Evaluation of the whitening and remineralization effects of a mixture of amorphous calcium phosphate, hydroxyapatite and tetrasodium pyrophosphate on bovine enamel / 대한구강보건학회지

OBJECTIVES: The purpose of the present study was to evaluate the whitening effect, morphological and structural changes, and remineralization of the enamel induced by 3 combined agents: amorphous calcium phosphate (ACP), hydroxyapatite (HA), and tetrasodium pyrophosphate (TSP). METHODS: The study was performed on 90 bovine enamel slabs, which were divided into the 6 groups: negative control-distilled water (Group 1); positive control-opalescence F (Group 2); 10% mixed agent (Group 3); 25% mixed agent (Group 4); 50% mixed agent (Group 5); and 100% mixed agent (Group 6). Changes in the shade of the enamel slabs were evaluated using Shade Eye-NCC. Morphological changes were assessed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) was used to determine the remineralizing effect of the three agents on enamel slabs. RESULTS: The change in shade of the enamel (ad*) was noted to increase significantly with increase in whitening frequency in all groups. The value of Δn* was significantly greater in all groups except for the negative control group (P<0.001). SEM revealed that the control group, Group 5, and Group 6 had similar morphologies. The fluorescence lesion areas in the 4 mixture-treated group were significantly smaller than those in the positive control group (P<0.001). CONCLUSIONS: These results showed that the mixture of ACP, HA, and TSP was highly effective for bovine enamel whitening and acted by inducing the remineralization of enamel. CLINICAL SIGNIFICANCE: We evaluated the applicability of a new mixture containing ACP, HA, and TSP. This mixture would be highly useful in aesthetic dentistry because of its whitening efficiency, which does not compromise the enamel's integrity.

Clinical Evaluation of Residual Tetrasodium Pyrophosphate Released from Two Different Anticalculus Flosses

The aim of this study was to compare the residual content of tetrasodium pyrophosphate released by two different anticalculus dental flosses (Reach PP(r) - entangled polypropylene floss and Reach NT(r) - texturized nylon) in the oral cavity. Ten healthy individuals (aged between 18 and 30 years) were enrolled in this randomized crossover clinical investigation. Participants received instructions on daily dental flossing and the interventions were randomly performed in 2 different groups (NT or PP) of five individuals each according to the dental flosses. Individuals were instructed to use each dental floss with a total of six slides on the two interproximal aspects of target teeth (3 slides on each interproximal aspect). A washout period of one week was used before start flossing interventions and after each type of dental floss to prevent any bias related to the exposure to any product that contained the active ingredient. Samples were collected by #35 sterilized absorbent paper points from interdental fluid after flossing and assessed by ion chromatography. The levels of residual tetrasodium pyrophosphate were evaluated by means of binomial generalized linear model proportions and canonical link function. Both dental flosses were effective in tetrasodium pyrophosphate release at therapeutic levels in the interdental gingival crevicular fluid for a period of up to 2 h after use. No significant differences were found between both groups (p>0.05). It may be concluded that both material composition and physical structure of the new dental floss did not affect the release or the maintenance of anticalculus agent at therapeutic levels for a period of up to 2 h after single use.

O objetivo deste estudo foi comparar o teor residual de pirofosfato de tetrasodio liberado por dois tipos diferentes de fio dental anti-cálculo (Reach PP(r) - polipropileno entrelaçado e Reach NT(r) - nylon texturizado) na cavidade oral. Dez indivíduos saudáveis (com idade entre 18 e 30 anos) foram selecionados para este estudo clínico em modelo crossover. Os participantes receberam instruções sobre como utilizarem os fios dentais e as intervenções foram randomicamente realizadas em 2 grupos de 5 participantes de acordo com o tipo de fio avaliado. O participantes foram instruídos a passarem cada fio dental em um total de 6 passadas ao redor dos 2 espaços interproximais dos dentes selecionados (3 passadas em cada face interproximal). Um período de washout de 1 semana foi utilizado antes do início do estudo e após cada intervenção com o objetivo de prevenir a ocorrência de viés relacionado à exposição de algum agente terapêutico. Amostras do fluido interdental após as intervenções foram avaliadas por meio de cromatografia de íons. A porcentagem residual de pirofosfato tetrassódico foi verificada empregando-se o método da cromatografia de íons, pela colheita do fluido interdental com cones de papel absorvente esterilizados. Os teores de pirofosfato tetrassódico residual foram comparados para cada fio dental e para cada tempo de colheita do fluido interdental. Não foram observadas diferenças significantes entre os grupos avaliados (p>0,05). Conclui-se que a composição do material e a estrutura física dos fios dentais não exerceram influência na liberação e na permanência do agente anti-tártaro, que permaneceu em níveis terapêuticos por um período de até 2 h após o uso único.

Acute Oral or Dermal and Repeated Dose 90-Day Oral Toxicity of Tetrasodium Pyrophosphate in Spraque Dawley (SD) Rats

OBJECTIVES: Tetrasodium pyrophosphate (TSP) is used in processed meat products, as an emulsifier in cheese, and as a color preservative in soybean paste. However, little is known about its toxicity. This study was conducted to investigate the potential acute and repeated dose toxicity of TSP in Spraque Dawley (SD) rats. METHODS: In the acute study, animals were administered with oral or dermal doses of 2,000 mg/kg TSP. In the repeated dose study, animals were administered doses of 0, 250, 500, and 1,000 mg/kg by oral gavage five times a week for 90 days. RESULTS: In acute toxicity studies, no dead animals or abnormal necropsy findings were found in the control or treated group. In the repeated dose toxicity study, there were no significant changes in body weight in the 1,000 mg/kg treatment group, or food consumption, urinalysis, and hematology in any group. With regards serum biochemistry, the levels of total protein, albumin, A/G ratio, triglyceride, calcium and inorganic phosphate were altered at doses of 500 and 1,000 mg/kg. However, no changes were observed at the dose of 250 mg/kg. With regards histopathological findings, cortical tubular basophilia of the kidney increased at the dose of 1,000 mg/kg, but not at doses of 250 and 500 mg/kg. No significant changes were observed in other organs at doses of 250, 500, and 1,000 mg/kg. CONCLUSIONS: Based on the results, TSP is unclassified according to the Globally Harmonization System, with an LD50 value of over 2,000 mg/kg. The no observed effect level (NOEL) and no observed adverse effect level (NOAEL) were 250 and 500 mg/kg /day respectively and the target organ appears to be the kidney.