The Gelatin-Chitosan-Tetraethyl Orthosilicate Calcium Hydroxide Composite as a Potential Dental Pulp Medicament (Study on Expression of COX-2, PGP 9.5, TNF-α and Neutrophils number) [version 1; peer review: awaiting peer review]

Introduction Calcium hydroxide (Ca(OH) 2) is the material of choice for pulp therapy. However, Ca(OH) 2 has drawbacks such as toxicity, poor sealing, and tunnel defect formation. Alternative materials have been developed to provide more biocompatible materials with better dentin formation ability. The objective of this study was to evaluate the effect of composites containing gelatin (G), chitosan (CH), tetraethyl orthosilicate (TEOS), and Ca(OH) 2, namely G-CH-TEOS-Ca(OH) 2 (Extended data) on inflammation of the dental pulp (expression of COX-2, PGP 9.5, TNF-α, and neutrophil number). Materials and methods A total of 16 Wistar rat models of acute pulp injury were prepared and divided into two groups, treatment and control, 8 with each. In the treatment group, we applied a pulp-capping material using G-CH-TEOS-Ca(OH) 2 and Ca(OH) 2. On the 1 st and 3 rd days, rats were sacrificed. Tissue samples from 4 rats in each group were processed for histological preparation. COX-2, PGP 9.5, and TNF-α were observed using immunohistochemical (IHC) staining, and neutrophil numbers were observed using hematoxylin-eosin staining. Image analysis of COX-2, PGP 9.5, and TNF-α expression was performed using ImageJ software. Results The results showed a decrease in COX-2 expression, but not significantly while PGP 9.5 and TNF-α expression were significantly higher than those in the control group. Neutrophil numbers were lower in the treatment group than in the control group, but the difference was not statistically significant. Conclusion The G-CH-TEOS-Ca(OH) 2 composite material may have potential as an exposed pulp medicament by reducing inflammation (COX-2 expression and number of neutrophils) and increasing the regeneration factor (TNF-α expression) and nerve (PGP 9.5 expression).