Effect of hydrogen peroxide on microhardness and color change of resin nanocomposites.
OBJECTIVE
To examine the effect of hydrogen peroxide on the microhardness and color change of resin composites containing nanofillers.


METHODS
Three resin nanocomposites with three different shades and two different tooth whitening agents were used. The specimens were given a 3-week treatment with one of three protocols: (1) 7 hours/day treatment of carbamide peroxide (CP) + 17 hours/day immersion in distilled water (DW); (2) 1 hour/week treatment of hydrogen peroxide (HP) + immersion in DW for the rest of the week; and (3) immersion in DW for 24 hours/day. The microhardness and color changes were measured after treatment.


RESULTS
After treatment with the whitening agents, there was an 8.1-10.7% decrease in the original microhardness. These values were similar to those obtained from the samples treated with distilled water. In the same resin product, the decrease was similar regardless of the test agents used. In most cases, the color change was only slight (deltaE*=0.5-1.4). Hydrogen peroxide enhanced the color change but the absolute color change values were similar in the same product and shade, regardless of the test agent used.
Kwon
Yong Hoon
YH
Department of Dental Materials, School of Dentistry, Pusan National University, Yangsan 626-870, Korea. y0k0916@pusan.ac.kr
Shin
Dong-Hee
DH
Yun
Dong-In
DI
Heo
Young-Joon
YJ
Seol
Hyo-Joung
HJ
Kim
Hyung-Il
HI
D000704:Analysis of Variance; D000077463:Carbamide Peroxide; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D004338:Drug Combinations; D006244:Hardness; D006861:Hydrogen Peroxide; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry; D016877:Oxidants; D010545:Peroxides; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives
C520091:CeramX; D003188:Composite Resins; D004338:Drug Combinations; C509998:Grandio; D016877:Oxidants; D010545:Peroxides; C533204:filtek Z350; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide