Acta Odontológica Colombiana (Jan 2018)
Surface roughness of two thermocured acrylic resins used in total dentures bases fabrication after artificial saliva challenge
Abstract
ntroduction: The thermocured acrylic resins are used as base material for teeth due to their aesthetic look, low water retention and solubility, relatively low toxicity, their repairability and their simple processing technique. Objective: To evaluate the super cial roughness of two denture-based acrylic resins exposed to artificial saliva. Methodology: In vitro study was performed, with 30 specimens of acrylic resins, divided into two groups Iv and Vr (n = 15), manufactured from a steel matrix; Two roughness measurements were performed: the initial and nal with the Mitutoyo Rogusimeter, to obtain the Ra (arithmetic mean), Rq (quadratic mean) and Rz(Mean). In between the initial and nal measurements, the specimens were submerged in arti cial saliva at 37 oC, for 60 days period. The data results were tabulated and statistically analyzed with the t-student and Anova tests. Results: Intergroup comparison was made in the baseline and nal values without showing statistical di erence for the Ra variables (1.9 ± 0.83 μm, 2.0 ± 0.72 μm); Rq (2.35 ± 1.01 μm; 2.7 ± 1.0 μm) and Rz (9.7 ± 5.3 μm, 12.7 ± 4.7 μm) for groups Iv and Vr respectively for baseline values; and Ra (0.58 ± 0.29μm, 0.68 ± 0.32μm), Rq (0.64 ± 0.25μm, 0.83 ± 0.39μm) and Rz (2.46 ± 0.88μm; ,03 ± 1.33μm) for nal values in groups Iv and Vr respectively, (p> 0.05). When comparing the intragroup changes in the surface roughness before and after the immersion in saliva, a statistically signi cant di erence was found for the values Ra, Rq, Rz (p <0.05). Conclusions: There is a decrease in superficial roughness for both groups when immersed in artificial saliva.
