Novos compósitos autorreparáveis para restauração dentária

Abstract

The evolution of dental materials facilitated the practice of the dental surgeon. The main objectives of dental treatments are to reestablish oral health and restore the normal shape and function of dental elements, providing long-term treatment, without aesthetic damage and negative effects for patients. Within this context, considering that the use of composite resins has a wide clinical application, and that the different clinical procedures where they are used require a lot of their mechanical properties and long-term performance, the continuous development of restorative composites is an important line of research. One of the main causes of replacing restorations with composite resins is fracture. Thus, this study seeks to contribute to the evolution of these materials through a systematic review of the current literature and an in vitro study. The objectives were: 1 To systematically review the literature regarding the existence of self-healing systems in dental materials and to map the current stage of technological development of these materials. 2 To develop and evaluate in vitro a new self-repair system that combines the use of two capsules with different monomers in order to optimize the self-repair process and increase the mechanical strength after the initial fracture of the composite. For study 1, two reviewers conducted a bibliographic search until February 2020, an electronic search was performed using the following databases: PubMed (Medline), Embase, Lilacs, Ibecs, Web of Science, Scopus, BBO, Scielo and The Cochrane Library, using the research strategy developed for PubMed (Medline) and adapted for other databases. Articles that added self-healing systems to dental materials were included. Data regarding the type and efficiency of the self-healing system and its influence on the mechanical properties of the materials were analyzed. 889 potentially relevant records 12 studies met all selection criteria and were included in the qualitative analysis, 5 articles were included in the meta-analysis, quantitative analysis, of the self-repair efficiency and elasticity module, 4 articles for flexural strength. In study 2, self-healing capsules were prepared by emulsion polymerization with formaldehyde and urea. With different compositions of self-repairing liquid. The capsules were analyzed for molecular structure with Fourier transform infrared spectroscopy (FTIR / ATR), surface morphology assessed with scanning electron microscopy (SEM). Experimental resins, with and without the addition of self-healing capsules were subjected to the tests of Degree of conversion (CC), flexural strength (σf) and modulus of elasticity (Ef), Evaluation of fracture toughness (KIC) and self-repair efficiency, Scanning electron microscopy (SEM), roughness analysis by atomic force microscopy (AFM). As a result, a new self-repair system for composite resins was developed. The results showed that the evidence in the literature suggests that the addition of self-repairing agents to dental materials can improve the longevity of dental materials, being able to block the continuity of the crack formed. The addition of capsules did not alter the performance of the experimental resin (p> 0.05), and the groups with capsules showed self-healing efficiency. The new auto repair system, self healing efficiency the (22.1 ± 0.08%) in teh recovery of KIC. The review summarized a new trend in dental materials: self-repair systems. In conclusion, the use of these materials in the near future may increase the longevity of dental materials. In the developed composite resin, All tested materials showed self-healing efficiency. The in vitro study demonstrated the use of a self-repairing liquid containing Bisphenol A glycidylmethacrylate – BisGMA, triethylene glycol methacrylate – TEGDMA and as initiators of the reaction benzoyl peroxide and dihydroxyethyl ptoluidine-DHEPT was effective in promoting the repair of cracks in the material.