Effect of Blue-light on Visual Function in Endodontics Treatment

Objectives: The operative dental microscope has become an indispensable part of endodontic treatment both nonsurgical and surgical. The light source used for a dental microscope includes a blue light wavelength (blue-light). Since dental treatment using microscope continues precision work within a limited visual field for a long time, influence on the visual function to clinical practice is reasoned through a sense of eye fatigue and disorder. In this research, in order to analyze the influence on the microscope and the visual function in detail, a questionnaire survey was conducted on the influence that the operator considers, and based on the result, the vision test was conducted and analyzed.

Methods: Kanagawa Dental University Division of Pulp biology and volunteers were enrolled in subjects in their 20s and 30s. Corrected visual acuity of the subject was 1.0 or more, refraction ± 4 D or less and it was assumed that there was no ophthalmologic disease other than refraction abnormality. Analysis of the vision analyzed the questionnaire and BUT, pupil diameter and miosis rate before and after the root canal treatment of natural extracted teeth. This research was carried out under the approval of Kanagawa Dental University Research Ethics Review Committee (number; 383).

Results: The effects were found to be particularly significant after 30 s. All Subjects in 30 s and beyond have continued medical examination using a microscope for 3 to 5 years. In the halogen light and the LED light, a tendency different from fatigue level and subjective symptoms when using for the same time were observed, but there is a possibility that a difference in visual function that affects depending on the content of blue-light.

Conclusions: It is suggested that the blue-light may increase the burden on the eyes by the results of the visual inspection on halogen and LED.