The purposes of this study were to examine and compare the effectiveness of bleaching and influences on the treated surfaces of KTP laser-office bleaching material with another office bleaching material. Ten clean-scrubbed brown egg shells from store-bought eggs were divided into two groups; one was bleached with Smartbleach containing mainly 55% hydrogen peroxide and the other was bleached with Shofu HiLite containing mainly 35% hydrogen peroxide. Color changes and roughness of treated surfaces were measured, and the surface morphology was observed by scanning electron microscopy (SEM). Statistical analyses were performed using the Mann-Whitney U test or Kruskal-Wallis test, and a probability of less than 5% was considered significant. Both materials tested showed that the bleaching effect depended on the irradiated time, and that the bleaching effect by Smartbleach was significantly greater than that by Shofu HiLite. There was no significant difference between the two groups in surface roughness and there was no clear difference between the two groups in treated surface morphology by SEM. These results showed that the bleaching effect by Smartbleach was significantly greater than that by Shofu HiLite, while no significant difference in influence on the treated surfaces was found.
The Committee of Clinical and Safety Training held two educational seminars and two safety courses from 2013 to 2014. We conducted a questionnaire study and obtained 56 valid answers of incidents and accidents involving laser dental treatment. Most incidents and accidents were emphysema, followed by mis-irradiation, equipment failure, broken irradiation tips, and not wearing safety goggles, respectively accounting for 23, 16, 14, 13 and 11%. These results suggest that laser dental treatment requires different risk management than regular dental treatment. Additionally, it is necessary periodically to hold educational seminars and safety courses on the use of dental lasers.