Caracterizações física e química de cimentos experimentais autoadesivos à base de cálcio

Abstract

Objective: To evaluate the Bond Strength (BS), Degree of Conversion (DC), Calcium Release (CR), Flexural Strength (FS), Elastic Modulus (EM) and Viscosity (VS) of experimentally calcium based cements self-etching and self-adhesive. Three experimental cements: A (CONTROL), B (HYDROCAL), C (CLORECAL) were synthesized and evaluated with a commercial cement D (ULTRAPLUS) (Ultra-Blend Plus®- South Jordan, Utah, USA). Methodology: For the BS, the shear test was used, whose samples 1.3mm in diameter and 2mm in height) were adhered to the bovine dentin (n=10) and tensioned in a testing machine (1mm/min) until occurring the displacement. For the DC (n=3), Infrared Spectroscopy with Fourier transform (FTIR) was used. In determining the CR (n = 3) circular samples (1.0mmx0.4 mm) were used and the reading was performed through an atomic absorption spectrophotometer at 3h, 24h and 72h. For FS/ ME (n= 0), bar-shaped samples (7mmx 2mmx1mm) were made and evaluated using a Universal Testing Machine in the three-point flexion test. For VS (n = 30), the variation in the strain rate was determined by a rotational concentric cylinder rheometer. Results: For BS, all experimental materials showed statistically higher values than the commercial material (p <0.01). For the DC, the CONTROL and HIDROCAL cements showed statistically higher values than the others (p <0.01). In relation to CR, CLORECAL and ULTRAPLUS showed statistically higher values after 72 hours (p <0.01). ULTRAPLUS showed statistically the highest FS and the lowest EM (p <0.05). The HIDROCAL and CLORECAL cements showed VS values statistically higher than the others (p <0.01) Conclusion: In general, the experimental cement based on calcium chloride proved to be more promising.