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Accelerated Aging Effects on Color and Translucency of Bleaching‐Shade Composites
Author(s) -
PARAVINA RADE D.,
ONTIVEROS JOE C.,
POWERS JOHN M.
Publication year - 2004
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/j.1708-8240.2004.tb00018.x
Subject(s) - composite material , resin composite , materials science , accelerated aging , composite number , mathematics , zoology , biology
Purpose:: This study was performed to evaluate the influence of accelerated aging on the color and translucency parameter (TP) of bleaching‐shade resin composites. Materials and Methods: Thirty‐three bleaching shades and two control conventional shades of microhybrid (MH) and microfill (MF) resin composite specimens ( n = 5) were aged in an accelerated aging chamber set to standard CAM 180 cycles. One side of each specimen was evaluated for surface color and TP changes compared with baseline in increments of 150 kJ/m 2 for intervals up to 450 kJ/m 2 using a spectrophotometer. A ΔE* 3.7 was considered to be a poor match, and the total TP range was divided into three equal parts representing low, medium, and high translucency. Data were analyzed with analysis of variance. Results: Compared to the baseline, ΔL*, Δa*, Δb*, and ΔE* ranges at 450 kJ/m 2 were ‐0.8 to 5.0, ‐0.6 to 1.2, ‐8.3 to 0.0, and 0.7 to 8.6 for MH and 0.2 to 1.3, 0.1 to 1.3, ‐2.5 to 1.1, and 1.7 to 2.7 for MF composites. Scheffé's S intervals ( p < =.05) for comparisons of ΔL*, Δa*, Δb*, and ΔE* values of MH composites between baseline and 450 kJ/m 2 were 1.6, 0.6, 1.7, and 1.5, respectively. Corresponding Tukey‐Kramer intervals for MF composites were 0.7, 0.3, 0.6, and 0.6, respectively. TP values at baseline ranged from 0.9 to 4.3 for MH and from 1.4 to 2.2 for MF composites, whereas ΔTP for baseline minus 450 kJ/m 2 ranged from ‐1.1 to 1.7 for MH and from ‐0.1 to 0.3 for MF composites. Scheffé's S interval ( p < =.05) for comparisons of ΔTP values of MH composites for baseline minus 450 kJ/m 2 was 1.0. Corresponding Tukey‐Kramer interval for MF composites was 0.4. Conclusions: Aging‐dependent color changes at 450 kJ/m 2 were above the limit that indicated a poor match for 18/26 MH, while corresponding values for microfills were within acceptable range. Accelerated aging generally caused decreases in L* (specimens became darker) and a* values (specimens became redder), while b* values increased (specimens became more chromatic) for both MH and MF composites. TP was relatively stable during aging for both MH and MF composites.