Background: Calcium silicate cements are biocompatible materials, and can help in repair of osseous defects.
Objective: This study was conducted to evaluate and compare the tissue response to an experimental material (laboratory prepared) versus white MTA and white Portland cement implanted in a rat model.  Materials and methods: The experimental highly purified calcium silicate based material was synthesized denovo in the lab from pure oxides, then tissue response was evaluated on adult Sprague-Dawley rats. Critical size bone defect was done at the middle third of the lateral surface of the right tibia in 75 rats. The bony defect was either left untreated to heal spontaneously in animals of the control group (15 rats) or filled with four different materials (15 rats each). At the end of the experimental periods for each subgroup tibia were dissected for histological analysis and evaluation of inflammatory reaction and newly formed bone. Data were collected, tabulated and statistically analyzed. Results: Within the limitations of this study, it was found that there was a decrease in inflammatory cell count as the wound healing process moves towards formation of granulation tissue and fibrous encapsulation of the different implanted materials, as well as deposition of newly formed bone throughout the experimental periods. Conclusion: The synthetic materials (laboratory manufactured) seemed to have comparable biological properties to those of commercially available bioactive materials. These experimental materials have an intense tissue inductive capacity, and also the incorporation of nanotechnology in the experimental material showed an intense biological effect in tissue regeneration.