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The conventional radiotherapy protocol to treat head-and-neck cancer is usually followed by tooth-decay onset. Radiation impact on mineralized tooth structures is not well-understood. This systematic review aimed to collect the recorded effects of therapeutic radiation on tooth chemical, structural and mechanical properties, in relation with their means of investigation.Systematic search (January 01 2012 - September 30 2021) terms were "Radiotherapy", "Radiation effects", "Dental enamel", "Dentin", "Human" and "Radiotherapy" NOT "Laser".PubMed, DOSS and Embase databases were searched.Selected studies compared dental enamel, coronal and root dentin properties before and after in vitro or in vivo irradiation up to 80 Gy.The systematic search identified 353 different articles, with 28 satisfying inclusion criteria. Their reference lists provided two more. Twenty-two studies evaluated dental enamel evolution, nine assessed coronal dentin and eight concerned root dentin. Coronal and root dentin results indicate a major impact of the radiation on their organic matrix. Dental enamel's chemical properties are less modified. Enamel and root dentin's hardness are decreased by therapeutic radiation, but no consensus arises for coronal dentin.Our findings revealed some interesting information about enzymatic degradation mechanisms of dentin organic matrix and highlighted that dental hard-tissue characterization requires highly specific expertise in materials science. That scientific knowledge is necessary to design suitable protocols, adequately analyze the obtained data, and, thus, provide relevant conclusions.Better knowledge and understanding of the mechanisms involved in the degradation of enamel and dentin would enable development of new preventive and therapeutic methods for improved medical care of patients undergoing radiotherapy.

In this article, we aimed to elaborate a universal clinical multidisciplinary protocol in order to facilitate the management of the peg-shaped maxillary lateral incisors, via a case of two upper lateral incisors affected by microdontia. A meticulous clinical analysis, wax up and mock up are crucial to ensure optimal rehabilitation.

Introduction: Clinical photography is an important tool for clinical practice, training and research frequently used across medical specialties. It may provide snapshot images of evolving clinical situations. The aim of this work was to record its contribution in the management of oral mucosal diseases and, to identify the methods of using this tool by carrying out a survey with practitioners specialized in oral pathologies. This allowed us to make recommendations for appropriate use of this tool. Material and methods: An online anonymous questionnaire was sent via email, to practitioners who were member of two associations of French specialists. Results: 51 oral medicine specialists completed the survey. Among them, 48 (94%) used photography in their daily practice. Lack of time or interest was the reasons given by the 3 practitioners who did not use photography. Pictures were mostly taken with smartphones, which provide precise and accurate images, and stored on personal or professional computers. Sharing of images was performed mostly by secured professional or personal email addresses. Consent was obtained verbally in most cases. Conclusion: Photography could be a valuable asset in the practice of oral medicine. However, recommendations for the safety of patient personal data are not always followed.

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements. Special emphasis is made on promising new biomaterials, such as injectable bone substitute and injectable calcium phosphate cements. These materials, which combine biocompatibility, bioactivity and rheological properties, could be good alternatives in endodontics as root canal fillers. They could also be used as drug-delivery vehicles (e.g., for antibiotics and growth factors) or as scaffolds in pulp tissue engineering.

An injectable bone substitute (IBS) made of a suspension of calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. Compared with current filling materials, which are toxic to periapical tissues, calcium phosphate materials, due to their biocompatibility and bioactive properties, may be viewed as possible alternatives. The aim of this study was first to determine if an injectable bone substitute could be used to obtain further healing of apical tissue by the neoformation of a mineralized barrier. In the next step, the paper will focus on rheological measurements as a tool for physical characterisation and on the improvement of the injection technique. Rheology concerns the flow and deformation of the suspension and, in particular, its behaviour in the transient area between solids and fluids. The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. Other experiments with other animal models closer to a Human model have to be performed before human trials.

An injectable bone substitute (IBS) made of a suspension of Calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. The aim of this study was to verify the ability of calcium phosphate ceramic suspension to fill the apical zone of teeth ex vivo (n=40) and in vivo in a sheep model (n=8). The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. In vivo, the presence of blood pressure due to the pulpectomy is a negative parameter to allow a good filling. The scanning electron microscopy revealed mineral formation at the apex level with mineral tissue conduction between the BCP granules but only one tooth showed a good apical filling with a good sealing. The sealing of the apex seems to depend of the amount of BCP granules. Other experiments with other animal models closer to a Human model have to be performed before human trials.

The use of injectable calcium phosphate (CaP) biomaterials in noninvasive surgery should provide efficient bone colonization and implantation. Two different kinds of injectable biomaterials are presently under development: ionic hydraulic bone cements that harden in vivo after injection, and an association of biphasic calcium phosphate (BCP) ceramic granules and a water-soluble polymer vehicle (a technique particularly investigated by our group), providing an injectable CaP bone substitute (IBS). In our study, we compared these two approaches, using physicochemical characterizations and in vivo evaluations in light microscopy, scanning electron microscopy, and three-dimensional microtomography with synchrotron technology. Three weeks after implantation in rabbit bone, both biomaterials showed perfect biocompatibility and bioactivity, but new bone formation and degradation of the biomaterial were significantly greater for BCP granules than for ionic cement. Newly formed bone developed, binding the BCP granules together, whereas new bone grew only on the surface of the cement, which remained dense, with no obvious degradation 3 weeks after implantation. This study confirms that BCP granules carried by a cellulosic polymer conserve bioactivity and are conducive to earlier and more extensive bone substitution than a carbonated-hydroxyapatite bone cement. The presence of intergranular spaces in the BCP preparation, as shown on microtomography imaging, seems particularly favorable, allowing body fluids to reach each BCP granule immediately after implantation. Thus, the IBS functions as a completely interconnected ceramic with total open macroporosity. This new bone replacement approach should facilitate microinvasive bone surgery and local delivery of bone therapy agents. (C) 2003 Wiley Periodicals, Inc.

Although initial results were promising for an injectable bone substitute (IBS) associating a hydroxypropyl methylcellulose (HPMC) polymer vector (Benecel®, 2 w/w %) with biphasic calcium phosphate (BCP), a sensitization reaction occurred probably related to the degree of polymer purity. In this context, Benecel® and another HPMC, E4M® were investigated in the present study. The expected composition of the polymers was confirmed by gas–liquid chromatography. Studies in the guinea pig showed that Benecel® has strong sensitization capacity and E4M® none. Benecel® manifests impurities (30 times more than E4M®) in individual fibers or rounded clumps that are apparently responsible for extreme sensitization. Purification by ultracentrifugation associated with 0.2 μm filtration can decrease sensitization capacity considerably, though with a slight loss of polymer concentration. Fourier transform infrared (FTIR) analysis showed that the impurities were largely cellulose derivatives. However, extraction by organic solvent, followed by FTIR studies and micro-X analysis, detected an oily substance containing carbon and silicon associated with the cellulose derivatives. E4M®, a polymer with no sensitization capacity, could replace Benecel® and improve results with IBS.

This study investigated the in vivo performance of two composite injectable bone substitutes (IBS), each with different calcium-phosphate particles granulometries [40-80 (IBS 40-80) and 200-500 microm (IBS 200-500)]. These biomaterials were obtained by associating a biphasic calcium-phosphate (BCP) ceramic mineral phase with a 3% aqueous solution of a cellulosic polymer (hydroxy-propyl-methyl-cellulose). Both materials were injected for periods of 2, 3, 8, or 12 weeks into bone defects at the distal end of rabbit femurs. Quantitative results on new bone formation, BCP resorption, and staining for tartrate-resistant acid phosphatase (TRAP) activity were studied for statistical purposes. Measurements with scanning electron microscopy and image analysis showed that the final rates of newly formed bone were similar for both tested IBS after 12 weeks of implantation. Bone colonization occurred more extensively during early implantation times for IBS 40-80 than for IBS 200-500. For the latter, BCP degradation occurred regularly throughout the implantation period, whereas it was very intensive during the first 2 weeks for IBS 40-80. Positive TRAP-stained degradation cells were significantly more numerous for IBS 40-80 than for IBS 200-500 regardless of implantation time. With the granulometry of either mineral phase, both tested IBS supported extensive bone colonization, which was greater than that previously reported for an equivalent block of macroporous BCP. The resorption-bone substitution process seemed to occur earlier and faster for IBS 40-80 than for IBS 200-500. Both tested IBS expressed similar biological efficiency, with conserved in vivo bioactivity and bone-filling ability.

9th European Meeting on Injectable Bone and Joint Substitution Materials, LAUSANNE, SWITZERLAND, MAR 01-02, 1999; This in vivo study investigated the influence of two calcium phosphate particle sizes (40-80 mu m and 200-500 mu m) on the cellular degradation activity associated with the bone substitution process of two injectable bone substitutes (IBS), The tested biomaterials were obtained by associating a biphasic calcium phosphate (BCP) ceramic mineral phase and a 3% aqueous solution of a cellulosic polymer (hydroxypropylmethylcellulose). Both were injected into osseous defects at the distal end of rabbit femurs for 2- and 3-week periods. Quantitative results for tartrate-resistant acid phosphatase (TRAP) cellular activity, new bone formation, and ceramic resorption were studied for statistical purposes. Positive TRAP-stained degradation cells were significantly more numerous for IBS 40-80 than IBS 200-500, regardless of implantation time. BCP degradation was quite marked during the first 2 weeks for IBS 40-80, and bone colonization occurred more extensively for IBS 40-80 than for IBS 200-500, The resorption-bone substitution process occurred earlier and faster for IBS 40-80 than IBS 200-500, Both tested IBS displayed similar biological efficiency, with conserved in vivo bioactivity and bone-filling ability. Differences in calcium phosphate particle sizes influenced cellular degradation activity and ceramic resorption but were compatible with efficient bone substitution, (Bone 25:71S-74S; 1999) (C) 1999 by Elsevier Science Inc, All rights reserved.

Fatimi, Ahmed Tassin, Jean-Francois Bosco, Julia Deterre, Remi Axelos, Monique A. V. Weiss, Pierre 39 SPRINGER ANG CY, 1994, JOURNAL OF RHEOLOGY, V38, P85 IGER K, 1989, KAUTSCHUK GUMMI KUNSTSTOFFE, V42, P273; International audience; Calcium phosphate ceramics suspensions (ICPCS) are used in bone and dental surgery as injectable bone substitutes. This ICPCS biomaterial associates biphasic calcium phosphate (BCP) granules with hydroxypropylmethylcellulose (HPMC) polymer. Different ICPCS were prepared and their rheological properties were evaluated in parallel disks geometry as a function of the BCP weight ratio (35, 40, 45 and 50 %). The suspensions show a strongly increased viscosity as compared to the suspending fluid and the high shear rate part of the flow curve can be fitted with a power law model (Ostwald-de Waele model). The fitting parameters depend on the composition of the suspension. A simple device has been used to characterize extrusion of the paste using a disposable syringe fitted with a needle. The injection pressure of four ICPCS formulations was studied under various conditions (needle length and radius and volumetric flow rate), yielding an important set of data. A theoretical approach based on the capillary flow of non-Newtonian fluids was used to predict the necessary pressure for injection, on the basis of flow curves and extrusion conditions. The extrusion pressure calculated from rheological data shows a quantitative agreement with the experimental one for model fluids (Newtonian and HPMC solution) but also for the suspension, when needles with sufficiently large diameters as compared to the size of particles, are used. Depletion and possibly wall slip is encountered in the suspensions when narrower diameters are used, so that the injection pressure is less than that anticipated. However a constant proportionality factor exists between theory and injection experiments. The approach developed in this study can be used to correlate the rheological parameters to the necessary pressure for injection and defines the pertinent experimental conditions to obtain a quantitative agreement between theory and experiments.

L'hypersensibilité dentaire se manifeste par une douleur brève et aiguë émanant de la dentine exposée. Elle peut être due à des stimuli de nature thermique, tactile, osmotique ou chimique et que l'on ne peut imputer à aucune autre forme de défaut ou de pathologie dentaire. La gêne occasionnée peut se manifester sous différentes formes allant d’un léger inconfort à une douleur sévère. Vu l'accroissement de sa prévalence ces dernières années, l’hypersensibilité est aujourd'hui perçue comme un problème de santé publique. Son étiologie est multiple : traumatique, habitudes alimentaires, mauvaise hygiène bucco-dentaire, traitements dentaires, etc. La difficulté face au traitement des hypersensibilités est liée aux nombreuses techniques et thérapeutiques proposées. Les hypersensibilités dentinaires sont généralement traitées soit de manière non invasive en ambulatoire (dentifrices et agents désensibilisants), ou au fauteuil (application d’agents topiques, adhésifs, vernis), soit de manière invasive (composites, chirurgies parodontales). L’objectif du traitement est de diminuer les sensibilités, généralement via l’oblitération des tubulis dentinaires. Le laser en tant que solution thérapeutique pour les hypersensibilités dentinaires a été introduit dans les années 80 avec l’avènement du laser Erbium. Actuellement, de nouveaux lasers, plus performants et plus adaptés pour le traitement des hypersensibilités dentinaires, sont sur le marché, par exemple les lasers de basse fréquence (laser à diode, helium-neon laser), les lasers à moyenne et haute fréquence (Er:YAG, Nd:YAG, laser CO2, etc). Ces différentes technologies laser rendent cet instrument innovant et évolutif, une alternative aux traitements invasifs. Après un rappel des différentes thérapeutiques face à une pathologie courante touchant de nombreux patients, l’objectif de ce travail est de mener une revue systématique de la littérature sur l’efficacité des différents lasers. Quels en sont alors les effets biologiques à court, moyen et long terme et les meilleures stratégies thérapeutiques ?

Les techniques peu invasives telles que la sono abrasion, l’air abrasion ou le laser sont des techniques alternatives à l’instrumentation rotative. La dentisterie opératoire évolue vers une dentisterie préventive et à minima, qui remanie totalement le mode de pratique. L'amélogenèse imparfaite (AI), les lésions cervicales d’usure entrainent des états de surface, différent de l’émail sain, ce qui peut entraîner une modification du protocole opératoire. Il est bien établi aujourd’hui que la teneur minérale des tissus dentaires conditionne la qualité de l’ancrage micro-mécanique des agents adhésifs. Dans une première partie, nous étudierons les différents états de surface de l’émail obtenus suivant différentes techniques de curetage sur émail carié ou altéré. Ensuite, notre étude va nous permettre de décrire ces états de surface et de déterminer le potentiel d’adhésion afin d’essayer de proposer les meilleures stratégies thérapeutiques. Résultats : Les résultats tendent en général à privilégier un prétraitement des surfaces à l’acide orthophosophorique car ceci potentialise la force de liaison, mais ce traitement peut s’avérer agressif dans certaines anomalies de l’émail telle que l’amélogénèse imparfaite

Les résines composites subissent au cours du temps une dégradation et une diminution de leurs propriétés physiques, mécaniques et chimiques. Des changements structurels majeurs se produisent au fil du temps, tels que la dégradation superficielle du matériau ou une altération de la teinte. La dégradation est accélérée par une combinaison de plusieurs facteurs présents dans la cavité orale tels que l’humidité, les variations de pH et de température et les contraintes occlusales. Pour étudier ces comportements, les chercheurs ont mis en œuvre des techniques de vieillissement in vitro, qui permettent de reproduire en quelques jours des dégradations au niveau des matériaux qui seraient perceptibles cliniquement uniquement après plusieurs années. De nos jours, l’évolution industrielle du marché des résines composites est telle qu’il serait compliqué de tester in vivo sur une durée de 5 ou 10 ans les matériaux avant leur commercialisation ; ces moyens de vieillissement en laboratoire des résines composites permettent donc de reproduire plus ou moins fidèlement le vieillissement in vivo que subissent les restaurations durant leur utilisation clinique en peu de temps. Il permet ainsi de prédire approximativement le futur comportement clinique de la résine composite. Cependant, il est évident qu’il ne permettra jamais de reproduire exactement les conditions auxquelles sont exposées les résines composites au sein de la cavité orale.

The use of amalgams has been declining for several years in favor of materials imitating the color of natural teeth: composite resins. In addition to traditional composite resins, new resins (Siloranes, Ormocer, Compomers, Giomers) have appeared on the market. However, following the placement of these materials to restore the teeth, monomers and other chemicals are released into the oral cavity. Substances released have various effects on the mouth. In addition, research is being undertaken to reduce or even eliminate these more or less toxic substances by improving the properties of resins. It becomes necessary to be able to identify them and limit their release in order to have the most biocompatible therapeutic possible.; L’utilisation des amalgames est en baisse depuis plusieurs années au profit de matériaux imitant la couleur des dents naturelles : les résines composites. En plus des résines composites traditionnelles, de nouvelles résines (Siloranes, Ormocer, Compomères, Giomers) ont fait leur apparition sur le marché. Cependant, suite à la mise en place de ces matériaux pour restaurer les dents, des monomères et d’autres substances chimiques sont libérés dans la cavité buccale. Les substances relarguées provoquent divers effets au niveau buccal. De plus, la recherche est engagée pour diminuer voire supprimer ces substances plus ou moins toxiques en améliorant les propriétés des résines. Il devient nécessaire de pouvoir les identifier et de limiter leur libération afin d’avoir une thérapeutique la plus biocompatible possible.