using a mouth gag for pulpitis assessment in mice

Skapa en musmodell för pulpinflammation med hjälp av en ny mungag 

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.

Författare i fokus: Förbättra tandpulpeforskning med förbättrade musmodeller

Etablering av en exponeringsmodell för murina pulpor med ett nytt munskämt för pulpitforskning

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.

Använda en mungag för bedömning av pulpit hos möss

Börja med att fixera en bedövad mus i ryggläge på en fixeringsplatta. Fäst lemmarna med hudtejp. Komprimera de fria ändarna av en förberedd mungag med tummen och pekfingret.Fäst musens främre framtänder i det trapetsformade spåret mellan de två armarna på mungagen. Se till att armen med tungdepressorn är placerad på underkäken. Kontrollera den första kindtanden i överkäken för att säkerställa att den är fri från karies, trauma och odontogenes.Bedöm det omgivande tandköttet för att säkerställa frånvaro av rodnad, svullnad eller fistel. Kontrollera sedan hälsan hos de motsatta tänderna. Borra sedan den ocklusala sidan av den överkäkens första molar med en tandborr vid 20 000 varv per minut.Ta bort emaljen. Droppa normal koksaltlösning var tredje minut över tanden med en spruta för att förhindra överhettning. Sätt en nummer 8 C+fil på den lägsta positionen i den borrade gropen och stick hål på det sista dentinet för att exponera fruktköttkammaren.Rengör fragmenten runt tanden och ta sedan bort mungagen. Tiden det tog att fixera munnen med mungagen och att hitta den första kindtanden i överkäken förkortades avsevärt jämfört med den traditionella metoden. Exponeringen för massan bekräftades genom mikro-CT och rekonstruktionsmodellering.24 timmar efter operationen hade det mesta av pulpavävnaden behållit sin morfologi.

Research

JoVE Journal

Medicine

Using A Mouth Gag for Pulpitis Assessment in Mice

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 ...

Preparation of the Mouth Gag for a Mouse Pulpitis Model

Förberedelse av mungagen för en modell av muspulpit