Culture de dents (validation d'un modèle pour évaluation des biomatériaux)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Culture de dents (validation d'un modèle pour évaluation des biomatériaux)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Human Tooth Culture: A Study Model for Reparative Dentinogenesis and Direct Pulp Capping Materials Biocompatibility

International audienceIn a previous work, based on an in vitro entire tooth culture model of human immature third molars, we demonstrated that perivascular progenitor cells can proliferate and migrate to the injury site after pulp exposure. In this work, we investigated the differentiation of cells after direct capping with biomaterials classically used in restorative dentistry. Histological staining after direct pulp capping with Calcium Hydroxide XR 1 or MTA revealed early and progressive mineralized foci formation containing BrdU-labeled sequestered cells. The molecular characterization of the matrix and the sequestered cells by immunohistochemistry (Collagene type I, Dentin sialoprotein, and Nestin) clearly demonstrates that these areas share common characteristics of the mineralized matrix of reparative dentin formed by odontoblast-like cells. This reproduces some features of the pulp responses after applying these materials in vivo and demonstrates that the entire tooth culture model reproduces a part of the early steps of dentin regeneration in vivo. Its future development may be useful in studying the effects of biomaterials on this process

Biological properties of a neutralized 2.5% sodium hypochlorite solution

International audienceObjectives. The objective of this study was to evaluate the influence of neutralizing a 2.5% NaOCl solution on its cytotoxicity, genotoxicity, and tissue-dissolving potential.Study design. The cytotoxicity and the genotoxicity of Dakin, a 2.5% NaOCl solution, and a neutralized 2.5% NaOCl solution were assessed according to ISO 10993 standards. The weight of palatal mucosa samples placed in neutralized 2.5% NaOCl, 2.5% NaOCl was recorded over time as well as the pH of the solutions.Results. The neutralized 2.5% NaOCl solution was 10-fold more cytotoxic than the 2.5% NaOCl solution. None of the solutions was genotoxic. The 2.5% NaOCl solution had a better tissue-dissolving capacity than the neutralized 2.5% NaOCl solution. The pH of the 2.5% NaOCl solution and neutralized 2.5% NaOCl solution decreased from 12 to 9 and from 7.5 to 5.6, respectively.Conclusion. Neutralizing a 2.5% NaOCl solution increased its cytotoxicity, did not induce any genotoxic effect, and reduced its tissue-dissolving ability

Shelf life, dissolving action, and antibacterial activity of a neutralized 2.5% sodium hypochlorite solution

International audienceThe aim was to evaluate the shelf life and the dissolving and antibacterial properties of a neutralized 2.5% NaOCl solution. Study design. The loss of available chlorine and the pH of the neutralized 2.5% NaOCl solution were recorded to determine its shelf life. The dissolving action on bovine dental pulp was assessed measuring weight loss, pH variation, and decrease in available chlorine content. The antibacterial activity was evaluated on artificially infected human teeth. The roots were endodontically prepared, sterilized, and inoculated with Enterococcus faecalis before irrigation with the neutralized solution. The presence of intracanal bacteria after irrigation was recorded. Results. The neutralized solution presented a shelf life of 2 hours, dissolving capacities equivalent to control for the first 5 minutes, and a better antibacterial efficiency. Conclusion. The neutralized 2.5% NaOCl solution must be used within 2 hours after mixing, should be frequently renewed to maintain its dissolving capacities, and presented enhanced antibacterial properties