Background: As the importance of the esthetic function of teeth increases, the use of esthetic restoration materials and whitening treatment are increasing. The purpose of this study was to investigate the color change of esthetic restoration materials upon using staining and whitening toothpaste. Methods: Light curing (LC) packable composite resin, LC flowable resin, LC glass ionomer (GI), and self-curing GI specimens were colored in coffee or curry for three hours a day for seven days. After that, regular toothpaste, whitening toothpaste containing hydrogen peroxide, and whitening toothpaste containing activated charcoal were applied for three minutes three times a day for two weeks. Luminosity (L), chromaticity a (a), and chromaticity b (b) were measured using a spectrophotometer once a week. Results: In the coffee-colored group, the change in L2 *a2 *b2 (E2 ) with time was significant (p=0.004), there was no difference for different toothpaste types (p=0.646), and there was significant difference (p＜0.001) for different esthetic restorative materials.The change of E2 in the curry-colored group was significant only for different esthetic restorative materials (p＜0.001). In the coffee-colored group, the L, a, and b values of the light-curing GI showed greater change than other materials after staining and one week after whitening, turning dark, red, and yellow. In the curry-colored group, L did not differ for different materials and times, and a and b showed the greatest difference in light-curing GI after staining and one and two weeks after whitening. Conclusion The use of whitening toothpaste for two weeks was not different from the use of general toothpaste in the removal of staining or whitening. Since light-curing GI is the most vulnerable to coloration, it is recommended that coloring by food chromogen should be explained in advance, before using light-curing GI for teeth restoration.

YH4808 is a novel potassium-competitive acid blocker developed for gastric acid-related disorders. Previous studies indicate its potential to improve symptoms of gastric acid-related disorders. The current study was aimed to find the optimal regimen of YH4808 for night time pH control. This study was performed in two parts. Each was a randomized, open-label, active-controlled, multiple-doses, two-treatment, two-period crossover study conducted in 20 healthy Korean volunteers. Subjects were randomly assigned to one of the four groups.The three groups received different dosage regimens of YH4808 (100 mg twice a day, 200 mg once a day, or 200 mg twice a day), and the fourth group received esomeprazole 40 mg twice a day. The pharmacokinetic parameters demonstrated that the systemic exposure of YH4808 increased in a dose-proportional manner. The difference in the proportion of time above pH 4 over 24 h from the baseline was the greatest in the group receiving YH4808 200 mg twice a day. The values of the area under the effect curve at night time (12 A.M.–7 A.M.) were higher in all YH4808 groups than in the esomeprazole group. However, the differences among the YH4808 groups were not statistically significant (p > 0.05). YH4808 exhibited potential for better pH control during the night in comparison to esomeprazole. The optimal regimen for night time pH control among all the YH4808 regimens was 200 mg twice a day.

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel.There may be more transmissions with this VOC in Korea than reported.