Development of mouthwash with Rosmarinus officinalis extract

Rosmarinus officinalis, which belongs to the Lamiaceaefamily, is a species of medicinal flora with therapeutic properties. In order to exploit the benefits of these properties, a mouthwash formulation was developed, with careful selection of raw materials to meet pharmacotechnical requirements. Extracts of the plant were incorporated into a mouthwash, which was shown to have inhibitory action in vitro against the micro-organisms commonly found in periodontics. Controls for assessing the quality of the drugs were carried out, quantifying phenols and flavonoids as chemical markers. Mouthwash solutions were formulated containing 0.1, 5 and 10% ethanol extract of R. officinalis; and 0.05, 5 and 10% of the hexane fraction of R. officinalis. In order to evaluate synergism, ethanol extract and hexane fraction were also added to formulations containing 0.05% sodium fluoride and 0.12% chlorhexidine digluconate. These formulations were assessed for inhibitory effect against the specific microorganisms involved in the process of bacterial plaque formation, S. mutans(ATCC25175) and C. albicans(ATCC 10231), frequently found in cases of oral infections. The agar diffusion method was used to evaluate the inhibitory activity of extracts and formulations. All mouthwash solutions displayed inhibitory activity having higher sensitivity to S. mutansfor the 5% ethanol extract+0.05% sodium fluoride, and greater sensitivity to C. albicansfor the 10% hexane fraction. Results were characterized by the appearance of a growth inhibition halo, justifying the utilization and association of extracts of R. officinalis

Demineralized dentin 3 D porosity and pore size distribution using mercury porosimetry

ObjectivesThe objectives of this study were to assess demineralized dentin porosity and quantify the different porous features distribution within the material using mercury intrusion porosimetry (MIP) technique. We compared hexamethyldisilazane (HMDS) drying and lyophilization (LYO) (freeze-drying) in sample preparation.MethodsFifty-six dentin discs were assigned into three groups. The control (CTR) group discs were superficially acid-etched (15 s 37% H3PO4) to remove the smear layer and then freeze-dried whereas LYO and HMDS groups samples were first totally demineralized using EDTA 0.5 M and then freeze-dried and HMDS-dried respectively. MIP was used to determine open porosity and pore size distribution of each pair of samples. Field emission scanning electron microscopy (FESEM) was used to illustrate the results.ResultsThe results showed two types of pores corresponding either to tubules and micro-branches or to inter-fibrillar spaces created by demineralization. Global porosity varied from 59% (HMDS-dried samples) to 70% (freeze-dried samples). Lyophilization drying technique seems to lead to less shrinkage than HMDS drying. FESEM revealed that collagen fibers of demineralized lyophilized samples are less melted together than in the HMDS-dried samples.SignificanceDemineralized dentin porosity is a key parameter in dentin bonding that will influence the hybrid layer quality. Its characterization could be helpful to improve the monomers infiltration

Microfluidic model of porous media wetting ; application to a collagen network

International audienc

Three-dimensional pore-scale modelling of dentinal infiltration

International audienc

In vitro and in silico study of cell growth in porous scaffold under dynamic flow

International audienceThe use of bioreactors for cultivating bone-forming cells on a three-dimensional porous scaffold material resolves mass transport limitations and provides physical stimuli, increasing the overall proliferation and differentiation of cells. Despite the recent and significant development of bioreactors for tissue engineering, the underlying mechanisms leading to improved bone substitutes remain mostly unknown. Previous studies have shown that numerical simulations can be a powerful tool to predict tissue development in complex environments. However, current models often present a poor representation of local physics and comparisons with experiments generally do not lead to a quantitative agreement. In order to experimentally reproduce the fluid flow through a porous scaffold, three-dimensional, micro-architectured micro-fluidic chambers have been designed. Osteoblast cells have been cultivated in micro-systems with and without flow, and cell proliferation dynamics have been monitored with image analyzing. Simultaneously, a numerical model has been developed in order to predict cell growth under fluid flow. Cell population dynamic is simulated using a three-dimensional cellular automaton, while the fluid flow is described using the Lattice-Boltzmann method (LBM). Experiments and numerical results show the influence of fluid induced shear stress on cell proliferation

Benzodiazepine dependence: Focus on withdrawal syndrome

Benzodiazepines are potentially addictive drugs: psychological and physical dependence can develop within a few weeks or years of regular or repeated use. The socioeconomic costs of the present high level of long-term benzodiazepine use are considerable. These consequences could be minimised if prescriptions for long-term benzodiazepines were decreased. However, many physicians continue to prescribe benzodiazepines and patients wishing to withdraw receive little advice or support. Particular care should be taken in prescribing benzodiazepines for vulnerable patients such as elderly persons, pregnant women, children, alcohol- or drug-dependent patients and patients with comorbid psychiatric disorders. The following update gives recent research results on the withdrawal pathophysiology and practical information in order to treat or prevent benzodiazepine withdrawal syndrome.N. Authier, D. Balayssac, M. Sautereau, A. Zangarelli, P. Courty, A.A. Somogyi, B. Vennat, P.-M. Llorca and A. Eschalie

New insights into nanoscale organization of dentin

Dentin is the main tissue of the tooth, located between the enamel and the pulpal cavity. Dentin displays a hierarchical organization with microscale porosities surrounded by a dense mineral collar (peritubular dentin, PTD) called tubules, embedded in a matrix of intertubular dentin (ITD). At the nanoscale, the ITD matrix is made up of an entanglement of collagen fibrils (roughly 100nm diameter) and mineral platelets (roughly 5nm thick). X-Ray ptychotomography (PXCT), a recent nano-tomography technique, has already been used by Zanette et al. to analyze the dentin nanostructure, reaching a resolution of about 160nm, superior to the collagen fibril diameter. We present here a new PXCT study with a resolution of 50nm.Two healthy teeth were examined, one permanent and one primary. The samples were cut and polished to the micron using classical techniques. Cylindrical samples of roughly 20 microns in height and 20 microns in diameter were extracted, with a first step of coarse micromachining using a Xenon Plasma FIB-SEM (TESCAN FERA 3), followed by the extraction and fixation of the sample on the pin, using a Gallium FIB-SEM (Helios 660, FEI).The PXCT experiments were performed at Synchrotron Soleil on the SWING beamline. A coherent X-ray beam with an energy of 8 keV was focused ahead of the sample position, resulting in a 4 µm probe size. For each tomographic projection, about 500 diffraction patterns were recorded with an exposure time of 0.1 s each by scanning the sample with a step size of 1 µm. This procedure was repeated for about 600 evenly spaced angular positions of the sample which rotated over 180°.Our observations confirm the presence of lateral branches surrounded by a dense collar linking tubules together and a fibrillar mesh globally located in planes perpendicular to the tubule main axis in agreement with the literature. We could also distinguish local heterogeneities in this organization: the interface between ITD and PTD exhibits fibrils oriented along the tubule main axis and there are local differences in mineral density that cannot be seen on averaged/global estimations. More strikingly, the collagen fibrils 3D organization in intertubular dentin can also be observed, a direct consequence of the very high achieved resolution

New insights into nanoscale organization of dentin

Dentin is the main tissue of the tooth, located between the enamel and the pulpal cavity. Dentin displays a hierarchical organization with microscale porosities surrounded by a dense mineral collar (peritubular dentin, PTD) called tubules, embedded in a matrix of intertubular dentin (ITD). At the nanoscale, the ITD matrix is made up of an entanglement of collagen fibrils (roughly 100nm diameter) and mineral platelets (roughly 5nm thick). X-Ray ptychotomography (PXCT), a recent nano-tomography technique, has already been used by Zanette et al. to analyze the dentin nanostructure, reaching a resolution of about 160nm, superior to the collagen fibril diameter. We present here a new PXCT study with a resolution of 50nm.Two healthy teeth were examined, one permanent and one primary. The samples were cut and polished to the micron using classical techniques. Cylindrical samples of roughly 20 microns in height and 20 microns in diameter were extracted, with a first step of coarse micromachining using a Xenon Plasma FIB-SEM (TESCAN FERA 3), followed by the extraction and fixation of the sample on the pin, using a Gallium FIB-SEM (Helios 660, FEI).The PXCT experiments were performed at Synchrotron Soleil on the SWING beamline. A coherent X-ray beam with an energy of 8 keV was focused ahead of the sample position, resulting in a 4 µm probe size. For each tomographic projection, about 500 diffraction patterns were recorded with an exposure time of 0.1 s each by scanning the sample with a step size of 1 µm. This procedure was repeated for about 600 evenly spaced angular positions of the sample which rotated over 180°.Our observations confirm the presence of lateral branches surrounded by a dense collar linking tubules together and a fibrillar mesh globally located in planes perpendicular to the tubule main axis in agreement with the literature. We could also distinguish local heterogeneities in this organization: the interface between ITD and PTD exhibits fibrils oriented along the tubule main axis and there are local differences in mineral density that cannot be seen on averaged/global estimations. More strikingly, the collagen fibrils 3D organization in intertubular dentin can also be observed, a direct consequence of the very high achieved resolution