Angiogenesis and Cell Organization after Direct Pulp Capping with Simvastatin Mixed with Calcium Hydroxide Compared with Mineral Trioxide Aggregates

Abstract

Abstract Background Mineral trioxide aggregate (MTA) is widely recognized as the gold standard for direct pulp capping (DPC) materials, but it has certain limitations. In this study, a novel combination of simvastatin and calcium hydroxide (SIM-CH) was investigated as a potential DPC material. We aimed to histologically assess the effects of SIM-CH on angiogenesis and cell organization in comparison to MTA.Methods A total of 32 sound maxillary incisor teeth from 16 male New Zealand white rabbits were divided into two groups: Group I received MTA, and Group II received SIM-CH as a DPC material. Class V cavities were prepared in the upper incisor teeth, and the DPC materials were applied. The final restoration was accomplished using light-cured resin-modified glass ionomer. After 1 and 2 weeks, the animals were euthanized, and histological analysis was performed following routine preparation and hematoxylin and eosin (H&E) staining. The pulp region was evaluated, and a scoring system was employed to assess morphological changes in the odontoblastic layer. The odontoblastic layer width (in mm), and blood vessel count were evaluated under ×100 magnification. Kolmogorov-Smirnov test of normality of the distribution of the variables. Comparisons were carried using Wilcoxon signed-rank test. Pearson Chi-square test was used to test association between qualitative variables. Fisher's exact test is used when indicated.Results The findings indicated that there is no statistically significant difference between the tested materials in all tested parameters except for odontoblast cell layer width in the second week between MTA and SM-CH groups, and in MTA in the 1ST and 2nd week. Besides, there was a statistically significant difference in the blood vessels count in SM-CH between the 1ST and 2nd week. Regarding the descriptive analysis, all specimens demonstrated widely distributed congested capillaries. Most of odontoblast cells were arranged in a palisaded pattern with columnar cell bodies.Conclusions Simvastatin has the potential in improving angiogenic and pulp capping properties of calcium hydroxide.