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The guideline of this thesis is to add polyphenols to the liquid used for the setting of dental root canal repair cements with the assumption that this family of molecules, known for their ability to adsorb on the surface of all types of materials, promote interparticle interactions within the cement and a part remains available to promote biological effects. The addition of tannic acid (TA) to mineral trioxide aggregate (MTA) cements decreases their setting time, reduces the average grain size and increases the hydrophilicity of the composite materials as well as their mechanical properties in the dry state. But the fact that the polyphenol is strongly hydrophilic with a certain release in water, induces a decrease of the compression resistance at break of the composites doped with TA compared to the 100% hydrated MTA cement. To better understand the effects of polyphenol addition on the properties of this material, the modification of plaster of Paris with different mass fractions of tannic acid and pyrogallol was also studied. The incorporation of active molecules in calcium-based composites could have a positive effect on their mechanical and biological properties. But further studies are still needed with other polyphenols and other composite materials., La ligne directrice de ce travail de thèse consiste à rajouter des polyphénols dans l’eau utilisée pour la prise du ciment dentaire de réparation canalaire dans l’hypothèse que cette famille de molécules, connues pour leur capacité à s’adsorber sur la surface de tous types de matériaux, favorise des interactions interparticules au sein du ciment et qu’une partie reste disponible pour favoriser des effets biologiques. L'ajout d’acide tannique (AT) aux ciments « mineral trioxide aggregate » (MTA) diminue nettement leur temps de prise et la taille moyenne des grains du ciment obtenus et augmente l'hydrophilie des matériaux composites ainsi que leur propriétés mécaniques à l'état sec. Mais le fait que le polyphénol est fortement hydrophile avec une certaine libération dans l'eau, induit une diminution de la compression maximale à la rupture des composites dopés avec de l’AT par rapport au ciment MTA 100% hydraté. Pour mieux comprendre les effets de l’addition de polyphénols sur les propriétés de ce matériau, la modification du plâtre de Paris avec différentes fractions massiques d’acide tannique et de pyrogallol a été étudiée. L’incorporation de molécules actives dans des composites à base de calcium pourrait avoir un effet positif sur leurs propriétés mécaniques et leurs activités biologiques. Mais des études complémentaires restent à mener avec d’autres polyphénols et d’autres matériaux composites.

The guideline of this thesis is to add polyphenols to the liquid used for the setting of dental root canal repair cements with the assumption that this family of molecules, known for their ability to adsorb on the surface of all types of materials, promote interparticle interactions within the cement and a part remains available to promote biological effects. The addition of tannic acid (TA) to mineral trioxide aggregate (MTA) cements decreases their setting time, reduces the average grain size and increases the hydrophilicity of the composite materials as well as their mechanical properties in the dry state. But the fact that the polyphenol is strongly hydrophilic with a certain release in water, induces a decrease of the compression resistance at break of the composites doped with TA compared to the 100% hydrated MTA cement. To better understand the effects of polyphenol addition on the properties of this material, the modification of plaster of Paris with different mass fractions of tannic acid and pyrogallol was also studied. The incorporation of active molecules in calcium-based composites could have a positive effect on their mechanical and biological properties. But further studies are still needed with other polyphenols and other composite materials., La ligne directrice de ce travail de thèse consiste à rajouter des polyphénols dans l’eau utilisée pour la prise du ciment dentaire de réparation canalaire dans l’hypothèse que cette famille de molécules, connues pour leur capacité à s’adsorber sur la surface de tous types de matériaux, favorise des interactions interparticules au sein du ciment et qu’une partie reste disponible pour favoriser des effets biologiques. L'ajout d’acide tannique (AT) aux ciments « mineral trioxide aggregate » (MTA) diminue nettement leur temps de prise et la taille moyenne des grains du ciment obtenus et augmente l'hydrophilie des matériaux composites ainsi que leur propriétés mécaniques à l'état sec. Mais le fait que le polyphénol est fortement hydrophile avec une certaine libération dans l'eau, induit une diminution de la compression maximale à la rupture des composites dopés avec de l’AT par rapport au ciment MTA 100% hydraté. Pour mieux comprendre les effets de l’addition de polyphénols sur les propriétés de ce matériau, la modification du plâtre de Paris avec différentes fractions massiques d’acide tannique et de pyrogallol a été étudiée. L’incorporation de molécules actives dans des composites à base de calcium pourrait avoir un effet positif sur leurs propriétés mécaniques et leurs activités biologiques. Mais des études complémentaires restent à mener avec d’autres polyphénols et d’autres matériaux composites.

Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2077-0383/9/10/3325 Este artículo pertenece al número especial "Root Canal Treatment (RCT): latest advances and prospects". To investigate the influence of pre-endodontic coronal wall restoration on smear layer removal during di erent root canal irrigation strategies, single-root premolars were prepared with a mesio-occlusal cavity. Half were left untreated (G1), while the mesial walls of the remaining half were reconstructed using a resin composite (G2). The specimens were divided into control (ctrl) groups, which used the conventional needle irrigation method, and four experimental subgroups according to irrigation strategy: Sonic activation using the Endoactivator, sonic activation using the EQ-S, mechanical activation using the XP-Endo finisher, and ultrasonic activation using the EndoUltra. Smear layer removal was assessed through SEM and the results were statistically analyzed. At the coronal and middle thirds, no significant di erence (p > 0.05) was detected for G1 and G2, except for the control subgroups (G1ctrl vs G2 ctrl) at the middle third. At the apical third, the smear layer removal was significantly greater for G2 than G1. In G1, both at the middle and apical level, EQ-S and EndoUltra showed greater smear layer removal (p < 0.05) compared to the others G1 subgroups. In G2, at the apical level, the EQ-S and EndoUltra were the most e ective in smear layer removal. Pre-endodontic coronal wall restoration may improve the smear layer removal during root canal irrigation.

A maxillary first molar should be considered a four-canal tooth until proved otherwise; however, a clinician should also be aware of the possibility of the presence of C-shaped root canal configuration with or without possibility of splitting into two or three canals. The two clinical cases reported in this paper describe the endodontic treatment of two maxillary first molars, on the same patient, with uncommon anatomy: the first case is about a maxillary first molar with only one C-shaped root and one oval canal with a large buccolingual diameter, a C1 type according to Fan's classification; the second case, about the contralateral maxillary first molar, is probably the first case documented of a maxillary first molar with a C-shaped root canal and C-shaped root with complete fusion of the three roots, having a C3 configuration.

International audience; Amelogenesis imperfecta (AI) is a heterogeneous group of rare inherited diseases presenting with enamel defects. More than 30 genes have been reported to be involved in syndromic or non-syndromic AI and new genes are continuously discovered (Smith et al., 2017). Whole-exome sequencing was performed in a consanguineous family. The affected daughter presented with intra-uterine and postnatal growth retardation, skeletal dysplasia, macrocephaly, blue sclerae, and hypoplastic AI. We identified a homozygous missense mutation in exon 11 of SLC10A7 (NM_001300842.2: c.908C>T; p.Pro303Leu) segregating with the disease phenotype. We found that Slc10a7 transcripts were expressed in the epithelium of the developing mouse tooth, bones undergoing ossification, and in vertebrae. Our results revealed that SLC10A7 is overexpressed in patient fibroblasts. Patient cells display altered intracellular calcium localization suggesting that SLC10A7 regulates calcium trafficking. Mutations in this gene were previously reported to cause a similar syndromic phenotype, but with more severe skeletal defects (Ashikov et al., 2018;Dubail et al., 2018). Therefore, phenotypes resulting from a mutation in SLC10A7 can vary in severity. However, AI is the key feature indicative of SLC10A7 mutations in patients with skeletal dysplasia. Identifying this important phenotype will improve clinical diagnosis and patient management.