Optical analysis for effective phototherapy in an LED oral care device

This paper investigates the advanced capabilities of light-emitting diodes (LEDs) in oral care devices, emphasizing their versatility in wavelength control and ability to reach complex areas within the oral cavity. While LEDs enable precise dosage control and adjustable penetration depths, existing oral care devices are often limited to single-wavelength designs, primarily targeting anterior teeth whitening or lateral surfaces, thereby failing to provide comprehensive oral coverage. To address these limitations, this study introduces a novel LED-based oral care device integrating three distinct wavelengths: blue for antibacterial effects, green for anti-inflammatory effects, and red for preventive and therapeutic applications. Using computed tomography (CT) data, upper and lower dental arch trajectories were acquired to design a flexible printed circuit board (FPCB) that conforms to the natural curvature of the dental arch. Strategically placed LEDs on the FPCB ensure uniform light distribution and optimized irradiance across the entire oral cavity. This research systematically determines the optimal design parameters and operating conditions necessary for achieving appropriate irradiance density, including LED placement, operating time, and power control through driving current and duty cycles. The findings demonstrate a practical and effective approach to overcoming the current limitations of LED oral care devices, significantly enhancing their performance and applicability in dental phototherapy.