preparation of the mouth gag for a mouse pulpitis model

Création d’un modèle murin d’inflammation de la pulpe à l’aide d’un nouveau bâillon buccal 

The dental pulp, an integral part of the tooth, is responsible for multiple essential functions such as nutrient supply, dentin formation, sensory function, and defense reactions1. Nevertheless, the dental pulp, surrounded by hard tissue, is susceptible to injuries and damages from deep caries, pulpitis, trauma, or subsequent therapies2,3. The absence of functional dental pulp increases the risk of tooth fragility4. Moreover, the loss of pulp vitality in young permanent teeth can adversely affect tooth maturation, and current denture techniques fail to restore the neural feedback offered by healthy pulp4. This situation has led researchers to explore alternative solutions for managing inflamed pulp beyond mere removal.
In 2007, Murray et al. initiated the application of tissue engineering in regenerative endodontics, thereby sparking increased interest in pulp preservation and regeneration5. However, inflamed pulp tissue poses a challenge as cells release inflammatory factors such as IL-6, which recruit inflammatory cells and results in cell necrosis, loss of pulp vitality, and complications in functional recovery6,7. Understanding inflammation and the associated cell death is, therefore, crucial for advancements in the preservation of vital pulp. There are a number of experiments that have been conducted to explore the molecular biology of the inflame pulp in vivo or in vitro8,9. Though in vitro&#160;experiments like 2D or 3D cell cultures have been developed for years and are becoming mature and widely used to test reactions of pulp cells to inflammatory factors, these experiments cannot reflect the interaction between pulp tissue and the systemic immune system10. If the phenomenon being studied is derived from cells of other tissue origin like immune, vascular and nervous system, then pure pulp cell culture will lead to a dead end. Therefore, in vivo experiments are very necessary and referential.
Mice have increasingly become a common choice in inflammation research in vivo&#160;due to their cost-effectiveness, high fertility, and vitality. However, a comprehensive protocol for mice pulpitis model is currently absent, which can serve as a reference. The small size of mice and their sensitivity to stimulation pose significant challenges during experimental procedures. Observing the minuscule teeth concealed deep within the mouse mouth often necessitates the use of a cantilever microscope, notwithstanding the more common presence of desktop microscopes in laboratories. The absence of a mouth opener requires assistance from others. To address this, the group has devised a mouth-gag using readily available materials which aims to provide a standardized and reproducible protocol for constructing the mice pulpitis model. This article details the procedure, covering preoperative preparation, immobilization, pulp exposure surgery, and sample collection on C57 mice. This protocol recommends the use of the mouth-gag, providing information on its structure, production, and application to facilitate other researchers in replicating the procedure.

Pleins feux sur l’auteur : Améliorer la recherche sur la pulpe dentaire grâce à des modèles murins améliorés

Etablissement d’un modèle d’exposition à la pulpe murine avec un nouveau bâillon pour la recherche sur la pulpite

Individual experiments like 2D or 3D cell cultures have been widely used to test the reactions of dental pulp cells. These experiments cannot reflect the interaction between pulp tissue and the systemic immune system. Therefore, in vivo experiments are becoming increasingly popular in endodontic research.C57 mice have increasingly become a common choice in inflammation research on dental pulp due to their cost effectiveness, high fertility and vitality. However, the small size of mice and lack of coordination posed significant challenges during experimental procedures. The fixation process is an important factor that higher the technical threshold.We devised a novel mouth gag using readily available materials and simple assemblies to assist researchers in pulp exposure surgery. According to our research, this mouth gag can significantly shorten the time required for beginners to immobilize the mouth and expose the maxillary first molar of mice.

Préparation du bâillon buccal pour un modèle de pulpite de souris

Pour commencer, redressez un fil d’arc orthodontique de 8 microns d’épaisseur avec votre main gauche tout en gardant la main droite légèrement pliée contre l’arc du fil. À l’aide d’une pince à boucle Young, pliez le bord supérieur du trapèze d’environ huit millimètres au milieu du fil de l’arc. Assurez-vous que le point A se trouve sur le bord du bec de la pince.Tenez maintenant la pince avec la main gauche. Clampez l’extrémité libre du fil d’arc avec le pouce et l’index droits, puis pliez le fil d’arc à partir du point A pour faire un angle de 120 degrés. Placez le fil de l’arc sur une table horizontale pour vérifier s’il est sur un seul plan.Laissez environ neuf millimètres de chaque côté du fil et utilisez une pince pour plier l’extrémité libre à un angle de 75 degrés. Localisez maintenant le point C qui se trouve à environ cinq millimètres du point B.Pliez le fil au point C pour faire un angle de 105 degrés. De même, pliez le fil aux points D et E.Clampez simultanément les pièces IK et KJ.Dupliquez la flexion A, B, C aux points L, J et K, puis pliez l’extrémité libre au point J pour la rendre verticale par rapport au plan IKJ. Pliez un abaisse-langue supplémentaire pour la partie mandibulaire. Fixez le point I à cinq millimètres du point J et pliez l’extrémité libre pour la rendre parallèle à la fois au plan IKJ et à la partie CD.Ensuite, laissez un espace de cinq millimètres à partir du point I et au point H, pliez l’arc verticalement vers les plans IH et JIH. Localisez le point G à cinq millimètres de H et fixez la voie JIHG. Pliez ensuite l’arc au point G.Pliez maintenant l’extrémité libre symétrique au plan KJ.L’extrémité libre après le point F doit être symétrique à l’extrémité libre au point E.Enfin, placez des capuchons en caoutchouc sur les extrémités libres.

Research

JoVE Journal

Medicine

Preparation of the Mouth Gag for a Mouse Pulpitis Model

Establishment of a Murine Pulp Exposure Model with a Novel Mouth-Gag for Pulpitis Research

Pulpitis, a common cause of natural tooth loss, leads to necrosis and loss of bioactivity in the inflamed dental pulp. Unraveling the mechanisms ...

Recherche

Médecine

Using A Mouth Gag for Pulpitis Assessment in Mice

Utilisation d’un bâillon buccal pour l’évaluation de la pulpite chez la souris