Effect of bleaching with two different concentrations of hydrogen peroxide containing sweet potato extract as an additive on human enamel: An in vitro spectrophotometric and scanning electron microscopy analysis

Objectives: To evaluate the color change in teeth bleached with two different concentrations of hydrogen peroxide, containing sweet potato extract as an additive, using a spectrophotometer, and to evaluate the surface changes in enamel using a scanning electron microscope (SEM).
Materials and Methods: Baseline color values of 24 artificially stained incisors were obtained using a spectrophotometer. The specimens were divided into two groups of 12 teeth, each based on the concentration of hydrogen peroxide (H ₂ O ₂ ) as follows: Group I - 35% H ₂ O ₂ and Group II - 10% H ₂ O ₂ . One-half of the tooth was bleached with H ₂ O ₂ alone (Subgroup A) and the other half was bleached with a combination of H ₂ O ₂ and sweet potato extract (Subgroup B). Post bleaching the Commission Internationale de l' Eclairage L*, a*, b* (CIEL*a*b*) values were obtained and ΔE was calculated. The surfaces of the samples were examined using SEM.
Results: The mean ΔE values of groups IB (72.52 ± 2.03) and IIB (71.50 ± 1.81) were significantly higher than those of groups IA (65.24 ± 1.02) and IIA (64.19 ± 1.88), respectively, (P < 0.05). The SEM images of groups IB and IIB showed lesser surface irregularities and morphological alterations in enamel.
Conclusion: The addition of sweet potato extract to hydrogen peroxide not only resulted in the restoration of the natural tooth color, but also decreased the effects of bleaching on the enamel morphology, compared to the use of hydrogen peroxide alone.