Desenvolvimento e caracterização de resinas de reduzida tensão de contração

Abstract

The polymerizaion process of resin-based materials used in dentistry usually produces the contraction stress phenomenon, which may lead to several negative events, thus compromising the restorative treatment. Hence, the aim of this thesis was firstly to revise the literature by means of a systematic review with meta-analyses regarding the possible strategies available for reduce the contraction stress produced by resin-based materials; in addition, the present thesis aimed to investigate the effect of elastomeric monomers (exothanes) and polymer-based nanofibers on the contraction stress of experimental resins. Regarding the systematic review, which was performed following the PRISMA guideliness, 77 studies were included in the review, which collectively demonstrated the existence of several possible strategies to reduce the contraction stress phenomenon of resin-based materials. Regarding the effect of the Exothanes, all Exothanes investigated resulted in lower contraction stress when compared to the control (UDMA). Moreover, depending on the Exothane type, an improved polymerization performance was obtained. Regarding the effect of nanofibers, which were fabricated via electrospinning, the greater the contente of nanofibers incorporated into the experimental resins, the greater the potential to reduce contraction stress. Furthermore, the nanofibers did not alter the other physico-mechanical properties tested. In conclusion, Exothanes and polymeric nanofibers may be used as contraction stress reducing agents of resin-based materials, showing potential application for the development of new dental materials.