preparation of the mouth gag for a mouse pulpitis model

Oprettelse af en pulp inflammation musemodel ved hjælp af en ny mundgag 

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.

Forfatter Spotlight: Forbedring af tandmasseforskning med forbedrede musemodeller

Etablering af en model for eksponering for musemasse med en ny mundgag til pulpitisforskning

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.

Forberedelse af mundgag til en mus pulpitis model

For at begynde skal du rette en 8 mikron tyk ortodontisk buetråd ud med din venstre hånd, mens du holder højre hånd let bøjet mod trådbuen. Brug en Young loop bøjningstang til at bøje den øverste kant af trapezformet omkring otte millimeter i midten af buetråden. Sørg for, at punkt A er på kanten af tangnæbbet.Hold nu tangen med venstre hånd. Spænd den frie ende af buetråden fast med højre tommelfinger og pegefinger, og bøj derefter buetråden fra punkt A for at lave en 120-graders vinkel. Placer buetråden på et vandret bord for at kontrollere, om den er på et enkelt plan.Efterlad omkring ni millimeter på hver side af ledningen, og brug en tang til at bøje den frie ende til en 75-graders vinkel. Find nu punkt C, som er omkring fem millimeter fra punkt B.Bøj ledningen i punkt C for at lave en 105-graders vinkel. På samme måde skal du bøje ledningen ved punkterne D og E.Clamp IK- og KJ-delene samtidigt.Dupliker A, B, C-bøjningen ved punkterne L, J og K, og bøj derefter den frie ende ved punkt J for at gøre den lodret i forhold til IKJ-planet. Bøj en ekstra tungedepressor til underkæbedelen. Clamp point I fem millimeter fra punkt J og bøj den frie ende for at gøre den parallel med både IKJ-planet og CD-delen.Efterlad derefter et mellemrum på fem millimeter fra punkt I og ved punkt H bøj buen lodret til IH- og JIH-planerne. Find punkt G fem millimeter fra H og clamp JIHG-banen. Bøj derefter buen i punkt G.Bøj nu den frie ende symmetrisk til KJ-planet.Den frie ende efter punkt F skal være symmetrisk med den frie ende i punkt E. Til sidst anbringes gummihætter på de frie ender.

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 ...

Using A Mouth Gag for Pulpitis Assessment in Mice

Brug af en mundgag til pulpitisvurdering hos mus