Article information
Year 2019 Volume 69 Issue 1 Page 53-59
Effect of Bleaching Methods on Resin Impregnated Tooth
Color, Resin impregnated tooth, Tooth bleaching
The purpose of this research was to investigate the effect of bleaching methods on teeth that have a
resin impregnated layer. Half of the buccal of 40 extracted maxillary premolars were luted with orthodontic resin
cement and smooth polished with a tungsten carbide bur. The other half was used as a control group. The initial
color difference between both halves was unnoticed (ΔE<3). Teeth were divided into the following four groups: 1)
bleached with 10 % carbamide peroxide for 8 hours per day; 2) bleached with 20 % carbamide peroxide for 8 hours
per day; 3) in-office-bleaching with 40 % hydrogen peroxide every 6 days, and 4) in-office-bleaching with 40 %
hydrogen peroxide (1 day) followed by 10 % carbamide peroxide for 8 hours per day. The difference of color (ΔE)
between the cemented site and the controlled site was evaluated every three days using VITA Easyshade®V. The
bleaching procedures were continued until the ΔE less than 3. On day 3 of bleaching, the difference of color
between resin impregnated area and controlled area obviously increased in all the groups (ΔE>3). Group 3 showed
the highest color contrast followed by groups 2, 4 and 1 respectively. At day 6, the only increase in contrast was
with group 1 while the other group decreased. The unnoticeable color difference (ΔE<3) of group 3 was at day 6,
of group 4 and 2 were at day 9 and of group 1 was at day 15. All bleaching methods created color-mismatch. A
high concentration of bleaching gel caused a high contrast. However, it could reduce the contrast faster.