Anticancer effect of mastic on human oral cancer cells / 대한구강보건학회지

OBJECTIVES: Mastic is a resinous extract from the stem and main leaves of Pistacia lentiscus, grown only in the Chios island of Greece. Mastic has antibacterial, anti-inflammatory, anticancer, and anti-ulcer activities. Although mastic has been widely studied, its inhibitory effect against cancer cells, especially oral cancer cells, has not been elucidated. The purpose of this study was to assess the anticancer effects of mastic on human oral cancer YD-10B cells. METHODS: YD-10B cells were cultured in 0, 1, 2, 5, and 10 µg/mL mastic for 24 h. Cell count, viability, morphology, colony-forming assay, and DAPI staining were analyzed. RESULTS: Mastic treatment of YD-10B cells resulted in a dose-dependent inhibition of cell growth, and almost all the cells in the 10 µg/mL culture were dead (P<0.05). Mastic treatment induced a morphological change and nuclear fragmentation in the YD-10B cells, and inhibited colony formation of YD-10B cells in a dose-dependent manner. CONCLUSIONS: These results indicate that mastic exhibited anticancer effects on the YD-10B cells through changes in cell morphology and apoptosis.

The Association of Oral Impacts on Daily Performances for Children (C-OIDP), Oral Health Condition and Oral Health-Related Behaviors / 치위생과학회지

The purposes of this study were to investigate the factors affection the Oral Impacts on Daily Performances for Children (C-OIDP) in elementary and middle school students, and identify the association between oral health-related behaviors, oral health condition and C-OIDP. A cross-sectional study was conducted in three schools in Incheon, Asan, Korea. A total of 175 selected children were interviewed by a trained examiner using a questionnaire. Oral Health Related Quality of Life was assessed by the Korean version of C-OIDP. Socio-economic characteristics, oral health-related behaviors, oral health condition and C-OIDP were verified using the questionnaire. ANOVA analysis was performed to determine the oral health and C-OIDP, and multiple regression analysis was performed to determine the factors affecting the C-OIDP. The activities with the greatest effect were eating (28.0%), cleaning teeth (22.9%), and smiling (18.9%). In the logistic regression model, the high item score of C-OIDP was associated with experiencing dental caries and gum pain in the past month. The more the C-OIDP prevalence item, the more the fillng deciduous tooth surface (fs) (p=0.024), caries experienced deciduous tooth surface (dfs) (p=0.049), total caries tooth surface (ds+DS) (p=0.021), and total caries experienced tooth surface (dfs+DMFS) (p=0.047). It can be concluded that the factors affecting C-OIDP are fs, dfs, dfs+DMFS, and gingival pain. Based on these results, we can improve C-OIDP to advance preventive practice.

Evaluation of the whitening and remineralization effects of a mixture of amorphous calcium phosphate, hydroxyapatite and tetrasodium pyrophosphate on bovine enamel / 대한구강보건학회지

OBJECTIVES: The purpose of the present study was to evaluate the whitening effect, morphological and structural changes, and remineralization of the enamel induced by 3 combined agents: amorphous calcium phosphate (ACP), hydroxyapatite (HA), and tetrasodium pyrophosphate (TSP). METHODS: The study was performed on 90 bovine enamel slabs, which were divided into the 6 groups: negative control-distilled water (Group 1); positive control-opalescence F (Group 2); 10% mixed agent (Group 3); 25% mixed agent (Group 4); 50% mixed agent (Group 5); and 100% mixed agent (Group 6). Changes in the shade of the enamel slabs were evaluated using Shade Eye-NCC. Morphological changes were assessed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) was used to determine the remineralizing effect of the three agents on enamel slabs. RESULTS: The change in shade of the enamel (ad*) was noted to increase significantly with increase in whitening frequency in all groups. The value of Δn* was significantly greater in all groups except for the negative control group (P<0.001). SEM revealed that the control group, Group 5, and Group 6 had similar morphologies. The fluorescence lesion areas in the 4 mixture-treated group were significantly smaller than those in the positive control group (P<0.001). CONCLUSIONS: These results showed that the mixture of ACP, HA, and TSP was highly effective for bovine enamel whitening and acted by inducing the remineralization of enamel. CLINICAL SIGNIFICANCE: We evaluated the applicability of a new mixture containing ACP, HA, and TSP. This mixture would be highly useful in aesthetic dentistry because of its whitening efficiency, which does not compromise the enamel's integrity.

Gene expression profile analysis of xylitol-sensitive and xylitol-resistant Streptococcus mutans in 0.5% glucose containing TYE media using DNA chip / 대한구강보건학회지

OBJECTIVES: Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is an effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant S. mutans (XR). The aim of this study is to analyze the difference of gene expression profile of xylitol-sensitive S. mutans (XS) and XR in 0.5% glucose containing TYE media, using a DNA chip. METHODS: S. mutans KCTC3065 was maintained in 0.5% glucose and 1% xylitol containing TYE media, during 30 days at 37degrees C 10% CO2 to form XR. The same procedures without xylitol were repeated for the formation of XS. Both XS and XR were cultured in 0.5% glucose with or without 1% xylitol containing TYE media overnight and total RNA was extracted. RNA from XS was labeled with Cy-3 dye as control, and XR were labeled with Cy-5 as references. DNA chip was hybridized for 18-20 h at 42degrees C. RESULTS: A total of 277 genes of DNA chip data were significantly increased or decreased in XR. There is a total of 174 XR up-regulated genes in 0.5% glucose and 1% xylitol containing TYE media, and a total of 103 down-regulated genes. For compare with results of DNA chip, 11 in up-regulated genes and 10 in down-regulated were verified by RT-PCR. The most abundant increased genes in XR were related to cell envelope, cellular processes, DNA metabolism, transcription, and protein folding and stabilization. The decreased genes in XR were related to amino acid biosynthesis, toxin production and resistance, energy metabolism, ribosomal proteins synthesis, and signal transduction. CONCLUSIONS: These results indicate that the difference of gene expression profile of XS and XR may be in existence. In particular, results of this study for XR up-regulated genes have a lot of similarities with the already published xylitol-related researches and other functional studies.

A study concerning the characteristics of Korean Ni-Ti alloy orthodontic wire / 대한치과교정학회지

To estimate the characteristics of Korean Ni-Ti alloy orthodontic wire, this study investigated compositions, tensile properties, bending properties, heat treatment effects, and ion releasing degrees, and compared these characteristics to those of the imported Ni-Ti alloy wire. The results obtained are as follows; 1. Ti and Ni elements in ORTHOLLOY were in a range showing superelasticity, and there was a little difference in the Ni and Ti contents of ORTHOLLOY as compared with those of SENTALLOY. 2. The results of the tensile test concerning ORTHOLLOY exhibited a superelastic effect, indicating an area of a definite amount of stress in spite of the changes in the range from 2% to 8% in the strain rate. 3. ORTHOLLOY presented higher load values than SENTALLOY in the same deflection values when the wire was tested in three-point bending. A load range displaying a superelastic effect was 80-100g, 140-180g, and l50-200g respectively, in wire diameters of 0.014", 0.016", and 0.018". 4. By heat treatments at 400degreesC and at 500degreesC, a load range showing the effect of superelasticity was lessened by the duration of the heat treatment time. The superelastic effect was destroyed as a result of the 10 minutes heat treatment at 600degreesC. 5. The quantity of the Ni ion released from ORTHOLLOY, tended to be greater than the amount of released Ni ion in SENTALLOY. The Co ion released was very little(<0.01ppm) in SENTALLOY and ORTHOLLOY irrespective of the lapse of time. Released Ni ions on the 1st day were at the maximum, and the releasing rate showed plateaus after three days. 6. The surface morphology of SENTALLOY was relatively regular irrespective of the lapse of time, and the corrosion tendency was not observed. However, the surface morphology of ORTHOLLOY was rather irregular and showed pitting corrosion after immersion.