼33% higher when compared to 1100F and 1100F/HMP respectively (p < 0.001). Enamel F uptake was similar among all groups except for the placebo (p < 0.001). CONCLUSION: The addition of 0.5% HMPnano to a conventional fluoride toothpaste was able to promote an additional remineralizing effect of artificial caries lesions.

Engineered GH11 xylanases from Orpinomyces sp. PC-2 improve techno-functional properties of bread dough.

BACKGROUND: Endo-1,4-ß-xylanases have marked hydrolytic activity towards arabinoxylans. Xylanases (xynA) produced by the anaerobic fungus Orpinomyces sp. strain PC-2 have been shown to be superior in specific activity, which strongly suggests their applicability in the bakery industry for the processing of whole-wheat flour containing xylans. In the present study, two xylanases from this source, the small wild-type xylanase SWT and the small mutant xylanase SM2 (V108A, A199T), were expressed in Escherichia coli, purified, characterized, tested for their ability to hydrolyze whole-wheat flour and applied in dough processing. RESULTS: Both purified SM2 and SWT showed high specific activity against oat spelt xylan and wheat arabinoxylan, exhibiting maximum activity at pH 3-7 and 60 °C. SM2 was more thermostable than SWT, which suggests that the mutations enhanced its stability. Both SWT and SM2 were able to hydrolyze whole-wheat flour, and evaluation of their applicability in dough processing by the sponge method indicated that use of these enzymes increased dough volume by 60% and reduced texture hardness by more than 50%, while gumminess and chewiness were reduced by 40%. CONCLUSION: The recombinant xylanases showed potential for application in bakery processing and can improve techno-functional properties in sponges. © 2018 Society of Chemical Industry.

In vitro effect of sodium trimetaphosphate additives to conventional toothpastes on enamel demineralization.

OBJECTIVE: The aim of this study was to evaluate the ability of conventional toothpastes (1100 ppm F) supplemented with sodium trimetaphosphate (TMP) in demineralization. MATERIAL AND METHODS: Blocks of enamel were selected and then divided into seven experimental groups of 12: toothpaste without F and TMP (placebo), toothpaste with 1100 ppm F (1100), and toothpaste with 1100 ppm F supplemented with TMP-1 % (1100 1 % TMP), 3 % (1100 3 % TMP), 4.5 % (1100 4.5 % TMP), 6 % (1100 6 % TMP), and 9 % (1100 9 % TMP). Blocks were subjected to five pH cycles (demineralizing/remineralizing solutions) at 37 °C and treated with toothpaste slurries twice daily, after which the blocks were maintained for 2 days in fresh remineralizing solution. Following treatments, surface hardness (SHf) and cross-sectional hardness were determined for calculating the integrated loss of subsurface hardness (ΔKHN). The fluoride present in the enamel was also measured. RESULTS: The SHf and ΔKHN measurements showed that supplementation with 3 % TMP was the most effective (p < 0.001) and showed greater concentration of F in the enamel (p < 0.001). CONCLUSION: Addition of 3 % TMP to a conventional toothpaste (1100 ppm F) showed greater efficacy in reducing enamel demineralization. CLINICAL RELEVANCE: Fluoride toothpastes containing trimetaphosphate possess good anticaries potential required to reduce the prevalence of dental caries in high-risk patients.

Estudo comparativo dos métodos tradicional e rápido de avaliação de procedimento de higienização, usando clorexidina como sanitizante, em indústrias de laticínios / Comparative study of traditional methods and rapid evaluation procedure for cleaning, using chlorhexidine as a sanitizer in the dairying

O presente trabalho teve o objetivo de estudar comparativamente os métodos tradicional e rápido utilizados na avaliação da eficiência de procedimentos de higienização usando clorexidina como sanitizante em uma superfície característica de uma indústria de laticínios. Para isso, utilizou-se uma máquina produtora de sorvete, na qual a superfície avaliada é constituída de aço-inoxidável ANSI 316. Após a utilização do equipamento, foi realizado o procedimento de limpeza seguido de sanitização com solução de digluconato de clorexidina a 100mg.L-1. A avaliação do procedimento foi realizada pelo método tradicional de contagem padrão em placas para enumeração de mesófilos aeróbios.(...) Os resultados encontrados indicaram não haver concordância entre os métodos quanto à classificação das condições das superfícies avaliadas, no entanto, os mesmos apresentaram correlação positiva e razoavelmente alta (0,73), indicando que o método rápido, ATP-bioluminescência, é uma ferramenta útil na avaliação de procedimentos de limpeza e sanitização.