Root canal treatment of dilacerated second maxillary premolars : planning the shaping procedure

This article aims at investigating endodontic anatomical variants in the human maxillary premolars allowing the planning of safer and faster shaping procedures. Endodontic literature describes maxillary 2nd premolars as some of the easiest teeth to treat, as they have either one or two straight canals. Rarely they may sometimes have two dilacerated canals. This paper reports two clinical cases of maxillary premolars whose anatomy is quite unusual. In the first case report we describe a maxillary 2nd premolar with a single root and two dilacerated merged canals. The second case report concerns the retreatment of a maxillary 2nd premolar with a single root and two independent dilacerated canals, and even some lateral canal. In dilacerated anatomy, canal scouting step might cause some procedural errors. To avoid these procedural errors, we propose a modern step down technique using at first a rotary NiTi glide path instrument, to go up to the 2/3 of root canal length or until to the first impediment. This would allow an easy apical scouting of the last millimeters of endodont and increase the volume of the irrigants in the apical region. In this way since a safer and faster shaping procedure could be performe

A New SLC10A7 Homozygous Missense Mutation Responsible for a Milder Phenotype of Skeletal Dysplasia With Amelogenesis Imperfecta

International audienceAmelogenesis 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

A New SLC10A7 Homozygous Missense Mutation Responsible for a Milder Phenotype of Skeletal Dysplasia With Amelogenesis Imperfecta

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

Characterization of bioceramics and evaluation of their bioactive potentials

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

Caractérisation de biocéramiques et évaluation de leurs potentiels bioactifs

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

Caractérisation de biocéramiques et évaluation de leurs potentiels bioactifs

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

Characterization of bioceramics and evaluation of their bioactive potentials

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

Unusual Maxillary First Molars with C-Shaped Morphology on the Same Patient: Variation in Root Canal Anatomy

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

Microscopic and Chemical Assessments of the Filling Ability in Oval-Shaped Root Canals Using Two Different Carrier-Based Filling Techniques

Objectives: The aim of this study was to assess the filling ability in oval-shaped canals using two different carrier-based filling techniques. Materials and methods: Twenty-four human mandibular premolars with one oval canal were selected. Canals were shaped using WaveOne Gold Primary and ProGlider. Samples were divided into two groups and filled as follows: Thermafil and GuttaCore. The proportions of gutta-percha-filled areas (GPFAs), sealer-filled areas (SFAs), and void areas (VA), at 2 and 5 mm, were analyzed using optical numeric microscope, scanning electron microscope, and energy-dispersive X-ray. Statistical analysis: Data were compared by Kruskal-Wallis one-way analysis of variance on ranks, with statistical significance set at α = 0.05. Results: At 2 and 5 mm distances from the apex, this study discloses no statistically different filling ability for the two techniques. Concerning each sample treated using both filling systems, the presence of tags was visualized. At working length (WL)-5, and WL-2, the maximum tag penetration depth for the GuttaCore group into the dentinal tubules was, respectively, 96 μm and 48 μm, whereas the values in the thermafil group were 109 μm, and 55 μm, respectively. Conclusions: Our results clearly show that Thermafil and GuttaCore can fill oval-shaped canals in appropriate way. Furthermore, we can state that the GuttaCore obturator allows to preserve the same filling ability than Thermafil obturator, in view of the fact that there was no difference, in terms of GPFA, SFA, and VA between the two different carrier-based obturation technique

Effectiveness of Etching by Three Acids on the Morphological and Chemical Features of Dentin Tissue.

Aim: The purpose of this study was to evaluate the microscopic and chemical effects of phosphoric acid gel, phosphoric acid liquid, and polyacrylic acid application for 15 seconds (s) on coronal dentin. Materials and methods: Twelve extracted teeth were selected. Three etching acids were used to prepare the dentin surfaces. Scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDX) were used to analyze the chemical and morphological changes of the dentinal surfaces, including the depth of demineralization. Collected data were statistically analyzed by the one-way analysis of variance test. Results: Dentin etched with phosphoric acid gel or liquid showed greater peritubular dentin dissolution, including complete removal of the smear layer. In addition, there were many silica particles on the dentin etched by phosphoric acid gel 37%. The dentin that was etched with 25% polyacrylic acid for 15 seconds showed no smear layer removal. Chemical analysis (EDX) showed that dental surfaces etched with phosphoric acid liquid 37% for 15 seconds showed the strongest mineral dissolution at the calcium surface, with a calcium content of 5.25%. On the other hand, EDX analysis of the dental surface etched with 25% polyacrylic acid showed more surface enrichment in calcium (17.19%). Conclusion: Although phosphoric acid (gel or liquid) 37% cleans the dental surface, phosphoric acid gel precipitates silica particles on the etched dentin surface. These particles cannot be removed by rinsing off this acid. The application of polyacrylic acid for 15 seconds does not noticeably demineralized dentin, nor remove the smear layer. Clinical significance: The clinician should use phosphoric acid (gel or liquid) to clean dental surfaces to prepare them for the bonding process. The low demineralizing effects of the polyacrylic acid permits its use near the pulp