Development of Rat Caries-Induced Pulpitis Model for Vital Pulp Therapy

Area of Science:

• Dental research
• Immunology
• Regenerative medicine

Background:

• Rodent models are vital for vital pulp therapy research due to anatomical and cellular similarities with humans.
• Existing models often use uninfected teeth, limiting the assessment of inflammatory responses post-therapy.
• A caries-induced pulpitis model is needed to better evaluate inflammatory shifts and healing after vital pulp therapy.

Purpose of the Study:

• To establish a caries-induced pulpitis model in rats.
• To evaluate inflammatory changes during wound healing after pulp capping in reversible pulpitis.
• To investigate the role of macrophages in the healing process.

Main Methods:

• Established a caries-induced pulpitis model using conventional rat caries model.
• Utilized immunostaining for inflammatory biomarkers like Toll-like receptor 2 and proliferating cell nuclear antigen.
• Analyzed macrophage polarization (M1 vs. M2) at different caries stages and during wound healing.

Main Results:

• Toll-like receptor 2 and proliferating cell nuclear antigen expression confirmed immune reactions in moderate and severe caries.
• M2 macrophages predominated in moderate caries (reversible pulpitis), while M1 macrophages were prevalent in severe caries (irreversible pulpitis).
• Pulp capping in reversible pulpitis resulted in complete tertiary dentin formation within 28 days; impaired healing was noted in irreversible pulpitis.

Conclusions:

• A successful caries-induced pulpitis model for vital pulp therapy research was established.
• M2 macrophages play a significant role in the early wound-healing stages of reversible pulpitis.
• The model allows for better investigation of inflammatory processes and therapeutic outcomes in infected dental pulp.