The effect of three different pulp capping cements on mineralization of dental pulp stem cells.

This study evaluated the osteogenic differentiation of human dental pulp stem cells in response to substances released by the pulp capping agents, Biodentine (BD), mineral trioxide aggregate (MTA) and two-paste calcium hydroxide cement (CHC), along with their physicochemical characteristics. The dimensional stability test showed that of the materials studied, only BD met the standards recommended by the International Organization for Standardization (ISO) for pulp capping materials and thus can be used safely. In the chemical tests, BD was the most stable material. In the Alizarin red S test, BD formed the higher amount of mineralized nodules in the mineralizing medium and also formed mineralized nodules in a non-mineralizing medium. BD releases substances that can significantly induce formation of the human dental pulp stem cell-mineralized extracellular matrix, with physicochemical characteristics that are more conducive to pulp repair than those of MTA and CHC.

Chemical Composition and Microhardness of Human Enamel Treated with Fluoridated Whintening Agents. A Study in Situ.

BACKGROUND: Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. OBJECTIVE: Assess in situ the effects of high-concentration hydrogen peroxide with and without fluoride on human dental enamel using the ion chromatography test (IC) and the Knoop hardness test (KHN). MATERIAL AND METHODS: Nineteen enamel specimens were prepared using third human molars. These specimens were fixed on molars of volunteers and were divided into groups: OP38-Opalescence Boost PF38%, PO37-Pola Office 37.5% and CO-Control group. For chemical analysis (n= 3), the dentin layer was removed, keeping only the enamel, which was subjected to acidic digestion by microwave radiation. It was necessary to perform sample dilutions for the elements fluorine (F), calcium (Ca) and phosphorus (P) for quantification using the IC test. The KHN (n= 5) was performed before and after the treatments. Five indentations were made, separated by 100 µm, for each specimen using a load of 25 gf for 5 seconds in the microdurometer. The data were analyzed using ANOVA with a 5% significance level. RESULTS: The OP38 group had the largest concentrations of F, Ca and P ions. The PO37 group showed the lowest concentrations of F and Ca ions. The average KHN was not significantly different between the OP38 and PO37 groups. CONCLUSION: Enamel whitened with hydrogen peroxide containing fluoride had greater concentrations of F, Ca and P ions. The presence of fluoride in the whitening agent did not influence the enamel microhardness.