Color stability, surface roughness, and surface porosity of acrylic resins for eye sclera polymerized by different heat sources.

Purpose: The aim of this study was to evaluate the color stability, surface roughness, and surface porosity of acrylic resins for eye sclera polymerized by different heat sources and submitted to accelerated artificial aging (AAA).
Materials and Methods: Three groups of ten specimens each were formed according to the heat source used during the polymerization cycle: GI-short cycle, GII-long cycle, and GIII-dry-heat oven. The groups were submitted to color spectrophotometry through the CIE L a b system and to surface roughness and porosity analysis using a Surfcorder IF 1700 profilometer. After the tests, specimens were submitted to AAA, with a maximum aging time of 384 hours, corresponding to a year of clinical use. After aging, the color and roughness of each group were assessed.
Results: The results showed that the variability of DeltaE was clinically unacceptable for all groups but the method of polymerization was insignificant (p > 0.05) for color change. For roughness, polymerization cycle was significant for the results. GIII (0.23 +/- 0.06) presented the highest roughness difference (before and after AAA), statistically significant (p < 0.05) from GII. No statistically significant difference could be found among groups when considering the porosity test.
Conclusion: It may be concluded that irrespective of the type of heat used for polymerization, there was an intense color alteration, to clinically unacceptable levels, when the specimens were submitted to AAA. For the other properties, alterations were less intense.