María Alexandra Bedoya Mejía

Background: Understanding the mechanisms underlying dental pain caused by pulpitis in humans has led to the development of animal models, such as the rat, which enable the study of the mechanisms underlying inflammation; the use of these models is considered ethically justified when the anticipated scientific benefits outweigh the potential impacts on animals in the harm/benefit balance. Objective: To develop a rat model of mechanically induced pulpitis and to evaluate the potential impact on animal well-being. Methods: Pulpitis was mechanically induced in male Lewis rats (13–16 weeks, 350–400 g) which were anesthetized and endotracheally intubated. Following pulp exposure, the cavity was sealed with either amalgam (n = 10) or zinc phosphate cement (n = 10). Following recovery and return to their housing, behavioral assessments and histological evaluations using Hematoxylin and Eosin (H&E) staining were conducted in separate cohorts at two time points: 3 h and 5 days following the procedure. Results: A standardized model of mechanically induced pulpitis was established and verified clinically and by histopathological analysis, which showed evidence of the inflammatory process and revealed no statistically significant differences in the scoring of pain, discomfort, or distress, nor in the measurements of food and water consumption or body weight. Conclusions: The behavioral assessments conducted in this study supported the implementation of a safe and easily reproducible model for future research aimed at elucidating the mechanisms underlying pulp inflammation.

Background: due of capsaicin effect on the control of various inflammatory mediators, it has been proposed to modulate inflammatory processes caused by physical assaults to pulp tissue. Purpose: to evaluate the effect of capsaicin diluted in 0.05 % ethanol and its vehicle on PGE2 production, IL-8, IL-6, IL-1β, and IL-12p70 in Human Fibroblasts Pulp (FPH). Methods: concentrations of PGE2, IL-8, IL-6, IL-1β, and IL-12p70 were analyzed by ELISA or flow cytometry in supernatants of FPH at 6 and 8 hours, after being stimulated with capsaicin 5*10-5 M and 2,5*10-5 M and ethanol 0.05% vehicle of capsaicin and compared with unstimulated cells. Results: ethanol 0.05% as a diluent capsaicin, is responsible for the effect on the decrease in the expression of PGE2, IL-8 and IL-6 at the times and concentrations evaluated; and IL-12p-70 was the only cytokine that increased significantly in the presence of capsaicin 2,5*10-5 M at 8h, it is statistically greater than ethanol 0.05%. Capsaicin and ethanol had not significant effect on IL-1β. Conclusion: the effect of capsaicin on FPH, is associated with ethanol 0.05% used as diluent and varies depending on time and the mediator analyzed.