This study will evaluate the biocompatibility of calcium aluminate cement (EndoBinder, Binderware) in comparison to Mineral Trioxide Aggregate (MTA, Ângelus) and calcium hydroxide cement. For this, the following in vivo tests will be conducted: subcutaneous implantation in rats, direct application (capping) on pulp tissue and application in bone defects. For subcutaneous tissue implantation, 30 rats (Rattus norvegicus, Wistar) will be used. Polyethylene tubes (1.5 mm X 10 mm) containing the materials will be implanted in the dorsum of the animals. After the experimental periods of 7, 30 and 90 days, biopsies will be performed, which will be processed for further analysis of tissue response in light microscopy. For molecular evaluation of the inflammatory process of the peri-implant tissue, the RNAm will be extracted and submitted to analysis by real-time PCR to pro-inflammatory cytokines. For pulp capping test, 60 sound molar of rats will be submitted to cavities class I preparation, followed by mechanical exposure of the pulp tissue. Thus, the teeth will be separated into 3 groups (n=15) according to the cement used as pulp capping agent: G1 - EndoBinder (Binderware); G2 - White MTA (Ângelus) and G3 - calcium hydroxide. Finally, the cavities will be restored with zinc oxide and eugenol based-cement (IRM, Dentsply). In group G4 (positive control, 15 teeth), the cavity will be completely filled with IRM, in direct contact with the exposed pulp tissue. After pre-determined periods of 7, 30 and 90 days, the teeth will be extracted and submitted to histological processing for microscopic analysis. To evaluate the response of bone tissue to the studied cements, these materials will be placed into bone defects prepared mechanically in right and left posterior femur of 30 animals, as follows: G1 - EndoBinder (Binderware); G2 - White MTA (Ângelus) and G3 - calcium hydroxide (n=15). In the control group (G4), only the blood clot will remain within the surgical sites. After 7, 30 and 90 days, biopsies (n=5) of bone tissue will be performed and the animals sacrificed immediately. After fixation, decalcification and laboratory processing, the response of bone tissue in contact with the materials will be analyzed microscopically. For all experimental protocols proposed, specific histological events will be evaluated and quantified using a score system, whose numerical values obtained will be submitted to appropriate statistical tests.
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