Evaluation of Al₂O₃-0,5B₂O₃-SiO₂ composite particles produced by spray pyrolysis for use in dental resin

ABSTRACT

Dental restorations that are performed with composite resins present a very satisfactory aesthetic appearance, with a color close to that of the tooth and acceptable mechanical properties. The great challenge of these resins is that they have the same, or similar, mechanical performance as the original tooth. The present work was developed with the objective of evaluating the inorganic particles of the compound Al₂O₃-0,5B₂O₃-SiO₂, produced by spray pyrolysis (USP) for application in dental composite resins. The synthesis of the particles was carried out using the sol-gel method, with the precursors aluminum nitrate, boric acid and TEOS tetraethylorthosilicate with a pH of 1.5. In order to verify the properties of the particles, physicochemical characterization was carried out using the nitrogen adsorption and desorption method via BET, analysis by SEM, FTIR, XRD, DTA-TGA, NMR and mechanical tensile testing. The images obtained by SEM indicated that the particles were spherical with a mean granulometry of 1.26 ± 0.04 µm, being classified as microhybrid. From the diffractograms, an amorphous characteristic was observed, confirming that the applied synthesis method is efficient for the production of glassy materials. Tests with experimental composite resin showed an acceptable polymerization rate (16 and 9%), but low mechanical compressive strength: between 9.55 and 13.27 MPa.

Keywords
Dental resin; Sol-gel method; Spray pyrolysis