Understanding the Protective Effect of Phytate in Bone Decalcification Related-Diseases.

Myo-inositol hexaphosphate (phytate; IP6) is a natural compound that is abundant in cereals, legumes, and nuts, and it can bind to crystal surfaces and disturb crystal development, acting as crystallization inhibitor. The adsorption of such inhibitors to crystal faces can also inhibit crystal dissolution. The binding of phytate to metal cofactors suggests that it could be used for treatment of osteoporosis. Our in-vitro study showed that phytate inhibits dissolution of hydroxyapatite (HAP). The effect of phytate was similar to that of alendronate and greater than that of etidronate. This led us to perform a cross-sectional study to investigate the impact of consumption of IP6 on bone mineral density (BMD) in post-menopausal women. Our data indicate that BMD and t-score of lumbar spine increased with increasing phytate consumption, and a phytate consumption higher than 307 mg/day was associated with a normal BMD (t-score > -1). These data suggest that phytate may have a protective effect in bone decalcification by adsorbing on the surfaces of HAP, and a daily consumption of phytate-rich foods (at least one serving/day of legumes or nuts) may help to prevent or minimize bone-loss disorders, such as osteoporosis. However, further studies are needed to gain a better understanding about the mechanism of inhibition of phytate in bone-related diseases (see graphical abstract).

Therapeutic effectiveness of a new enzymatic bleaching dentifrice.

BACKGROUND: Research into bleaching focuses on new products in order to minimize undesirable effects. This study evaluated the bleaching effectiveness of a new enzymatic-activated dentifrice. MATERIALS AND METHODS: A total of 20 volunteers were bleached with a dentifrice containing 5% lactoperoxidase and 3% carbamide peroxide applied three times a day for two minutes over 21 days. Color was recorded before and after the treatment using a spectrophotometer. CIELAB differences were calculated before and after treatment using the paired t test (P < 0.05). RESULTS: Lightness was significantly higher after treatment (P < 0.001), ΔE was 5.14. The maxillary central incisors showed greater lightness than the laterals and canines, both before and after treatment, and a greater tendency towards green and blue; the same occurred in the mandibular central incisors in comparison to the canines and laterals. CONCLUSIONS: The use of brush-applied enzyme-activated carbamide peroxide at low concentrations with short exposure time is effective for whitening teeth. CLINICAL IMPLICATIONS: Enzymatic dental bleaching is able to increase the efficiency of low concentration peroxides, reducing the potential risk of peroxides on oral tissues.

The whitening effect of enzymatic bleaching on tetracycline.

OBJECTIVE: Carbamide peroxide and hydrogen peroxide have been used as tooth whitening agents. The aim of this paper was to determine the efficiency of several enzyme-containing whitening systems. A method to determine the rate of 'in vitro' tetracycline whitening was also developed. METHODS: We determined the tetracycline whitening ability of carbamide peroxide and hydrogen peroxide, and the influence of peroxidase and lactoperoxidase on this tetracycline whitening rate. RESULTS: High peroxidase and lactoperoxidase concentrations increased the rate of tetracycline decoloration obtained with carbamide peroxide or hydrogen peroxide. The decoloration rate observed was lower when the glucose/glucose oxidase system was used to generate hydrogen peroxide 'in situ'. The presence of peroxidase increased the decoloration rate of extracted teeth obtained with carbamide. CONCLUSIONS: Enzymes such as peroxidase could be used as whitening catalysts to increase the rate of tetracycline decoloration.