IADR Abstract Archives
A Photographic Method to Estimate Shade Change Due to Bleaching
Objectives: Tooth bleaching has become popular, but there is still no reliable method to accurately measure shade changes. The most common approach currently involves matching shade guides to the teeth before and after bleaching, which is highly subjective. This method depends on factors such as ambient lighting, the observer's visual acuity, and the condition of the teeth's surroundings, making it inconsistent.
Our objective is to create a reproductive method and assess an in vitro photographic technique for measuring shade changes resulting from bleaching.
Methods: A Sony Alpha NEX-5N camera was used with 1/5 shutter speed, F3.5 aperture, and ISO 100. A polarizing filter was positioned at a 90-degree angle to the light source's polarization, creating a cross-polarized setup. The lighting system used dual 60 Hz LED lights, each with 0-degree linear polarizing filters and light diffusers. A dark box was employed to prevent reflections and maintain consistent lighting conditions. Six samples were matched to a shade guide, bleached for 1 hour in 10% Hydrogen Peroxide, rinsed with distilled water, and photographed. The samples were then soaked in distilled water for 7 days and rephotographed. Blue intensity in the RGB images was measured using ImageJ software.
Results: The blue intensity for each stage is shown in the graph. The paired t-test comparing the Blue intensity before and after bleaching is significant at p=0.0092; where the comparison after bleaching and at 7 days is not significant at p=0.0764.
Conclusions: The developed photographic method provided consistent and objective results for measuring shade changes due to bleaching. Significant differences were observed between pre-bleaching and post-bleaching stages (p=0.0092), and changes between post-bleaching and 7 days later were not significant (p=0.0764). This technique offers a reliable, reproducible approach for assessing bleaching effects through quantifiable data.
Our objective is to create a reproductive method and assess an in vitro photographic technique for measuring shade changes resulting from bleaching.
Methods: A Sony Alpha NEX-5N camera was used with 1/5 shutter speed, F3.5 aperture, and ISO 100. A polarizing filter was positioned at a 90-degree angle to the light source's polarization, creating a cross-polarized setup. The lighting system used dual 60 Hz LED lights, each with 0-degree linear polarizing filters and light diffusers. A dark box was employed to prevent reflections and maintain consistent lighting conditions. Six samples were matched to a shade guide, bleached for 1 hour in 10% Hydrogen Peroxide, rinsed with distilled water, and photographed. The samples were then soaked in distilled water for 7 days and rephotographed. Blue intensity in the RGB images was measured using ImageJ software.
Results: The blue intensity for each stage is shown in the graph. The paired t-test comparing the Blue intensity before and after bleaching is significant at p=0.0092; where the comparison after bleaching and at 7 days is not significant at p=0.0764.
Conclusions: The developed photographic method provided consistent and objective results for measuring shade changes due to bleaching. Significant differences were observed between pre-bleaching and post-bleaching stages (p=0.0092), and changes between post-bleaching and 7 days later were not significant (p=0.0764). This technique offers a reliable, reproducible approach for assessing bleaching effects through quantifiable data.
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