Efeito do pré-aquecimento do cimento resinoso nas propriedades físicas e na resistência adesiva à dentina radicular

Abstract

Aesthetic rehabilitative treatments demand the use of materials capable of mimicking dental structures. Fiberglass posts and all-ceramic restorations are among these materials. Cementation of both is usually carried out using resin cements, which, despite numerous advantages, presents a recurrent problem, the possibility of decementation, mainly caused by the difficulty of polymerizing the cementing agent in areas of low light dispersion. The present study aimed to evaluate the effect of preheating on resin-based cementing materials. Two dual activation resin cements, one conventional (NX3 – Kerr Dental) and the other self-adhesive (Maxcem – Kerr Dental) were analyzed at two different working temperatures (ambient – 23ºC and preheated – 69ºC). The determination of the film thickness was carried out according to the IS0 4049-2000 standard. The post-gel polymerization contraction was obtained using extensometers at two different times (immediate photopolymerization and after 5min) and the adhesive strength was determined by push out test in the different root thirds (cervical, middle and apical). The data obtained were submitted to statistical analysis. With regard to the results of film thickness, a significant decrease in values was observed for both cements when preheated. For post-gel polymerization contraction, there was a difference when polymerization was performed immediately or after 5min. However, there was no difference between the temperatures tested. Regarding the bond strength results, both cements showed higher values in the middle e apical thirds at 69ºC when compared to room temperature. The results indicated that preheating resin cements can be a viable alternative to improve the properties of the materials and the adhesion to root dentin.